WO2016060408A1

WO2016060408A1 - Apparatus for detecting overheating of motor

Info

Publication number: WO2016060408A1
Application number: PCT/KR2015/010627
Authority: WO
Inventors: 이준형
Original assignee: 한국미쓰비시엘리베이터 주식회사
Priority date: 2014-10-13
Filing date: 2015-10-07
Publication date: 2016-04-21
Also published as: KR20160043301A

Abstract

The present invention relates to an apparatus for detecting the overheating of a motor and is a technology which enables accurate detection of the overheating of a motor, even if a temperature sensor is not provided. The present invention comprises: a motor control unit for controlling the driving of a motor; a current detection unit for detecting a current flowing through the motor; a driving unit comprising a motor and a speed detection unit for detecting information on the rotation speed of the motor; a control unit for controlling the operation of the motor control unit in response to a current value detected by the current detection unit and the information on the rotation speed detected by the driving unit; and a power device for supplying a direct current voltage to a winding of the motor.

Description

Motor overheat detection device

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor overheat detection apparatus, and is a technique for accurately detecting overheating of a motor without providing a temperature sensor.

In general, the elevator is provided with a hoist on the upper part of the main frame forming the hoistway, the elevator car is connected to the hoisting rope has a structure that can transport passengers or cargo in the vertical direction.

The elevator, which is operated for rapid movement to the upper or lower floor in the building, moves the elevator car connected to the rope vertically by moving the rope wound on the pulley in the hoist of the machine room installed at the upper part of the building. It's a way of working.

Here, the hoist is a device that drives the elevator car by hanging the hoisting rope and rotating the pulley. The hoisting machine is composed of a motor that provides rotational force, a pulley that suspends the elevator car on a hoisting rope, and moves it up and down, and a brake that stops the rotation of the pulley during operation and stop of the elevator car or maintains a stopped state.

In order to drive an elevator equipped with a hoist, first, the driving means must perform a series of movements such as starting, accelerating, driving, decelerating, stopping and stopping the elevator car by the command of the controller.

On the other hand, the hoisting motor may have a variety of forms according to the operating principle, it is common to wound the winding to generate a torque. Such windings will increase in temperature depending on the amount of operation and load of the elevator. In addition, each motor is divided into insulation grades (Y, A, ㄸ, B, F, H type) according to the increase in temperature.

However, if the motor is overheated above the insulation rating, the insulation may be broken and the motor may fail. Accordingly, the general elevator apparatus is provided with a separate temperature detector for detecting overheating in the inverter unit and the motor.

The temperature detector is preset with a predetermined temperature reference value, and outputs a temperature warning signal when the temperature of the motor reaches the predetermined temperature reference value, and outputs a temperature warning signal when the temperature of the motor is lower than the predetermined temperature reference value. Stop the output. That is, the temperature detector determines whether the temperature warning signal is output by comparing the temperature of the motor with a predetermined temperature reference value.

However, such a temperature detector may have an error in the temperature sensor. That is, most temperature sensors have an error range of ± 5 ° C or more. Accordingly, when the temperature sensor is in the (−) error range, the driving is excessively suppressed, and in the case of the (+) error range, the temperature sensor adversely affects the insulation of the motor.

The temperature sensor can also be attached to the inverter unit or the motor. However, when the temperature sensor is attached to a location where the temperature is low or due to the operator's miss is attached to 1 to 2 centimeters away from the attachment position it is difficult to measure the correct temperature.

In addition, the temperature of the place where the elevator is installed varies depending on the region or season, and thus a nonuniformity caused by the temperature change occurs in the measured value by the temperature sensor. As a result, in order to accurately detect abnormalities, it is necessary to consider the judgment value for each region or season, and the setting requires complicated labor.

The present invention has a feature to accurately detect the overheat of the motor based on the principle that the resistance value of the winding changes in response to temperature without using a temperature sensor.

Motor overheat detection apparatus according to an embodiment of the present invention, the motor control unit for controlling the drive of the motor; A current detector for detecting a current flowing in the motor; A driving unit including a motor and a speed detecting unit detecting rotational speed information of the motor; A controller which controls the operation of the motor controller in response to the current value detected by the current detector and the rotational speed information detected by the driver; And a power supply for supplying a DC voltage to the winding of the motor.

The present invention provides the effect of being able to accurately detect overheating of the motor without using a temperature sensor.

In addition, the embodiments of the present invention are intended to illustrate, various modifications, changes, replacements and additions will be possible to those skilled in the art through the spirit and scope of the appended claims, such modifications and modifications belong to the following claims Should be seen.

1 is a block diagram of a motor overheat detection apparatus according to an embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings will be described in detail an embodiment of the present invention.

1 is a block diagram of a motor overheat detection apparatus according to an embodiment of the present invention. Motor overheat detection device according to an embodiment of the present invention can be applied to any device equipped with a motor. For example, the motor overheat detection apparatus according to the embodiment of the present invention may be applied to a simple resistance tester, an elevator hoisting motor, and the like. In the embodiment of the present invention will be described as an example that the motor overheat detection device is applied to the hoisting motor for an elevator.

An embodiment of the present invention includes a power supply unit 100, an inductor 110, a motor control unit 200, a current detector 300, a driving unit 400, a control unit 500, and a power supply unit 600.

Here, the motor controller 200 includes a converter 210, a condenser 220, and an inverter 230. The driver 400 includes a motor 410 and a speed detector 420. The controller 500 includes an inverter driver 510, an inverter controller 520, and a driving controller 530.

The power supply unit 100 receives power from a commercial power source and supplies power to the motor control unit 200 through an electrically openable switch. Here, the power supplied from the power supply unit 100 may be a three-phase AC power. The inductor 110 suppresses a sudden change in the current applied from the power supply unit 100 to supply the motor control unit 200.

The motor controller 200 applies driving power to the driver 400 through a high speed switching operation. Here, the power applied from the motor control unit 200 may be three-phase AC power.

To this end, the converter 210 converts an AC voltage applied from the power supply unit 100 into a DC voltage. The capacitor 220 is connected between the converter 210 and the inverter 230. Here, the capacitor 220 smoothes the pulsating DC voltage applied from the converter 210.

The motor control unit 200 includes an inverter 230. The inverter 230 uses a power conversion element such as an Insulated Gate Bipolar Transistor (IGBT), an Intelligent Power Module (IPM), or the like.

The inverter 230 generates an alternating current having an arbitrary voltage and frequency that is varied by switching a DC voltage generated by the converter 210 and supplies the alternating current to the motor 410. That is, the inverter 230 adjusts the output voltage by pulse width modulation (PWM) by generating a plurality of DC voltage pulses within the fundamental frequency of the AC current.

At this time, the output voltage of the inverter 230 is controlled by adjusting the switching duty ratio. Accordingly, the motor 410 is variable speed driven by the output voltage applied from the inverter 230.

The current detector 300 detects a current flowing in the motor 410 from the output terminal of the inverter 230. Here, the current detector 300 may detect the value of the motor current supplied from the motor controller 200 to the motor 410 by a CT (Current Transformer).

The motor 410 moves up and down the car by the electric power applied from the motor control unit 200. Here, the motor 410 may be made of a permanent magnet motor. The motor 410 is operated by receiving driving power from the motor controller 200. The speed detector 420 detects the rotation speed of the drive sheave connected to the motor 410.

The controller 500 controls the motor controller 200 based on the current value detected by the current detector 300 and the rotation speed information (speed value of the motor and rotor angle value) of the motor 410 detected by the speed detector 420. To control the operation.

Here, the inverter controller 520 receives the current value detected by the current detector 300, the rotation speed value of the motor detected by the speed detector 420, and the rotor angle value, and outputs them to the inverter driver 510. do. That is, the inverter controller 520 calculates a torque value to match the rotational speed of the motor 410 with the speed command value based on the information such as the speed value and the rotor angle detected by the speed detector 420. And output to the inverter driver 510.

For example, the inverter controller 520 converts the torque value applied from the speed detector 420 into a current value to obtain a target current value of the motor 410, and the motor 410 detected by the current detector 300. The driving of the inverter driver 510 is controlled so that the current value of the coincides with the target current value.

In addition, the inverter driver 510 controls the driving of the inverter 230 based on the value applied from the inverter controller 520.

In addition, the driving control unit 530 creates driving management information (for example, the destination floor of the car, the information of the driving command, etc.) for the operation of the elevator based on the car operation signal and the boarding point operation signal. The driving controller 530 outputs a signal for controlling the speed of the car to the inverter controller 520 based on the driving management information.

If the load balance between the car and the counterweight is unbalanced for a long time or driven for a long time with a high acceleration / deceleration or speed, the temperature of the motor 410 rises.

In the embodiment of the present invention, without the temperature sensor is physically attached to the inverter 230 or the motor 410, the temperature value is measured based on the principle that the winding resistance value of the motor 410 changes linearly in response to the temperature. Do it. In this case, the temperature can be measured more precisely than the method of measuring the temperature by attaching an actual temperature sensor.

To this end, the power supply 600 supplies a DC voltage to the winding of the motor 410. Then, the winding resistance value of the motor 410 may be measured as shown in Equation 1 according to the temperature.

[Equation]

Winding resistance value = (234.5 + θ) / (234.5 + 20) * 20 ℃

In Equation 1, θ represents a temperature value. And the number of 234.5 represents the constant of copper. Copper wires are often used as conductor wires such as coils, lead wires, and connecting wires. The winding of the motor 410 may also be made of copper, where a constant value of copper corresponds to 234.5. In addition, the constant 20 shows the reference temperature value of 20 degreeC at normal temperature.

For example, the inverter controller 520 programs the resistance value of the motor 410 at the reference temperature (20 ° C.) in advance in the storage unit 521. In the exemplary embodiment of the present invention, the storage unit 521 is included in the inverter controller 520 as an example. However, the embodiment of the present invention is not limited thereto, and the storage unit 521 may be included in the driving control unit 530.

Then, a DC voltage is applied to the motor 410 through a separate power supply device 600. Here, the power supply device 600 is connected to a separate blocking control unit 610 therein.

Accordingly, the power supply device 600 is blocked in the normal mode and the driving of the motor 410, the blocking control unit 610 is cut off does not apply a DC voltage to the motor 410. On the other hand, in the power supply device 600, the blocking control unit 610 is short-circuited for a predetermined time (for example, within 1 second) only while the motor 410 is stopped to supply a DC voltage to the motor 410. .

The L component (unit mH) of the motor 410 is invalidated by the DC voltage supplied from the power supply 600, and a current corresponding to pure resistance flows through the winding of the motor 410. The current flowing through the winding of the motor 410 is measured through the current measuring unit 300, and the measured current value is transmitted to the inverter controller 520.

The inverter controller 520 determines the winding resistance value of the motor 410 using the principle of V = IR. Here, V represents the value of the DC voltage supplied by the power supply device 600, I represents the current value detected by the current measuring unit 300. Accordingly, the winding resistance value of the motor 410 may be determined by applying the voltage V and the current I values.

The inverter controller 520 may determine the winding resistance value of the motor 410 and check the temperature θ based on Equation 1 above. In addition, the inverter controller 520 determines how many degrees Celsius the temperature in the current driving state corresponds to the confirmed temperature θ.

In addition, the inverter controller 520 compares the determined temperature θ with the insulation level of the motor 410 to determine whether the motor 410 is overheated. Here, the insulation grade of the motor 410 as a reference is pre-stored in the storage unit 521.

Then, the inverter driver 510 controls the switching operation of the inverter 230 in response to the measured temperature θ value. That is, the inverter driver 510 controls the inverter 230 to accelerate or stop the motor 410 depending on whether the temperature θ measured by the inverter controller 520 is overheated or not.

For example, the inverter driver 510 controls the inverter 230 to stop or reduce the rotation of the motor 410 according to the control of the inverter controller 520 when the detected temperature θ is overheated. On the other hand, the inverter driver 510 controls the inverter 230 to operate or speed up the motor 410 as it is under the control of the inverter controller 520 when the detected temperature θ is not overheated.

It should be understood that the exemplary embodiments described above are exemplary in all respects and not restrictive. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined form.

Claims

A motor controller for controlling driving of the motor;

A current detector for detecting a current flowing in the motor;

A driving unit including the motor and a speed detecting unit detecting rotational speed information of the motor;

A controller which controls an operation of the motor controller in response to the current value detected by the current detector and the rotation speed information detected by the driver; And

And a power supply device for supplying a DC voltage to the winding of the motor.
The method of claim 1, wherein the motor control unit

A converter for converting an AC voltage applied from a power supply unit into a DC voltage;

A capacitor for smoothing the output voltage of the converter; And

And an inverter for supplying a driving current to the motor in response to the DC voltage.
The motor overheat detection apparatus of claim 1, wherein the rotation speed information includes a rotation speed of the motor and a rotor angle.
The method of claim 1, wherein the control unit

An inverter driver for controlling driving of the motor controller; And

An inverter controller which controls an operation of the inverter driver in response to the current value detected by the current detector and the rotation speed information; And

And a driving controller configured to store driving management information on driving of the motor and to output a control signal corresponding to the driving management information to the inverter controller.
The method of claim 4, wherein the inverter control unit

The temperature value is expressed by the formula of [the winding resistance value of the motor = (constant copper value + θ) / (constant copper value + constant value corresponding to reference temperature at room temperature) * motor resistance at reference temperature]. Motor overheat detection device, characterized in that the operation.
The method of claim 5, wherein the inverter control unit

And a winding resistance value of the motor in response to the DC voltage supplied from the power supply device and the current value detected by the current detection unit.
The apparatus of claim 5, wherein the inverter controller further comprises a storage unit which pre-stores a motor resistance value at the reference temperature.
6. The motor overheat detection apparatus according to claim 5, wherein the inverter controller determines whether the motor is overheated by comparing the detected shock temperature with the insulation level of the motor.
The motor overheat detection apparatus according to claim 1, further comprising a power supply unit receiving power from a commercial power source and supplying power to the motor control unit.
The method of claim 1, wherein the current detection unit

And a CT (Current Transformer) for detecting a value of the current supplied from the motor control unit to the motor.
The method of claim 1, wherein the power supply unit

And a cut-off control unit which cuts off the supply of the DC voltage when the motor is driven and controls to supply the DC voltage for a predetermined time when the motor is stopped.