KR200252917Y1 - Magnetic brake controller using thyristors - Google Patents

Abstract

The present invention relates to a magnetic brake control device for braking a driving power shaft using a magnetic circuit. The brake control device of the present invention includes a brake for braking a driving power shaft; A thyristor switch circuit for providing a voltage rectified by the thyristor to the brake by driving two pairs of thyristors connected in a bridge form to an AC power supply line according to a thyristor switch control signal; A thyristor driver for turning on and off each pair of thyristors in the thyristor switch according to a firing angle control signal; A current sensor disposed on a supply line of the AC power source and measuring a brake current provided to the brake; A voltage detector disposed at both ends of the AC power source and detecting a switching voltage applied across the thyristor switch; And a control means for outputting a firing angle control signal required for the silist driver by using the power current measured by the current sensor and the voltage detected by the voltage detector according to the drive current value provided to the brake.

Therefore, by implementing the brake control device using the thyristor, it is possible to prevent damage due to mechanical wear as in the prior art.

Description

Magnetic brake control device using thyristors {MAGNETIC BRAKE CONTROLLER USING THYRISTORS}

The present invention relates to a magnetic brake control device for braking a driving power shaft using a magnetic circuit, and more particularly, to a magnetic brake control device using a thyrister.

As is well known in the art, magnetic brake devices are effectively used to brake such power shafts in rolling mills, cranes, machine tools, etc., which have power shafts that rotate or drive. The magnetic brake system operates by applying current to a winding wound on one side of a pair of brake iron pieces which face each other with a power shaft therebetween, so as to magnetize the iron pieces wound on the winding side to pull the iron pieces on the other side.

Typically, the magnetic brake device controls the brake with strong field current to ensure fast response only during the initial operation of the brake, and when the operation is stable, the brake state is controlled with a weak field current. It is to be controlled to maintain it, and when the brake is closed, a reverse voltage should be generated to quickly remove the energy stored in the brake magnet. In other words, when the brake is opened, a large amount of current must be provided to the coil so as to overcome the magnetoresistance generated from the iron pieces on both sides, and after a certain time, the brake is stabilized and the magnetoresistance decreases significantly. In order to protect the winding, it controls to reduce the current flowing in the winding.

Prior art magnetic brake control devices provide current to the windings in a switching manner using a relay. That is, the relay contact is opened and closed each time the brake is opened and closed to provide the winding with the strong magnetic current, the weak magnetic flux current, and the brake reverse voltage. However, the mechanical switching method using a relay has a problem in that the damage and wear of the contact proceeds every time the opening and closing is made, thereby shortening its lifespan.

In addition, the magnetic brake control apparatus of the prior art has a configuration that consumes energy by using an element such as a resistor on the load side in order to release the energy stored in the brake magnet when the brake is closed. Because of this, the energy stored in the brake magnet is not quickly exhausted, there is a problem that leads to an increase in components.

Therefore, an object of the present invention is to provide a magnetic brake control device capable of preventing mechanical damage by using a thyristor as a switching contact.

A magnetic brake control apparatus according to the present invention for achieving the above object comprises: a brake for braking a driving power shaft; A thyristor switch having two pairs of thyristors connected in a bridge form to an AC power supply line and driving the pair of thyristors according to a thyristor switch control signal to turn on and off the pair of thyristors to provide the voltage rectified by the thyristor to the brake; Circuit; A thyristor driver for controlling a current applied to the brake by turning on and off each pair of thyristors in the thyristor switch according to a firing angle control signal; A current sensor disposed on a supply line of the AC power supply and measuring a power supply current provided to the brake; A voltage detector disposed at both ends of the AC power source and detecting a switching voltage applied across the thyristor switch; A firing angle control signal required for the thyrist driver is obtained by using the power current measured by the current sensor and the voltage detected by the voltage detector according to the strong magnetic flux holding current value or the weak magnetic flux holding current value provided to the brake. And control means for outputting.

In addition, the control means according to the present invention includes: a current command value generating unit for generating a current command value corresponding to the drive current value; A voltage / current control unit generating a firing angle signal for controlling a current applied to the brake by adjusting a power supply current detected by the current sensor according to the current command value provided by the current command value generation unit; And a driving signal generator for generating the firing angle control signal by controlling the phase of the switching voltage provided from the voltage detector according to the firing angle signal provided from the voltage / current controller.

1 is a block diagram of a magnetic brake control device constructed according to the present invention,

FIG. 2 is a detailed circuit diagram of each component shown in FIG. 1;

3 is a detailed block diagram of the controller shown in FIG. 1;

FIG. 4 is a diagram illustrating waveforms occurring in each configuration shown in FIG. 1. FIG.

<Description of the symbols for the main parts of the drawings>

100: magnetic brake 120: current sensor

130: voltage detector 150: thyristor switch

160: thyristor driver 200: controller

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

1 is a schematic block diagram of a brake control apparatus using a thyristor according to the present invention, a magnetic brake 100, a strong magnetic flux holding time setting unit 112, a weak magnetic flux current setting unit 114, generating a brake closing command The unit 116 includes a current sensor 120, a voltage detector 130, a thyristor switch 150, a thyristor driver 160, and a controller 200.

The magnetic brake 100 is composed of a magnetic brake that brakes the driving shaft (not shown) by using a magnetic circuit as described above.

The strong magnetic flux holding time setting unit 112 sets a current initially provided to the brake 100 as a current value SF_TIME generated by changing the position of the variable resistor. Similarly, the weak magnetic flux current setting unit 114 is variable. By changing the position of the resistor, the current value WF_CUR for maintaining the operation of the brake 100 is set. The current values set by the strong magnetic flux holding time setting unit 112 and the weak magnetic flux current setting unit 114, that is, (SF_TIME) and (WF_CUR), are provided to the controller 200.

Meanwhile, the brake close command generation unit 116 generates a logic high or logic low signal when the brake 100 is turned off by the user and provides the break off command signal to the controller 200.

The current sensor 120 having the configuration as shown in detail in FIG. 2A is disposed on one side of the supply line of the AC power source 110, and the power supply current IS provided to the magnetic brake 100 (see FIG. 4). Is measured and provided to the controller 200.

The voltage detector 130 having a configuration as illustrated in detail in FIG. 2B is disposed at both ends A and B of the AC power source 110 to detect a voltage applied to both ends of the thyristor switch 150. The voltage detector 130 detects the phase of the AC power supply 110 and provides the switching voltage signal RBD (see FIG. 4) of the detected phase to the controller 200.

The thyristor switch circuit 150 has two pairs of thyristors 152, 154; 156, 158 connected in a bridge form to the supply line of the AC power source 110, and is provided with 180 ° provided from the thyristor driver 160 described below. Two pairs of phase shifted thyristor switch control signals ; Drive accordingly to provide a full wave rectified voltage to the brake 100.

As illustrated in detail in FIG. 2C, the thyristor driver 160 generates a pair of thyristors 152 in the thyristor switch circuit 150 according to firing angle control signals G1 and G2 output from the controller 200. 154: controls the current applied to the brake 100 by turning on and off the 156 and 158.

The controller 200 includes a strong magnetic flux holding time SF_TIME, a weak magnetic flux current WF_CUR and a brake closing signal OFF, a power current IS measured by the current sensor 120, and a voltage detector (set by the user). The voltage value RBD of 130 is applied, and it operates as a means for outputting the firing angle control signals G1 and G2 necessary for the thyrist driver 160. Such a controller can be implemented as a microcontroller called PIC16C73.

Referring to FIG. 3, a detailed block diagram of the controller 200 includes a current command value generator 210, a voltage / current controller 220, and a driving signal generator 230.

The current command value generator 210 generates a current command value converted into a digital signal corresponding to the strong magnetic flux holding time SF_TIME and the weak magnetic flux current WF_CUR to generate a current command value. To provide.

The voltage / current control unit 220 is a power source detected by the current sensor 120 in accordance with the current command value corresponding to the strong magnetic flux holding time (SF_TIME) and the weak magnetic flux current (WF_CUR) provided by the current command value generator 210 By regulating the current IS (see FIG. 4), a firing angle is generated that controls the current and voltage applied to the brake. In the power supply voltage illustrated in FIG. 4, the positive pulse means a cycle of turning on the thyristor pairs 152 and 154 in the forward direction, and the negative pulse means a cycle of turning on the thyristor pairs 156 and 158 in the reverse direction. Zero-crossing of each positive or negative pulse represents the trigger point (point) at which the thyristors 152, 154 or thyristors 156, 158 are turned on, and the distance (α) delayed from the trigger point is called the firing angle. do. The voltage / current control unit 200 generates a firing angle according to the strong magnetic flux holding time SF_TIME and the weak magnetic flux current WF_CUR provided from the current command value generator 210, and the generated firing angle is the driving signal generator. Is output to 230.

In addition, the voltage / current controller 220 generates a firing angle for generating a reverse voltage for sacrificing energy stored in the brake as a power source when receiving the brake closing brake closing signal command (OFF). The firing angle generated by the voltage current / control unit 220 is provided to the driving signal generator 230.

The driving signal generator 230 uses the firing angle signal provided from the voltage / current control unit 220 and the switching voltage RBD provided from the voltage detector 130. G2) is generated and provided to the thyristor driver 160.

The thyristor driver 160 has a switch control signal (output) at its output in accordance with the firing angle control signals G1 and G2. ; ) Is provided to the thyristors 152, 154; 156, 158 in the thyristor switch 150. At this time, the switch control signal generated by the firing angle control signal (G1, G2) ( Is applied to the thyristors 152 and 154, current flows in the order of the thyristor 152, the brake 100, the thyristor 154, and the current sensor 120, and vice versa. ) Is provided to the thyristors 156 and 158, the thyristor 156, the brake 160, the thyristor 158, and the current sensor 120 flow in order. Therefore, the brake 100 operates according to the current value set by the strong magnetic flux holding time setting unit 112 and the weak magnetic flux current setting unit 114.

On the contrary, in the case where the break-off command OFF is set by the break-off setting unit 116, the brake angle control signals opposite to the above-mentioned firing-angle control signals G1 and G2 are generated from the controller 200, thereby causing the brake. A large reverse voltage is generated in the 100, so that the energy stored in the brake 100 flows to the AC power source 110 through the thyristors 152, 154, 156, and 158.

Therefore, by implementing the brake control device using the thyristor according to the present invention, there is an effect that can prevent damage due to mechanical wear as in the prior art.

Claims (2)

In the magnetic brake control device, A brake 100 for braking a driving power shaft; Two pairs of thyristors 152, 154, 156, 158 connected in a bridge form to the supply line of the AC power supply 110, and provided with two pairs of thyristor switch control signals 180 ° phase shifted from the thyristor driver 160 ; A thyristor switch circuit 150 that is controlled by being driven according to and provides a voltage rectified by the thyristor to the brake 100; Current applied to the brake 100 by turning on and off each pair of thyristors 152, 154, 156, and 158 in the thyristor switch 150 in accordance with a firing angle control signal G1, G2. Thyristor driver 160 for controlling the; A current sensor (120) disposed on a supply line of the AC power source (110) for measuring a power current provided to the brake (100); A voltage detector (130) disposed at both ends of an AC power source (110) for detecting a switching voltage applied across the thyristor switch (150); The silist driver 160 using the power supply current IS measured by the current sensor 120 and the switching voltage RBD detected by the voltage detector 130 according to the driving current value provided to the brake. And control means for outputting a firing angle control signal (G1, G2) required for the magnetic brake control device. The method of claim 1 wherein the control means: A current command value generator 210 generating a current command value corresponding to the brake drive current value; A voltage for generating a firing angle signal for controlling the current applied to the brake by adjusting the power supply current (IS) detected by the current sensor 120 according to the current command value provided by the current command value generator 210. / Current controller 220; A driving signal generator for generating the firing angle control signals G1 and G2 by controlling the phase of the switching voltage RBD provided from the voltage detector 130 according to the firing angle signal provided from the voltage / current controller 220. 230, characterized in that Magnetic brake control device.