KR200213364Y1 - Inverter overload detection device of elevator - Google Patents

Abstract

The present invention relates to an inverter overload detection device for an elevator, and its configuration is an inverter (hereinafter referred to as " inverter ") which is driven in accordance with an operation command signal from an elevator control panel 30, outputs its operation state to an elevator control panel 30 20, the inverter 20 is set to a default value by the continuous rating X, the overload rating Y, the overload allowable time t ^* , and the sampling time h, (T)) calculated by performing an overload detection program under the control of the control unit 28. The program storage unit 22 stores a program for detecting an overload of the inverter 20 under the control of the control unit 28, A data input unit 26 for inputting data that the user can optionally input in addition to the default value previously stored in the program storage unit 22, Inverter A control unit 28 for performing control on the first half and comparing the calculated output function O (t) with a preset continuous rating and outputting the result; The control unit 28 outputs a failure signal to the elevator control board 30 when the inverter 20 determines that the inverter 20 is driven at a predetermined continuous rating or higher And it is possible to prevent the inverter from being damaged due to overheating.

Description

Inverter overload detection device of elevator

The present invention relates to an inverter overload detecting device for an elevator, and more particularly, to an overload detecting device for an inverter which can detect an overload of an elevator by an input signal from the inverter in connection with an inverter.

1, a general elevator driving apparatus includes a three-phase induction motor 1 driven by AC power of an inverter (not shown), and a three-phase induction motor 1 directly connected to the three- Phase induction motor 1, a brake drum 3 mechanically coupled to the three-phase induction motor 1, and a brake drum 3 mounted opposite to the periphery of the brake drum 3 and having a brake drum 3 A brake shoe 4 for applying a braking force to the brake drum 3 by the force of the spring 5 against the brake drum 3 and a brake 5 for releasing the brake shoe 4 to which the braking force is applied, A direct current power source 7 which supplies a DC power source to the brake coil 6 and a drive circuit which is coupled to the three-phase induction motor 1 through the brake drum 3 and is driven by pulleys The pulley 8 and the driving pulley 8, The brake shoes 3, the brake shoe 4, the springs 5, and the main rope 9 that connects the weight 10 and the elevator car (hereinafter abbreviated as car) 11, The brake coil 6 and the DC power supply 7 are simply called brakes.

According to the general elevator as described above, when the car 11 is stopped, the contact a is opened, the DC power from the DC power source 7 is not energized to the brake coil 6, So that the brake shoe 4 presses the brake drum 6 by the force of the spring 5. Thereafter, when a start command to an arbitrary target layer is issued, the contact a is closed so that the brake coil 6 is operated by the DC power source 7 so that the brake shoe 4 is driven by the brake drum 3 So that the three-phase induction motor 1 starts to rotate by the three-phase alternating-current power supplied from an inverter (not shown) to drive the car 11.

In the conventional elevator as described above, when a load exceeds a reference value, a message is displayed or a warning sound is sounded by detecting a load through a load detecting element provided inside the elevator car.

However, in the conventional elevator as described above, when the elevator is instantly operated in an overloaded state of the inverter which is always supplied with the rated power and the rated power, the overheat of the semiconductor device (not shown) There has been a problem that failure may occur.

The inverter has an algorithm to determine the overload for each inverter manufacturer, but detailed implementation methods are different. In the past, it has been implemented using analog circuits, but digitalization is becoming more and more popular in recent years. Most of the analog circuits are formulated and computed by the control unit. Various algorithms can be developed depending on the computation method, which requires a simple yet reliable algorithm.

The object of the present invention is to provide an inverter overload detection device of an elevator which can prevent the inverter from being damaged due to overheating by judging whether or not the overload is taken into account in consideration of the instantaneous rating in operation of the inverter in the elevator over the rated load .

According to a preferred embodiment of the present invention for achieving the above object, there is provided an inverter which is driven in accordance with an operation command signal from an elevator control panel, outputs its operation state to an elevator control panel and controls driving of the motor, A program for detecting the overload of the inverter under the control of the control section which is set as the default value of the continuous rating X, the overload rating Y, the allowable overload time t ^* and the sampling time h A data storage unit for storing data of an output function calculated by performing an overload detection program under the control of a control unit; and a data storage unit for storing data, And a control unit for controlling the inverter in the inverter, And a control unit for receiving the control signal of the control unit and transmitting the result to the elevator control panel, wherein the control unit controls the inverter to operate at a speed equal to or higher than the continuous rating set by the inverter And outputting a failure signal to the elevator control panel when it is determined that the elevator control unit is in operation.

Fig. 1 is a schematic view showing a general elevator installation structure,

Fig. 2 is a block diagram showing a schematic configuration of an inverter overload detection device of an elevator according to the present invention; Fig.

FIG. 3 is a graph showing characteristics of input and output from an inverter in an inverter overload detecting apparatus of an elevator according to the present invention,

4 is a flowchart showing the operation of the inverter overload detecting device of the elevator according to the present invention.

Description of the Related Art [0002]

20: inverter (motor control section), 22: program storage section,

24: Data storage unit, 26: Data input unit,

28: control unit, 29: interface unit,

30: Elevator control panel.

Hereinafter, an inverter overload detecting apparatus for an elevator according to an embodiment of the present invention will be described in detail.

2 is a block diagram showing the configuration of an inverter overload detecting apparatus of an elevator according to an embodiment of the present invention. As shown in the drawing, reference numeral 20 denotes an inverter for outputting rated AC power, which is also referred to as a motor control section A program storage unit 22 and a data storage unit 24, a data input unit 26, a control unit 28, and an interface unit 29.

The program storage unit 22 is set to a default value by the continuous rating X, the overload rating Y, the overload allowable time t ^* and the sampling time h, A program for performing overload detection of the battery 20 is built in.

The data storage unit 24 stores data calculated by performing an overload detection program under the control of the control unit 28. The data input unit 26 stores the data stored in the program storage unit 22, In addition to the values, the user can optionally input data.

The control unit 28 is installed in the inverter 20 and controls the overall inverter.

The interface unit 29 receives the control signal of the control unit 28 and transmits the control signal.

Reference numeral 30 denotes an elevator control panel that performs overall control of the elevator, and issues an operation command to the inverter 20. The elevator control panel 30 is connected to the interface unit 29 of the inverter 20 via an interface unit 31.

The controller 28 disassembles the transfer function 1 / (1 + Ts) and implements it on the program algorithm to obtain the overload rating characteristic. That is, in the embodiment of the present invention, As shown in FIG.

Further, the transfer function is interpreted as follows, that is,

L {g (t)} = G (s) =

∴ g (t) =

Meanwhile, .

Where t ^{* is the} allowable overload time, X is the overload rating, and Y is the continuous rating.

The G (S) is represented as a slope in the graph, as shown in FIG. 3, which represents the output overload rating. For example, when the overload allowable time t * is 10 seconds, the overload rating X is 200%, and the continuous rating Y is 100%, the output function O (t) As can be seen from FIG. 3, when the output is compared with the continuous rated value after about 10 seconds, the output O (t) becomes larger over the continuous rating toward the overload rating, thereby overloading Is recognized as having occurred.

Meanwhile, O (t) , That is, the method for obtaining the output for the input (i) at the predetermined time t

O (S) = I (S) G (S) = L

∴ O (t) = L ^-1 L Therefore, the output at the set sampling time (h)

Lt; / RTI >

Further, when the sampling time t is two times, the output becomes

Similarly, when O (t = 3h) to O (t = nh) are obtained,

Lt; / RTI >

Also, Can be expressed as

Hereinafter, the operation of the inverter overload detecting device of the elevator according to the present invention will be described with reference to FIG.

First, when an operation command signal from the elevator control panel 30 is input to the control unit 28 via the interface unit 31 and the interface unit 29 of the inverter 20 in the power-on state (step 100) The control unit 28 of the inverter 20 reads the program from the program storage unit 22 and outputs a predetermined default value in response to various parameters such as the continuous rating X, the overload rating Y, The program executes the inverter overload detection program through the reference data such as the time T and the sampling time h (step 102). The control unit 28 always outputs the operating state of the inverter 20 in the current state to the elevator control board 30 (step 104).

Thereafter, the control unit 28 continuously performs the process of determining whether the output O (t) is overloaded during the overload detection program (step 106). If it is determined that the load is not overloaded, the program execution process is continued. If it is determined that the load is overloaded, a fault signal is outputted to the elevator control panel 30 (step 108) And generates an overload detection signal when the output function (O (t)) exceeds the continuous rating.

Thereafter, when it is determined that a fault signal is inputted in accordance with the output signal from the inverter 20, the elevator control unit 30 performs a predetermined function such as stopping the motor or generating an alarm.

As described above, the inverter overload detection device of the elevator according to the present invention can prevent the inverter from being damaged due to overheating by determining the overload state in consideration of the instantaneous rating when the inverter is operated in excess of the rated load, .

In addition, it can be used not only for inverters but also for all applications with momentary rated load above rated load, typically motor control and heating control.

Claims (2)

An inverter (20) which is driven in accordance with an operation command signal from an elevator control panel (30) to output its operation state to an elevator control panel (30) and controls driving of the motor, The inverter (20) Overload of the continuous rating (X), the overload rating (Y), overload permissible time (t ^*), the sampling time (h) an inverter 20, under the control of the controller 28, which will be saved and will be described later as the default (default) value A program storage unit 22 in which a program for detection is embedded, A data storage unit 24 for storing data of the output function O (t) calculated by performing an overload detection program under the control of the control unit 28, A data input unit 26 for allowing a user to arbitrarily input data other than a default value previously stored in the program storage unit 22, A control unit (28) built in the inverter (20) for controlling the overall inverter and comparing the calculated output function (O (t)) with a preset continuous rating and outputting the result, And an interface unit 29 for receiving the control signal of the control unit 28 and transmitting the control signal to the elevator control board 30. If the control unit 28 determines that the inverter 20 is driven at the continuous rated or higher And outputs a failure signal to the elevator control panel (30). 2. The method of claim 1, wherein the output function O (t) O (S) = I (S) G (S) = L ∴ O (t) = L ^-1 L And the transfer function G (S) is obtained through the following process. ≪ tb >< TABLE > L {g (t)} = G (s) = ∴ g (t) = Also, (t ^* : allowable overload time, X: overload rating (%), Y: continuous rating (%)).