JP4503749B2 - 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]
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]
For this reason, the applicant has recently proposed an efficient power supply apparatus that does not waste regenerative power as described below.
[0006]
3 is a circuit diagram of the power supply apparatus, and FIG. 4 is a control block diagram of the circuit shown in FIG.
[0007]
In the figure, the same reference numerals as those in FIG. 2 denote the same components, but 10 is 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. As the battery E, for example, one unit battery (one unit) obtained by connecting eight unit cells in series is appropriately determined according to the capacity of the elevator. Q is a capacity meter that detects the amount of charge of the battery E, L is a boosting coil, RT is a current detector, 11 is an emergency power source that is also used as a control power source for a microcomputer, etc. from the battery E in an emergency such as a power failure, Reference numeral 12 denotes an emergency contact for disconnection in the event that the power supply circuit 10 fails.
[0008]
As shown in FIG. 4, 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 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.
[0009]
In the comparator 21, for example, the control signal β 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.
[0010]
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.
[0011]
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.
[0012]
That is, since the comparator 21 outputs a control signal β that alternately turns the transistors Tr1 and Tr2 into the ON state for the same time, the battery E alternately repeats charging and discharging at the same time, and the input voltage Vab of the inverter 3 is set to 350V. Try to keep on.
[0013]
If the input voltage Vab becomes lower than 350 V, the output of the comparator 21 is in the state shown in FIG. 6A, 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.
[0014]
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 is long, and voltage control is performed to maintain the command voltage by giving priority to the charging of the battery E.
[0015]
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.
[0016]
Here, when the charging state 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. For example, when the charge state of the battery E is 80% or more, the limiter value on the charge side of the limiter circuit 20 is set to zero so that only discharge is performed, thereby preventing overcharge and complete discharge. It is possible to extend the life.
[0017]
By charging the battery from the commercial power source when the elevator is stopped, the state of charge of the battery can be maintained at the optimum state by setting the state of charge detected by the capacity meter Q to, for example, about 60%. (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.
[0018]
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.
[0019]
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 continuous power running is expected, such as when working in an office building, the amount of charge of the battery E is taken into account, giving priority to use as an auxiliary power source, and conversely, regenerative operation like noon. 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%.
[0020]
[Problems to be solved by the invention]
However, when the battery E is composed of a plurality of single cells, if the charging and discharging to the battery E is repeated frequently, the terminal voltage for each single cell or each group battery varies, so each unit cell or each group battery There has been a problem that the charge amount of can not be maintained properly.
[0021]
The present invention has been made in view of the above points, and an object of the present invention is to provide an apparatus that can appropriately correct even when the amount of charge of each battery of a plurality of single cells varies.
[0022]
[Means for Solving the Problems]
The present invention includes a commercial power source, an inverter that operates with power from the commercial power source to generate AC power, an electric motor that is driven by AC power generated by the inverter, a battery that can be charged / discharged, A charge / discharge circuit for charging and discharging the battery; a charge control element for closing the charge circuit; a discharge control element for closing the discharge circuit; the charge control element and the discharge By controlling the operation of the charging / discharging circuit by turning on / off the control element, the voltage command of a value corresponding to a constant voltage higher than the full-wave rectified voltage of the commercial power supply is used as a target value to input power to the inverter. A control circuit for controlling the charge control element and the discharge control element by alternately turning on and off the charge control element and the regenerative power from the motor. Which charges Terry, in alternating elevator for supplying electric power generated in the battery to the inverter, includes a current command circuit having a limiter has a function of instructing the charge or discharge to the battery,
1. The battery includes a combination of a plurality of single cells, and includes means for preventing discharge of the battery under predetermined conditions.
2. The battery includes a combination of a plurality of single cells, and includes means for preventing charging of the battery under a predetermined condition.
Is.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
The present invention dares to select the battery charging mode or discharging mode operation under a predetermined condition.
[0024]
【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, FIG. 7 is a control block diagram of the circuit shown in FIG. 1, and the same reference numerals in FIG. 2 and FIG. As shown, 20 'is a limiter for instructing a charging mode in which the discharge-side limiter value (limit value) is set to zero, and 20 "is a limiter for instructing a discharging mode in which the charging-side limiter value is set to zero.
[0025]
E ′ is a battery according to the present invention in which, for example, eight unit cells B are connected in series to form one unit (group battery), and a plurality of such units are arranged in series to form battery E ′. 31 to 31n are insulation amplifiers for detecting the terminal voltages V1 to Vn of the group batteries, 32 is an A / D converter for converting the outputs of the insulation amplifiers 31 to 31n into digital signals, and 33 is a known microcomputer. Each of the converted voltages V1 to Vn is monitored, and if a variation (for example, a difference of about 0.4 v) occurs in these voltage values (for example, about 9.6 v), a signal is sent to the limiter 20 shown in FIG. The current limiter 20 ′ is set as shown in FIG.
[0026]
In this case, the charge mode operation in which only the charging is performed with the discharge-side limiter value set to zero is selected. (Of course, the operation in the discharge mode in which the limiter 20 "for setting the limiter value on the charging side to zero may be selected)
[0027]
As a result, until each terminal voltage of the unit cell B constituting the battery E ′ becomes sufficiently high (for example, until the voltage at which gas generation starts inside the cell), all the unit cells B are thoroughly charged. .
[0028]
At this time, if the capacity meter Q is installed, if the capacity meter Q is preset at the same time, the accumulation of detection errors of the capacity meter Q can be eliminated.
[0029]
In the above description, an example of the operation in the charging mode for the battery E ′ has been described, but it is also possible to reversely operate in the discharging mode.
That is, until the terminal voltage of each unit cell B or each group battery becomes sufficiently low (for example, until about 1/3 or less of the rated voltage of the unit cell B), the limiter value on the charging side is set to zero. "How to continue the operation of the elevator, completely discharge each single battery B to eliminate variation in the amount of charge of the battery, and simultaneously reset the capacity meter Q to eliminate the error of the capacity meter Q Is also possible.
[0030]
【The invention's effect】
As described above, according to the present invention, the regenerative power is appropriately absorbed by the new power supply device while performing normal operation of the elevator, and in the device that supplements the drive power, the unit cell or each group battery constituting the battery Even if the amount of charge varies, the amount of charge can be automatically and appropriately adjusted, and the effects of this new power supply device can be exhibited. Further, when a capacity meter is used, the detection error of the capacity meter can be eliminated.
[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 circuit diagram of a new power supply device.
4 is a control block diagram of the circuit shown in FIG. 3; FIG.
FIG. 5 is a diagram showing signals at various parts in FIG. 4;
6 is a diagram showing signals at various parts in FIG. 4. FIG.
FIG. 7 is a control block diagram of a power supply device showing an embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Commercial power supply 3 Inverter 10 Power supply device E, E 'Battery B Cell B Q Capacity meter
Tr1, Tr2 Transistors 20, 20 ', 20 "Limiter circuit 21 Comparator 1 Triangular wave generator 31, 31n Insulation amplifier 32 A / D converter 1 Microcomputer

Claims (9)

A commercial power source, an inverter that operates with power from the commercial power source to generate AC power, an electric motor that is driven by AC power generated by the inverter, a chargeable / dischargeable battery, and a charge to the battery A charge / discharge circuit for discharging the discharge circuit, a charge control element for closing the charge circuit, a discharge control element for closing the discharge circuit, and turning on the charge control element and the discharge control element A control circuit for controlling the input power to the inverter with a voltage command of a value corresponding to a constant voltage higher than the full-wave rectified voltage of the commercial power supply as a target value by controlling the operation of the charging / discharging circuit by turning off / off And the control circuit alternately turns on and off the charge control element and the discharge control element, thereby causing the battery to be regenerated by regenerative power from the motor. In the AC elevator that supplies the generated electric power of the battery to the inverter, the AC elevator includes a current command circuit having a limiter that functions to instruct charging or discharging of the battery, and the battery includes a plurality of unit cells. A power supply apparatus for an AC elevator comprising a combination and provided with means for preventing discharge of the battery under a predetermined condition. A commercial power source, an inverter that operates with power from the commercial power source to generate AC power, an electric motor that is driven by AC power generated by the inverter, a chargeable / dischargeable battery, and a charge to the battery A charge / discharge circuit for discharging the discharge circuit, a charge control element for closing the charge circuit, a discharge control element for closing the discharge circuit, and turning on the charge control element and the discharge control element A control circuit for controlling the input power to the inverter with a voltage command of a value corresponding to a constant voltage higher than the full-wave rectified voltage of the commercial power supply as a target value by controlling the operation of the charging / discharging circuit by turning off / off And the control circuit alternately turns on and off the charge control element and the discharge control element, thereby causing the battery to be regenerated by regenerative power from the motor. In the AC elevator that supplies the generated electric power of the battery to the inverter, the AC elevator includes a current command circuit having a limiter that functions to instruct charging or discharging of the battery, and the battery includes a plurality of unit cells. A power supply device for an AC elevator comprising a combination and provided with means for preventing charging of the battery under predetermined conditions. 3. The battery according to claim 1, wherein the battery includes a combination of a plurality of group cells, each of which includes a plurality of single cells, and determines the number of the group cells according to the capacity of the elevator. AC elevator power supply. 3. The AC elevator power supply apparatus according to claim 1 or 2, wherein the predetermined condition is when the amount of charge in each unit cell varies. 4. The AC elevator power supply apparatus according to claim 3, wherein the predetermined condition is when the amount of charge in each group battery varies. 6. The AC elevator power supply apparatus according to claim 4, wherein the variation in the charge amount is a state in which terminal voltages of the single cells or the group batteries are different from each other by a predetermined value or more. 3. The AC elevator power supply apparatus according to claim 1, further comprising charging or discharging prevention means for setting a charging-side or discharging-side limiter value to zero. 4. 2. The AC elevator power supply apparatus according to claim 1, wherein when the charging of the battery is completed, the discharge prevention means of the battery is eliminated. 3. The AC elevator power supply apparatus according to claim 2, wherein when the battery is completely discharged, the charging prevention means for the battery is eliminated.

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