WO2013114602A1

WO2013114602A1 - Elevator control device

Info

Publication number: WO2013114602A1
Application number: PCT/JP2012/052384
Authority: WO
Inventors: 宣明妻木
Original assignee: 三菱電機株式会社
Priority date: 2012-02-02
Filing date: 2012-02-02
Publication date: 2013-08-08

Abstract

Provided is an elevator control device with which, even if a protection circuit is not disposed between an inverter and a motor, it is possible, without increasing the size of an apparatus which is connected to a main line, to protect the apparatus against an induced voltage which occurs with the motor. To this end, the control device comprises: a main line which supplies DC power; an inverter which is connected to the output side of the main line and which converts the DC power to AC power; a motor which is connected to the output side of the inverter and raises and lowers an elevator car by rotating using the AC power; an apparatus which is connected to the main line; and a protection means for interrupting the transmission of electricity between either the inverter or the apparatus and the main line according to the speed of the car when the car has an emergency stop.

Description

Elevator control device

This invention relates to an elevator control device.

As an elevator control device, a device that consumes regenerative power in a discharge circuit connected to the bus when the regenerative power due to the induced voltage generated by the motor of the hoisting machine reaches the bus via the inverter has been proposed. . According to the said control apparatus, the braking capability of an elevator can be improved (for example, refer patent document 1).

However, a large induced voltage is generated in an elevator that performs field-weakening control. In order to withstand this induced power, it is necessary to increase the rating of equipment connected to the bus such as an inverter and a discharge circuit. For this reason, the apparatus connected to the bus becomes large.

On the other hand, a control device in which a protection circuit is provided between the inverter and the motor has been proposed. According to the control device, when the induced power is generated, the protection circuit disconnects the connection between the inverter and the motor. For this reason, the said apparatus can be protected, without enlarging the apparatus connected to the bus-line (for example, refer patent document 2).

Japanese Patent Laid-Open No. 3-249075 Japanese Patent No. 3849131

However, it is necessary to increase the rating of the protection circuit so as to withstand the induced voltage. For this reason, the volume of a protection circuit becomes large.

The present invention has been made in order to solve the above-described problems. The object of the present invention is to provide a motor without enlarging the equipment connected to the bus even without providing a protective circuit between the inverter and the motor. It is an object of the present invention to provide an elevator control device capable of protecting the equipment against the generated induced voltage.

An elevator control device according to the present invention includes a bus that supplies DC power, an inverter that is connected to an output side of the bus and converts the DC power into AC power, an output that is connected to the output side of the inverter, and the AC A motor that lifts and lowers an elevator car by rotating using electric power, a device connected to the bus, and the inverter and the device depending on the speed of the car at the time of emergency stop of the car And a protection means for blocking conduction between any of the above and the bus.

According to this invention, even if a protective circuit is not provided between the inverter and the motor, the device can be protected against the induced voltage generated in the motor without increasing the size of the device connected to the bus. .

It is a block diagram of the control apparatus of the elevator in Embodiment 1 of this invention. It is a figure for demonstrating the discharge at the normal time by the control apparatus of the elevator in Embodiment 2 of this invention. It is a figure for demonstrating the discharge at the time of the induction voltage generation by the elevator control apparatus in Embodiment 2 of this invention. It is a figure for demonstrating the discharge characteristic at the time of the normal time by the control apparatus of the elevator in Embodiment 2 of this invention, and the discharge characteristic at the time of an induced voltage generation | occurrence | production. It is a block diagram of the control apparatus of the elevator in Embodiment 2 of this invention. It is a block diagram of the principal part of the control apparatus of the elevator in Embodiment 3 of this invention. It is a block diagram of the principal part of the control apparatus of the elevator in Embodiment 4 of this invention. It is a block diagram of the principal part of the control apparatus of the elevator in Embodiment 5 of this invention.

DETAILED DESCRIPTION Embodiments for carrying out the present 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 a block diagram of an elevator control apparatus according to Embodiment 1 of the present invention.

In FIG. 1, 1 is a motor. The motor 1 is a brushless DC motor (SPM). The motor 1 is provided in an elevator hoist (not shown). A monitoring unit 2 such as an encoder is provided in the vicinity of the motor 1. A sheave 3 is attached to the rotating shaft 1 a of the motor 1. A main rope 4 is wound around the sheave 3. An elevator car 5 is suspended from one side of the main rope 4. A counterweight 6 is suspended from the other side of the main rope 4.

7 is a bus. A converter (not shown) is connected to the input terminal of the bus 7. An inverter 8 is connected to the output terminal side of the bus 7. The input terminal of the motor 1 is connected to the output terminal of the inverter 8. A capacitor 9 is connected between the bus bars 7. The capacitor 9 is composed of an electrolytic capacitor or the like. A discharge resistor 10 is connected between the bus 7 on the inverter 8 side than the capacitor 9. A diode 11 is connected to the discharge resistor 10 in parallel. A semiconductor switch 12 is connected in series to the discharge resistor 10 and the diode 11 as a protection circuit.

One end of a resistor 13 is connected to one of the buses 7 on the converter side of the capacitor 9. The other end of the resistor 13 is connected to the base of the semiconductor switch 12. The collectors of the

insulation switches

14 and 15 are connected to the wiring between the resistor 13 and the base of the semiconductor switch 12. The emitters of these

insulating switches

14 and 15 are connected to the other side of the bus 7 on the converter side of the semiconductor switch 12.

16 is a power supply voltage detection circuit. The power supply voltage detection circuit 16 includes a power supply generation device 17 and a detection circuit 18. The power generation device 17 has a function of supplying a constant voltage. The detection circuit 18 has a function of detecting the voltage of the power supply based on the voltage converted from the voltage of the power supply that supplies the AC voltage to the converter and the voltage supplied from the power supply generation device 17.

19 is an induced voltage detection circuit. The induced voltage detection circuit 19 includes a power supply generation device 20 and a detection circuit 21. The power generation device 20 has a function of supplying a constant voltage. The detection circuit 21 has a function of detecting the voltage between the terminals of the motor 1 based on the voltage converted from the voltage between the terminals of the motor 1 and the voltage supplied from the power generation device 20.

In the above elevator, AC power is supplied from a power source. The AC power is converted into DC power by a converter. The DC power is transmitted to the inverter 8 via the bus 7. At this time, the voltage of the bus 7 is smoothed by the capacitor 9. The DC power is converted into AC power by the inverter 8. The motor 1 is rotated by the AC power. Following the rotation, the sheave 3 rotates. Following the rotation, the main rope 4 moves. Following the movement, the car 5 and the counterweight 6 move up and down in the opposite direction.

Normally, d-axis current zero control is performed in order to rotate the motor 1 efficiently. That is, the motor 1 generates torque with only the q-axis current with the reactive power set to zero. In this case, the maximum value of the voltage between the terminals of the motor 1 is half of the voltage of the bus 7. Corresponding to the maximum value of the voltage, the maximum value of the rotation speed of the motor 1 is limited.

In order to realize high speed rotation of the motor 1, field weakening control is performed. In this case, the effective voltage between the terminals of the motor 1 is increased by passing the d-axis current. For this reason, the voltage between the terminals of the motor 1 is an effective voltage. At this time, the difference between the maximum value and the minimum value of the voltage between the terminals of the motor 1 does not exceed the voltage of the bus 7.

In the above elevator, when a power failure occurs, the car 5 is stopped urgently. In this case, an induced voltage is generated between the terminals of the motor 1. The value of the induced voltage is a product of the magnetic flux φ, the angular velocity ω, and the constant α of the motor 1. When the induced voltage exceeds the voltage of the bus 7, regenerative power due to the induced voltage is transmitted to the bus 7 via the inverter 8.

At this time, the detection circuit 18 detects that the value of the power supply voltage has dropped to zero. In this case, the detection circuit 18 cuts off the supply of voltage to the base of the insulation switch 14. As a result, the insulation switch 14 is turned off. On the other hand, the detection circuit 21 detects an induced voltage as a voltage between the terminals of the motor 1. In this case, the detection circuit 21 maintains the supply of voltage to the base of the insulation switch 14. As a result, the insulation switch 15 maintains the ON state.

In this case, supply to the base voltage of the semiconductor switch 12 is cut off. As a result, the semiconductor switch 12 maintains the OFF state. That is, the conduction between the discharge resistor 10 and the semiconductor switch 12 is interrupted with respect to the bus 7. For this reason, while the induced voltage is generated from the motor 1, no current flows from the bus 7 to the discharge resistor 10 and the semiconductor switch 12.

Thereafter, when the value of the voltage between the terminals of the motor 1 drops to 0, the detection circuit 21 cuts off the supply of voltage to the base of the insulation switch 15. As a result, the insulation switch 15 is turned off. For this reason, the voltage of the bus 7 is supplied to the base to the semiconductor switch 12 via the resistor 13. As a result, the semiconductor switch 12 is turned on. In this case, electrical conduction between the discharge resistor 10 and the semiconductor switch 12 is ensured with respect to the bus 7. As a result, the electric charge accumulated in the capacitor 9 is discharged. Due to the discharge, the voltage of the bus 7 becomes zero. For this reason, the worker can safely perform power restoration work and the like.

When the power supply is restored, the detection circuit 18 detects that the power supply voltage has been restored to a constant value. In this case, the detection circuit 18 supplies a voltage to the base of the insulation switch 14. As a result, the insulation switch 14 is turned on. In this case, the supply of voltage to the base of the semiconductor switch 12 is cut off. As a result, the semiconductor switch 12 is turned off.

At this time, the diode 11 suppresses generation of a surge voltage due to internal inductance of the discharge resistor 10 and parasitic inductance such as wiring.

According to the first embodiment described above, when the car 5 is in an emergency stop, the semiconductor switch 12 is kept in an OFF state until the voltage between the terminals of the motor 1 becomes zero. For this reason, the discharge resistor 10 and the semiconductor switch 12 can be protected against the induced voltage generated in the motor 1.

The generated torque of the motor 1 is determined by the product of the torque constant Pm of the motor 1, the magnetic flux φ of the motor 1, and the current i flowing through the motor 1. On the other hand, in this embodiment, even if the magnetic flux φ of the motor 1 is large, the discharge resistor 10 and the semiconductor switch 12 can be protected. For this reason, the torque required for the motor 1 can be obtained without increasing the value of the current i flowing through the motor 1. Therefore, it is not necessary to increase the volume of the motor 1 or the capacity of the inverter 8.

Further, the semiconductor switch 12 and the insulation switches 14 and 15 may be configured by FETs or IGBTs. In this case, the operation of the semiconductor switch 12 and the insulation switches 14 and 15 can be controlled by controlling the voltages to the gates of the semiconductor switch 12 and the insulation switches 14 and 15.

Embodiment 2. FIG.
FIG. 2 is a diagram for explaining normal discharge by the elevator control apparatus according to Embodiment 2 of the present invention. FIG. 3 is a diagram for explaining discharge when an induced voltage is generated by the elevator control apparatus 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.

As shown in FIG. 2, the electric charge of the capacitor 9 is drawn out by the discharge resistor 10 in normal times. At this time, the voltage of the bus 7 is represented by the following equation. When the capacity of the capacitor 9 is C, the resistance value of the discharge resistor 10 is R, the initial voltage of the bus 7 is V ₀ , and the elapsed time is t, the voltage Vn of the bus 7 is (1)
Vn = V ₀ · e ^{−t / CR} (1)

As shown in FIG. 3, when the induced voltage Vy (= α · ω · φ) exceeds the voltage of the bus 7 during the emergency stop of the car 5, the regenerative power due to the induced voltage reaches the bus 7 via the inverter 8. To do. In this case, the voltage of the bus 7 rises to the induced voltage Vy. At this time, the discharge resistor 10 is a device that only generates heat using the voltage Vy of the bus 7 as a huge voltage source. In this case, after the motor 1 is completely stopped and the induced voltage becomes 0, the electric charge of the capacitor 9 is extracted to the discharge resistor 10.

Next, with reference to FIG. 4, the normal discharge characteristics and the discharge characteristics when an induced voltage is generated will be described.
FIG. 4 is a diagram for explaining normal discharge characteristics and discharge characteristics when an induced voltage is generated by the elevator control apparatus according to Embodiment 2 of the present invention. The horizontal axis in FIG. 4 is time. The vertical axis in FIG. 4 is the voltage of the bus 7.

In FIG. 4, A is the time when the car 5 stops. B is the voltage of the bus 7 when the car 5 stops normally. C is the voltage of the bus 7 when the car 5 comes to an emergency stop.

As shown in FIG. 4, when the car 5 stops normally at time A, the voltage B of the bus 7 decreases rapidly. As a result, the voltage B of the bus 7 becomes almost 0 in a short time. On the other hand, when the car 5 comes to an emergency stop at time A, the voltage C of the bus 7 rises to the induced voltage Vy generated by the motor 1. Thereafter, the voltage C of the bus 7 gradually decreases at a constant rate of change. For this reason, it takes time until the voltage B of the bus 7 becomes zero.

Therefore, in the second embodiment, even when an induced voltage is generated in the motor 1, the charge accumulated in the capacitor 9 can be discharged in a short time.

Hereinafter, the second embodiment will be specifically described with reference to FIG.
FIG. 5 is a block diagram of an elevator control apparatus according to Embodiment 2 of the present invention.

5, the detection circuit 21 detects the voltage between the terminals of the motor 1 and the voltage of the bus 7. The detection circuit 21 compares the voltage between the terminals of the motor 1 with the voltage of the bus 7. When the voltage between the terminals of the motor 1 is equal to or higher than the voltage of the bus 7, the detection circuit 21 supplies a voltage to the base of the insulation switch 15. As a result, the insulation switch 15 maintains the ON state. For this reason, the supply of voltage to the base of the semiconductor switch 12 is cut off. As a result, the semiconductor switch 12 maintains the OFF state. In this case, the regenerative power due to the induced voltage is not consumed by the discharge resistor 10.

On the other hand, when the voltage between the terminals of the motor 1 becomes smaller than the voltage of the bus 7, the detection circuit 21 cuts off the supply of voltage to the base of the insulation switch 15. As a result, the insulation switch 15 is turned off. For this reason, a voltage is supplied to the base of the semiconductor switch 12. As a result, the semiconductor switch 12 is turned on. In this case, the charge of the capacitor 9 is discharged by the discharge resistor 10 in a state where regenerative power due to the induced voltage is not generated.

According to the second embodiment described above, when the voltage between the terminals of the motor 1 is equal to or higher than the voltage of the bus 7, the state where the connection between the bus 7 and the discharge resistor 10 is disconnected is maintained. For this reason, the discharge resistor 10 and the semiconductor switch 12 can be protected against the induced voltage generated in the motor 1. On the other hand, when the voltage between the terminals of the motor 1 becomes smaller than the voltage of the bus 7, the bus 7 and the discharge resistor 10 are connected. For this reason, the electric charge accumulated in the capacitor 9 can be discharged in a short time before the induced voltage becomes completely zero.

Embodiment 3 FIG.
FIG. 6 is a configuration diagram of a main part of an elevator control apparatus according to Embodiment 3 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 FIG. 6, 22 is a converter. The input terminal of the bus 7 is connected to the output terminal of the converter 22. A plurality of capacitors 9 are connected in series to the bus 7 having a high voltage. These capacitors 9 are made of electrolytic capacitors. The withstand voltage of the capacitor 9 is 500V or less. A balance resistor 23 is connected to each capacitor 9 in parallel. A breaker 24 is connected in series as a protection circuit on one side of the bus 7 with respect to the capacitor 9 and the balance resistor 23. The circuit breaker 24 is of a normally closed type. That is, the breaker 24 is normally closed without being supplied with power.

In this case, the voltage of each capacitor 9 is balanced by the balance resistor 23. When the induced voltage of the motor 1 further increases, a large voltage can be applied to each capacitor 9. Therefore, in the present embodiment, when the voltage between the terminals of the motor 1 becomes a predetermined value or more, power is supplied to the circuit breaker 24. The circuit breaker 24 is opened by the electric power. As a result, the connection between the bus 7 and the capacitor 9 is physically disconnected. Note that the predetermined value is set to a value larger than the voltage value of the bus 7 in a normal state and smaller than the withstand voltage of the capacitor 9.

According to the third embodiment described above, the state where the connection between the bus 7 and the capacitor 9 is disconnected is maintained at the time of emergency stop of the car 5. For this reason, the capacitor 9 can be protected against the induced voltage generated in the motor 1.

Moreover, the circuit breaker 24 is a normally closed type. For this reason, power is consumed only when the car 5 is in an emergency stop. As a result, wasteful power consumption can be suppressed.

A circuit breaker 24 may be provided corresponding to the semiconductor switch 12. In this case, the semiconductor switch 12 can be protected against the induced voltage generated in the motor 1.

Embodiment 4 FIG.
FIG. 7 is a configuration diagram of a main part of an elevator control apparatus according to Embodiment 4 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 FIG. 7, the inverter 25 is composed of bipolar elements. Specifically, the inverter 25 is composed of a reverse blocking IGBT. At normal time, the inverter 25 always turns on an element that ensures conduction in the direction from the motor 1 toward the bus 7. In this case, the inverter 25 operates similarly to the inverter 8 of the first embodiment.

On the other hand, when the car 5 is brought to an emergency stop, the inverter 25 turns off the element that secures conduction in the direction from the motor 1 toward the bus 7. As a result, the regenerative power due to the induced voltage is prevented from reaching the capacitor 9.

According to the fourth embodiment described above, when the car 5 is in an emergency stop, the inverter 8 blocks conduction in the direction from the motor 1 toward the bus 7. For this reason, the discharge resistor 10, the capacitor 9, and the inverter 8 can be protected against the induced voltage generated in the motor 1.

Further, it is not necessary to use the circuit breaker 24 of the third embodiment. For this reason, size reduction and cost reduction of a control apparatus are realizable. Furthermore, the wiring from the bus 7 to the capacitor 9 can be shortened. In addition, the wiring can be thickened. For this reason, the inductance of wiring can be made small. As a result, the smoothness of the capacitor 9 can be maximized.

Note that the value of the induced voltage is determined by the maximum speed of the car 5 at the time of emergency stop. For this reason, according to the speed of the car 5 at the time of the emergency stop signal output of the car 5, which method is suitable among the first to fourth embodiments may be selected.

In this case, first, a table may be created by actually measuring the relationship between the rotational speed of the motor 1 and the induced voltage in a state where field weakening control is not performed. Next, the most suitable protection method may be selected based on the maximum speed of the car 5 set for each building where the elevator is installed.

At this time, in consideration of cost performance and space saving, the priority may be increased in the order of the protection method of the first or second embodiment, the protection method of the third embodiment, and the protection method of the fourth embodiment.

Further, in order to improve versatility, all the configurations of the first to fourth embodiments may be provided. In this case, at the time of emergency stop of the car 5, an appropriate protection method is selected from the protection methods of the first to fourth embodiments according to the actual speed of the motor 1 or the car 5 detected by the monitoring means 2. Just choose.

Embodiment 5. FIG.
FIG. 8 is a configuration diagram of a main part of an elevator control apparatus according to Embodiment 5 of the present invention. In addition, the same code | symbol is attached | subjected to the same part as Embodiment 4, or an equivalent part, and description is abbreviate | omitted.

As shown in FIG. 8, a circuit breaker 26 is connected between the inverter 25 and the motor 1. The circuit breaker 26 is of a normally closed type. That is, the breaker 26 is normally closed without being supplied with power. When the voltage between the terminals of the motor 1 becomes equal to or higher than a predetermined value, the breaker 26 is opened by supplying power. As a result, the connection between the inverter 25 and the motor 1 is physically disconnected. The predetermined value of the fifth embodiment is set to be larger than the predetermined value of the third embodiment and smaller than the withstand voltage value of the reverse blocking IGBT of the inverter 25.

According to the fifth embodiment described above, when the voltage between the terminals of the motor 1 is equal to or higher than a predetermined value, the state where the connection between the inverter 25 and the motor 1 is disconnected is maintained. For this reason, even if the induced voltage exceeding the withstand voltage of the reverse blocking IGBT of the inverter 8 of the fourth embodiment is generated, the discharge resistor 10, the capacitor 9, and the inverter 25 can be protected.

The circuit breaker 26 is a normally closed type. For this reason, power is consumed only when the car 5 is in an emergency stop. As a result, wasteful power consumption can be suppressed.

As described above, the elevator control apparatus according to the present invention can be used for an elevator that protects equipment connected to a bus against an induced voltage generated by a motor.

DESCRIPTION OF SYMBOLS 1 Motor 1a Rotating shaft 2 Monitoring means 3 Sheave 4 Main rope 5 Car 6 Balance weight 7 Busbar 8 Inverter 9 Capacitor 10 Discharge resistance 11 Diode 12 Semiconductor switch 13 Resistance 14 Insulation switch 15 Insulation switch 16 Power supply voltage detection circuit 17 Power supply generation device DESCRIPTION OF SYMBOLS 18 Detection circuit 19 Induced voltage detection circuit 20 Power supply generator 21 Detection circuit 22 Converter 23 Balance resistor 24 Breaker 25 Inverter 26 Breaker

Claims

A bus for supplying DC power;
An inverter connected to the output side of the bus and converting the DC power into AC power;
A motor connected to the output side of the inverter and rotating up and down the elevator car by using the AC power;
A device connected to the bus;
Protection means for interrupting conduction between the bus and any of the inverter and the device according to the speed of the car at the time of emergency stop of the car;
An elevator control device comprising:
A detection circuit for detecting a voltage between terminals of the motor;
With
The device comprises a discharge circuit,
The protection means is connected between the bus and the discharge circuit, and maintains a disconnected state between the bus and the discharge circuit until the voltage between the motor terminals becomes zero. The elevator control device according to claim 1.
The detection circuit detects a voltage of the bus;
When the voltage between the terminals of the motor is equal to or higher than the voltage of the bus, the protection circuit maintains a disconnected state between the bus and the discharge circuit, and the voltage between the terminals of the motor is the voltage of the bus. The elevator control device according to claim 2, wherein the bus bar and the discharge circuit are connected when the value is smaller.
The device comprises a capacitor,
The protection means comprises a protection circuit that is connected between the bus bar and the capacitor and maintains a state where the connection between the bus bar and the capacitor is disconnected at the time of emergency stop of the car. The elevator control apparatus according to 1.
The inverter is composed of bipolar elements,
2. The elevator control device according to claim 1, wherein the protection unit turns off a bipolar element that secures conduction in a direction from the motor toward the bus when the car is emergency stopped. 3.
Monitoring means for monitoring the actual speed of the motor or the car;
With
The device comprises a discharge circuit and a capacitor,
The said protection means selects the thing which interrupts | blocks conduction with the said bus | bath among the said inverter, the said discharge circuit, and the said capacitor according to the actual speed of the said motor or the said car. The elevator control device described.
A detection circuit for detecting a voltage between terminals of the motor is connected between the inverter and the motor. When the voltage between the terminals of the motor is a predetermined value or more, the connection between the inverter and the motor is disconnected. A protection circuit to maintain
The elevator control device according to claim 1, further comprising:
8. The protection circuit according to claim 4, wherein the protection circuit is normally closed without being supplied with electric power, and is opened when electric power is supplied when the car is stopped in an emergency. Elevator control device.