KR200361334Y1 - Electron induction heating device - Google Patents

Abstract

The present invention; The present invention relates to an electromagnetic induction heating device that can prevent damage to internal components including expensive IGBTs when using a plurality of IGBTs.

The present invention as such; A button unit 10; A rectifier 20 for converting an AC voltage into a DC high frequency voltage; A current detector 30 detecting a current consumption; A first stabilizer 40 which outputs an error holding signal when an overcurrent is detected; A microcomputer 60 outputting the same two reference frequencies OSC1 and OSC2 with a delay time DT and suspending the IGBT driving pulse supply operation when an arm short or overcurrent is detected; An IGBT driving pulse oscillator 70 generating the IGBT oscillation frequencies A and B through the reference frequencies OSC1 and OSC2; A heating unit 80 supplying a current to the working coil by alternately turning on a plurality of IGBTs according to two IGBT oscillation frequencies A and B; A second stabilizer 90 for notifying the microcomputer 60 of the arm short of the heating unit 80 or the excessive resonant current phenomenon; A power supply unit 100 supplying power to each block; And a display unit 110 for displaying an internal state and an error state of the system.

According to the present invention; Internal components, including expensive IGBTs, are not damaged, resulting in stabilization of the system while reducing economic losses.

Description

Electromagnetic Induction Heating Equipment {ELECTRON INDUCTION HEATING DEVICE}

The present invention relates to an electromagnetic induction heating apparatus, and more particularly, to prevent damage to internal parts including expensive IGBTs in a heater using a plurality of Insulated Gate Bypolar Trnasistor (hereinafter referred to as "IGBT"). It relates to an electromagnetic induction heating device that allows.

As is well known, the electromagnetic induction heating apparatus, which is rapidly developing recently, requires a large capacity IGBT because a large amount of current must be supplied to the working coil due to the device characteristics. In addition, two or more IGBTs are applied to the electromagnetic induction heater to supply a large amount of current to the working coil more efficiently.

However, the electromagnetic induction heaters using a plurality of IGBTs on the market use a different reference frequency in generating driving pulses for driving the plurality of IGBTs, and therefore, a period of any one reference frequency due to noise. When the IGBT fluctuates, a plurality of IGBTs are turned on at the same time, which causes expensive IGBTs to be destroyed frequently.

In addition, conventional electromagnetic induction heaters include arm shorts, short working coils, or shorts between heat sinks that occur frequently during the operation of an operator, overpower (overcurrent or overvoltage) inflow of power input terminals, and devices. Since there was no function to detect and cope with overheating due to the sudden rise of the internal temperature, the parts including expensive IGBTs were frequently damaged, which caused not only economic loss but also consumer dissatisfaction. There was this.

In addition, the conventional electromagnetic induction heating device has no function of displaying the current state and error conditions of the device to the operator, the operator can not accurately grasp the current status of the heating device, which is difficult to install and maintain there was.

Accordingly, the present invention has been made to solve the conventional problems as described above, and an object of the present invention is to generate by using the same reference frequency having only a constant delay time in generating drive pulses for driving a plurality of IGBTs. In addition, the present invention provides an induction heating device for eliminating the phenomenon of a plurality of IGBTs turning on at the same time.

For other purposes, the working coil short or heat sink short occurs frequently during operation of the operator, over current inflow at the power input terminal, surge occurs due to unstable power terminal contact, and overheating due to a sudden rise in the internal temperature of the device. The system automatically stops a plurality of IGBTs as a countermeasure, and eliminates the damage of parts including expensive IGBTs, and also prevents the IGBT temperature rise through current control after detecting the current rise. By protecting the IGBT, the present invention provides an induction heating device to reduce the economic loss of the operator and the consumer.

Another purpose is to add a function that accurately informs the operator of the current operating status and error conditions of the heating device, allowing the operator to quickly identify the current status and error conditions of the heating device, thereby facilitating easy installation and It is to provide an electromagnetic induction heating device for maintenance work.

In order to achieve the above object, the present invention electromagnetic induction heating apparatus, in the electromagnetic induction heating apparatus having a plurality of IGBT (large capacity TR),

A button unit including a start button and a state check button;

A rectifier for converting a commercial AC input voltage into a DC high frequency voltage;

A current detector for detecting a current consumption of the rectifier;

A first stabilizer outputting an error holding signal when an overcurrent is detected from the current sensing unit;

When the start button is turned on, the same two reference frequencies OSC1 and OSC2 are output with a delay time DT, respectively. If the current consumption value detected by the current sensing unit is greater than the reference value, the two reference frequencies are corresponding to each other. When the error holding signal or the arm short error signal is input, the reset signal in the low state is output high and the error holding control signal is output. A microcomputer that automatically outputs a reset signal again when a predetermined time elapses and releases the error holding control signal;

After receiving two reference frequencies OSC1 and OSC2 having a delay time DT from the micom, respectively, two IGBT oscillation frequencies A and B are generated through a predetermined logic operation, but are high from the micom. An IGBT driving pulse oscillator for stopping the frequency oscillation operation when the reset signal and the error holding control signal are inputted;

As the two IGBT oscillation frequencies A and B are received from the IGBT driving pulse oscillator, the two IGBTs are alternately turned on at predetermined intervals t to alternately supply the high frequency voltage to the working coil. A heating unit;

A second stabilizer for detecting an arm short in two IGBTs of the heating unit and outputting an arm short error signal to the microcomputer;

A power supply unit supplying power to each block;

A display unit configured to display an internal state and an error state of a system to an operator under the control of the microcomputer; And

It is characterized by consisting of a bimetal for detecting overheating of the heat sink.

1 is a functional block diagram showing the internal configuration of the electromagnetic induction heating apparatus according to an embodiment of the present invention,

Figure 2 is a functional block diagram showing the internal configuration of the first stabilizer in the electromagnetic induction heating device according to Figure 1,

Figure 3 is a functional block diagram showing the internal configuration of the second stabilizer in the electromagnetic induction heating device according to Figure 1,

4 is a waveform diagram of each part of FIG. 1;

5 is an operation flowchart showing a control method of the electromagnetic induction heating apparatus according to an embodiment of the present invention.

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

10: button portion 20: rectification portion

30: current sensing unit 40: buffer

50: first stabilizer 60: microcomputer

70: IGBT driving pulse oscillation unit 80: heating unit

90: second stabilizer 100: power supply

110: display unit 120: temperature sensor

130: bimetal

Hereinafter, an electromagnetic induction heating apparatus according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a functional block diagram of an electromagnetic induction heating apparatus according to an embodiment of the present invention, the electromagnetic induction heating apparatus according to an embodiment of the present invention is a button unit 10, rectifier 20, current sensing unit 30 ), Buffer 40, first stabilizer 50, micom (60), IGBT drive pulse oscillator 70, heating unit 80, second stabilizer 90, power supply unit 100 , A display unit 110, a temperature sensor 120, and a bimetal 130.

The button unit 10 includes a start button 11 and a state check button 12.

The rectifier 20 may further include a line filter 21 for filtering a commercial alternating current (AC) input voltage and a DC input voltage filtered through the line filter 21. Direct Current) AC / DC rectifier 22 for converting to a high frequency voltage, coil (L1) and the capacitor (C1) consisting of filtering the DC high frequency voltage rectified through the AC / DC rectifier 22 and the heating unit It consists of the high frequency filter part 23 supplied to 80.

In addition, the current detector 30 detects a current consumption of the rectifier 20 through the current transformer CT1 and outputs the current to the buffer 40.

In addition, the buffer 40 is installed between the current sensing unit 30 and the microcomputer 60, and after filtering the current consumption value detected by the current sensing unit 30 to stabilize the voltage fluctuations. It serves to supply to the microcomputer (60).

Meanwhile, the first stabilizer 50 outputs an error holding signal to the microcomputer 60 when an overcurrent is detected from the current detector 30, and a surge voltage detector as shown in FIG. 2. It consists of 51, the rectifier 52, zener diode ZD1, and comparator 53. As shown in FIG.

At this time, the surge voltage detection unit 51 of the first stabilizer 50 serves to output the surge voltage to the rectifier 52 when the surge voltage is detected from the current detection unit 30. In addition, the rectifier 52 receives a surge voltage from the surge voltage detecting unit 51 and converts the surge voltage into a DC voltage. At this time, the zener diode ZD1 is connected to the rectifier 52 to protect the comparator 53 by limiting the input voltage not to be higher than the supply voltage of the comparator 53. In addition, the comparator 53 compares the surge voltage rectified through the rectifier 52 with the 5V reference voltage to determine whether there is an overcurrent, and if it is determined to be an overcurrent, outputs an error holding signal to the microcomputer 60. do.

Meanwhile, when the start button 11 is turned on, the microcomputer 60 sets the same two reference frequencies OSC1 and OSC2 as shown in FIG. 4 with a delay time DT, respectively. And outputs by adjusting up and down the two reference frequencies OSC1 and OSC2 so that the current consumption value detected by the current sensing unit 30 is greater than the reference value. When the error holding signal or the arm short error signal is received from the (50, 90), the reset signal in the low state along with the error holding control signal is converted to high and output to the IGBT driving pulse oscillator 70, respectively. The IGBT driving pulse oscillator 70 is stopped, and when a predetermined time (about 30 seconds) elapses, the IGBT driving pulse is automatically outputted again as a low reset signal and the error holding control signal is released. Restart the Oscillator 70 Key acts. At this time, the two reference frequencies (OSC1, OSC2) means a frequency of "23 kHz" can be changed, the delay time (Delay Time) between the two reference frequencies (OSC1, OSC2) is "2 to 5 kHz" "to be. Here, the method of setting the current consumption reference value by the microcomputer 60 is a time point when oscillation of the reference frequencies OSC1 and OSC2 ends after the start button 11 is turned on, that is, when the reference frequency becomes “23 kHz”. Check the current consumption value at and set it as the reference value.

In addition, if the internal temperature of the device measured by the temperature sensor 120 is greater than or equal to the reference temperature value, the microcomputer 60 converts the reset signal in a low state into high to drive the IGBT driving pulse. By outputting to the oscillator 70, it serves to stop the driving of the IGBT driving pulse oscillator 70.

In addition, when the state check button 12 is continuously turned on, the microcomputer 60 performs a control operation to display an internal state and an error state of the system to the operator accordingly.

On the other hand, the IGBT driving pulse oscillator 70 receives two reference frequencies OSC1 and OSC2 having a delay time DT from the microcomputer 60 and receives two IGBT oscillation frequencies through a predetermined logical operation. A and B are generated and then supplied to the heating unit 80. As shown in FIG. 1, the first IC operation unit 71, the second IC operation unit 72, the transistor Q1, and the first operation unit are provided. A first NAND gate 73, a second NAND gate 74, a third IC calculating section 75, a fourth IC calculating section 76, and an OR gate 77 are formed.

At this time, the first IC calculating unit 71 of the IGBT driving pulse oscillator 70 receives the first reference frequency OSC1 from the microcomputer 60 and then outputs the first reference frequency OSC1 to the output terminal a. On the other hand, the b output terminal serves to invert and output the first reference frequency OSC1.

In addition, the second IC calculating unit 72 of the IGBT driving pulse oscillator 70 receives the second reference frequency OSC2 from the microcomputer 60 and then outputs the second reference frequency OSC2 to the c output terminal as it is. On the other hand, the output terminal d inverts and outputs the second reference frequency OSC2.

In addition, the transistor Q1 of the IGBT driving pulse oscillator 70 has a base terminal connected to a reset output terminal of the microcomputer 60, an emitter terminal grounded, and a collector terminal connected to a 5V power input terminal. Turn-on when the reset signal is received from the high state.

In addition, the first NAND gate 73 of the IGBT driving pulse oscillator 70 has an input terminal of each of the a and c output terminals of the first and second IC operation units 71 and 72, a 5V power input terminal, and the transistor Q1. Is connected to a collector terminal of the first and second IC operation units 71 and 72 and receives the first and second reference frequencies OSC1 and OSC2 from the a and c output terminals, and performs a NAND operation on the fourth IC. While outputting to the operation unit 76, when the error holding control signal is input from the microcomputer 60, the 5V power is cut off, and the transistor Q1 is turned on, the operation is stopped to prevent IGBT damage.

On the other hand, the second NAND gate 74 of the IGBT driving pulse oscillator 70, each input terminal is a b, d output terminal of the first, second IC operation unit 71, 72, a 5V power input terminal and the transistor Q1. First and second reference frequencies connected to the collector terminals of the first and second IC operation units 71 and 72 and , ) Is input to the third IC operation unit 75 by NAND operation, and when the error holding control signal is input from the microcomputer 60, 5V power is cut off and the transistor Q1 When turned on, operation stops and prevents IGBT damage.

In addition, the third IC calculator 75 of the IGBT driving pulse oscillator 70 inverts the output frequency of the second NAND gate 74 and then applies the first IGBT oscillation frequency A as shown in FIG. 4 to the heating unit. It serves as a supply to (80).

In addition, the fourth IC calculating unit 76 of the IGBT driving pulse oscillator 70 inverts the output frequency of the first NAND gate 73 and then applies the second IGBT oscillation frequency B as shown in FIG. 4 to the heating unit. It serves as a supply to (80).

In addition, the OR gate 77 of the IGBT driving pulse oscillator 70 has an e input terminal connected to a reset output terminal of the microcomputer 60, an f input terminal is grounded, and a g output terminal is the first to fourth IC calculating units. Connected to an input terminal of (71, 72, 75, 76), and outputs a high signal to the first to fourth IC calculation units (71, 72, 75, 76) when the reset signal of the microcomputer (60) is low; After driving, when the reset signal of the microcomputer 60 changes to a high state, a low signal is output to a g output terminal to stop all operations of the first to fourth IC operations 71, 72, 75, and 76. .

Meanwhile, the heating unit 80 receives the two IGBT oscillation frequencies A and B as shown in FIG. 4 from the IGBT driving pulse oscillation unit 70 at predetermined intervals t, and thus, the two IGBTs 84. Alternately turn on, and alternately supply the high frequency voltage of the rectifier 20 to the working coil 86. The first IGBT driver 81 and the second IGBT as shown in FIG. It consists of the drive part 82, the 1st, 2nd resonant capacitors Cr1 and Cr2, and the fan 83. As shown in FIG.

At this time, the first IGBT driver 81 of the heating unit 80 turns on / off the first IGBT 84 according to the first oscillation frequency A output from the IGBT drive pulse oscillator 70. Play a role. In addition, the second IGBT driver 82 turns on / off the second IGBT 85 according to the second oscillation frequency B output from the IGBT drive pulse oscillator 70, and the first IGBT 84. ) And a predetermined interval (t) alternately turn on / off. The first and second resonant capacitors Cr1 and Cr2 are connected in parallel with the first and second IGBTs 84 and 85 with the working coils 86 interposed therebetween as shown in FIG. In addition, the fan 83 is installed in a heat sink (IGBT heat sink), not shown, to switch on / off under the control of the switch SW1 of the microcomputer 60 to cool internal heat.

Meanwhile, the second stabilizer 90 detects an arm short or excessive resonant current in two IGBTs 84 and 85 of the heating unit 80 to detect an arm short error signal to the microcomputer 60. As shown in FIG. 3, it is composed of a rectifier 91, a zener diode ZD2, a comparator 92, and a photocoupler 93.

At this time, the rectifier 91 of the second stabilizer 90 serves to rectify the DC voltage when an overvoltage occurs as the arm short or the resonance overcurrent occurs in the heating unit 80. In addition, the Zener diode ZD2 is connected to the rectifier 91 to limit the input voltage not to be higher than the supply voltage of the comparator 92 to protect the comparator 92. In addition, the comparator 92 compares the overvoltage rectified by the rectifier 91 with a reference voltage to determine whether there is an overvoltage, and when it is determined to be an overvoltage, outputs an arm short generation signal to the photocoupler 93. In addition, the photo coupler 93 is driven when the dark short generation signal is input from the comparator 92, and thus outputs the dark short error signal to the microcomputer 60.

Meanwhile, the power supply unit 100 includes a rectifier (not shown) and a switching mode power supply (SMPS), and receives commercial AC power from an AC power input terminal and converts the AC power to a corresponding DC voltage. ), And the power supply of each block is electrically insulated.

Search box FC: Current Frequency (20Khz ~ 45Khz) AC: Current Consumption tC: system internal temperature UC: voltage level Error display window UL: Low voltage (170V or less) UH: High voltage (above 242V) AH: Overcurrent LS: Insufficient current consumption at 40Khz (at start of oscillation drive); HS: Excessive current consumption SL: 5 consecutive surges for 30 minutes tH: Overheated temperature sensor (60 degrees or higher: system overheated) bo: heatsink overheat tE: Bad temperature sensor

In addition, the display unit 110 serves to display the status and error conditions of the system to the operator under the control of the microcomputer 60 as the status check button 12 is turned on step by step, the display content It is shown in the said [Table 1].

Then, the temperature sensor 120 measures the internal temperature in the device and serves to output the temperature measurement value to the microcomputer 60.

On the other hand, the bimetal 130 serves to detect overheating of the heat sink.

Then, the control method of the electromagnetic induction heating apparatus according to an embodiment of the present invention having the configuration as described above will be described with reference to FIG.

First, when the power source is turned on (ON), the microcomputer 60 determines whether the AC input voltage level is normal (S1).

At this time, when the AC input voltage level is not normal in the first step S1 (NO), the microcomputer 60 sets the current input voltage to "UL (low voltage)" or "UH" through the display unit 110. (High voltage) "and the oscillation output flag is set to" 0 "and returned at the same time (S2). On the other hand, if the AC input voltage level is normal (YES) in the first step (S1), the microcomputer 60 has overheated the internal temperature of the device through the temperature sensor 120 or more than the reference temperature value or the It is determined whether the bimetal 130 is in operation (S3).

At this time, if the internal temperature of the device in the third step (S3) is overheated above the reference temperature value or the bimetal is in operation (YES), the microcomputer 60 through the display unit 110 to the [table] 1] is displayed as "tH" or "bo" and the oscillation output flag is set to "0" and returned at the same time (S4). Here, when the oscillation output flag is set to " 1 ", it indicates a state of " oscillation output ", and " 0 "

If the internal temperature of the device is not overheated above the reference temperature value or the bimetal is not operating (NO) in the third step S3, the microcomputer 60 determines whether the start button 11 is turned on. Determine (S5).

At this time, when the start button 11 is turned on (YES) in the fifth step (S5), the microcomputer 60 checks whether the circuit lock flag is "1" and oscillates if it is "0" (NO). It is checked whether the output flag is "1" (S6). In this case, when the circuit locking flag is set to "1", the "circuit locking" state is shown.

In the sixth step S6, if the oscillation output flag is "0" (NO), the microcomputer 60 checks whether the start oscillation flag is "1", and if it is "0" (YES), the two reference frequencies The oscillator starts oscillating at 45 ms with a delay time DT of OSC1 and OSC2, respectively, and simultaneously operates the fan 83 (S7). Here, when the start oscillation flag is set to "1", it represents a state of "start oscillation completed", and "0" represents a state of "not start oscillation complete".

Thereafter, the microcomputer 60 sets the start oscillation flag to "1" (S8).

At this time, the start oscillation flag is "1" in the seventh step (S7) or after the eighth step (S8), the microcomputer 60 determines whether the current frequency value is equal to 40 Hz, If not equal (NO), the frequency value is decreased by "1" (S9).

Then, the microcomputer 60 determines whether the current frequency is equal to the final target frequency (23kHz), and if it is the same (YES), sets the current consumption value at the present time as the reference current value and sets the oscillation output flag to " While setting to 1 ", the reference frequencies OSC1 and OSC2 are respectively output with a delay time DT and then returned (S10).

On the other hand, if the start button 11 is not turned on in the fifth step S5 (NO), the microcomputer 60 checks whether the oscillation output flag is "1" and if it is "0" (NO). On the other hand, if it is "1" (YES), the oscillation output flag is changed to "0" (S11).

Thereafter, the microcomputer 60 determines whether a predetermined time (about 30 seconds) has elapsed, and if it has passed (YES), stops and returns the fan 83, and if it does not (NO) predetermined Check whether the time has elapsed (S12).

On the other hand, if the oscillation output flag is "1" in the sixth step (S6) (YES), the microcomputer 60 determines whether the current consumption current value is less than the reference consumption current value (S13).

In this case, when the current consumption current value exceeds the reference consumption current value (NO) in the thirteenth step S13, the microcomputer 60 sets two reference frequencies OSC1 and OSC2 to match the reference current value. Output by adjusting (S14).

On the other hand, in the tenth step S10, the current frequency is not equal to the final target frequency 23 kHz (NO), or in the thirteenth step S13, the current consumption current value is equal to or less than the reference consumption current value ( YES), or after the fourteenth step S14, the microcomputer 60 detects an overcurrent from a power input terminal through the first and second stabilizers 50 and 90 or excessively resonates from the heating unit 80. It is determined whether a current is detected (S15).

At this time, if the overcurrent is not detected from the power input terminal in the fifteenth step S15 and the resonance excessive current is not detected from the heating unit 80 (NO), the microcomputer 60 returns while the power input terminal is returned. When the over current is detected from the or the over-resonance current is detected from the heating unit (YES), the oscillation output flag is set to "0" and then the error holding count is increased (S16).

Thereafter, the microcomputer 60 determines whether the error holding has been performed five times or more continuously for 30 minutes, and when the error holding occurs (YES), the display unit 110 displays "SL" and simultaneously displays a circuit. After the locking flag is set to "1", the process proceeds to the twelfth step S12 (S17).

On the other hand, if error holding is not performed five times or more continuously for 30 minutes in the seventeenth step S17 (NO), the microcomputer 60 determines whether or not a predetermined time (about 30 seconds) has elapsed. (YES) The process proceeds to the start button on determination step of the fifth step (S5), and if a predetermined time (about 30 seconds) has not elapsed (NO), the predetermined time elapsed determination operation is performed again (S18).

On the other hand, if the current frequency value is equal to 40 Hz in the ninth step (S9) (YES), the microcomputer 60 determines whether the current load is a proper load (YES) if the appropriate load (YES) The process proceeds to the reduction step of the frequency value "1" in step 9 (S19).

At this time, if the current load is not a proper load (NO) in the nineteenth step (S19), the microcomputer 60 sets the circuit lock flag to "1" and then through the display unit 110 [ "LS (low load)" or "HS (high load)" of Table 1] is displayed (S20).

Thereafter, the microcomputer 60 sets the oscillation output flag to " 0 " and stops and returns the fan 83 (S21).

Although the present invention has been described in more detail with reference to some embodiments, the present invention is not necessarily limited to these embodiments, and various modifications can be made without departing from the spirit of the present invention.

As described above, according to the electromagnetic induction heating apparatus of the present invention, in generating driving pulses for driving a plurality of IGBTs, the plurality of IGBTs are simultaneously turned on by using the same reference frequency having only a constant delay time. There is an excellent effect of reducing the economic loss by eliminating the phenomenon itself.

In addition, according to the present invention, after detecting the working coil short-circuit or the heat sink short-circuit frequently occurring during the operation of the operator, the over-resonance phenomenon of the resonant current, the overcurrent inflow of the power input terminal, and the overheating phenomenon due to the rapid rise in the internal temperature As a countermeasure, a plurality of IGBTs are automatically paused, thereby eliminating breakage of components including expensive IGBTs, thereby enabling system stabilization.

In addition, according to the present invention, by adding a function that accurately informs the operator of the current operating state and error state of the heating device, the operator can quickly grasp the current state and error state of the heating device, thereby making it easy It has the effect of ensuring installation and maintenance work.

Claims (9)

In an electromagnetic induction heating apparatus having a plurality of IGBTs (large capacity TR), A button unit including a start button and a state check button; A rectifier for converting a commercial AC input voltage into a DC high frequency voltage; A current detector for detecting a current consumption of the rectifier; A first stabilizer outputting an error holding signal when an overcurrent is detected from the current sensing unit; When the start button is turned on, the same two reference frequencies OSC1 and OSC2 are output with a delay time DT, respectively. If the current consumption value detected by the current sensing unit is greater than the reference value, the two reference frequencies are corresponding to each other. When the error holding signal or the arm short error signal is input, the reset signal in the low state is output high and the error holding control signal is output. A microcomputer that automatically outputs a reset signal again when a predetermined time elapses and releases the error holding control signal; After receiving two reference frequencies OSC1 and OSC2 having a delay time DT from the micom, respectively, two IGBT oscillation frequencies A and B are generated through a predetermined logic operation, but are high from the micom. An IGBT driving pulse oscillator for stopping the frequency oscillation operation when the reset signal and the error holding control signal are inputted; As the two IGBT oscillation frequencies A and B are received from the IGBT driving pulse oscillator, the two IGBTs are alternately turned on at predetermined intervals t to alternately supply the high frequency voltage to the working coil. A heating unit; A second stabilizer that detects an arm short or excessive resonant current in two IGBTs of the heating unit and outputs an arm short error signal to the microcomputer; A power supply unit supplying power to each block; A display unit configured to display an internal state and an error state of a system to an operator under the control of the microcomputer; And Electromagnetic induction heating apparatus, characterized in that consisting of a bimetal for detecting overheating of the heat sink. The method of claim 1, The device is further provided with a temperature sensor for measuring the internal temperature of the device, The microcomputer outputs a reset signal when the internal temperature of the device measured by the temperature sensor is greater than or equal to a reference temperature value, thereby performing a control operation to stop driving of the IGBT driving pulse oscillator. Electromagnetic Induction Heating Equipment. The method of claim 1, The device is provided between the current sensing unit and the microcomputer, the electromagnetic induction heating device characterized in that it further comprises a buffer for filtering the current consumption value sensed through the current sensing unit to supply to the microcomputer. The method of claim 1, In setting the current consumption reference value, the microcomputer checks the current consumption value when the oscillation of the reference frequencies OSC1 and OSC2 ends after the start button is turned on, and sets the reference value as the reference value. Device. The method of claim 1, The first stabilizer may include a surge voltage detector configured to output a surge voltage when the surge voltage is detected from the current detector; A rectifier for receiving a surge voltage from the surge voltage detector and rectifying the surge voltage to a DC voltage; A zener diode (ZD1) connected to the rectifier to perform voltage stabilization; And And a comparator configured to compare the surge voltage rectified by the rectifier with a reference voltage to determine whether there is an overcurrent, and to output an error holding signal to the microcomputer if it is determined to be an overcurrent. The method of claim 1, After the IGBT driving pulse oscillator receives the first reference frequency OSC1 from the microcomputer, the IGBT driving pulse oscillator passes the first reference frequency OSC1 to the output a as it is, while outputting the first reference frequency to the b output terminal. A first IC calculator for inverting and outputting OSC1); After receiving the second reference frequency OSC2 from the microcomputer, the c output terminal passes the second reference frequency OSC2 as it is, while the d output terminal inverts and outputs the second reference frequency OSC2. A second IC calculator; A transistor (Q1) connected to a reset output terminal of the microcomputer, an emitter terminal to a ground, and a collector terminal to a 5V power input terminal to turn on when a high reset signal is received from the microcomputer; Each input terminal is connected to the a, c output terminals of the first and second IC operation units, the 5V power input terminal, and the collector terminal of the transistor Q1, so that the first and second output terminals are connected to the a and c output terminals of the first and second IC operation units. When the reference frequencies OSC1 and OSC2 are received, NAND calculation is performed and outputted. When the error holding control signal is input from the microcomputer, 5V power is cut off and the operation is stopped when the transistor Q1 is turned on. A first NAND gate; A first input terminal connected to the b and d output terminals of the first and second IC operation units, the 5V power input terminal, and the collector terminal of the transistor Q1, and inverted from the b and d output terminals of the first and second IC operation units; , 2 reference frequencies ( , A second NAND gate outputting a NAND operation when the input signal is received, and the 5V power is cut off when the error holding control signal is input from the microcomputer and the operation is stopped when the transistor Q1 is turned on; A third IC calculator configured to supply a first IGBT oscillation frequency A in which the output frequency of the second NAND gate is inverted to the heating unit; A fourth IC calculator configured to supply a second IGBT oscillation frequency B in which the output frequency of the first NAND gate is inverted to the heating unit; And The input terminal is connected to the reset output terminal of the micom, f input terminal is grounded, g output terminal is connected to the input terminal of the first to fourth IC operation unit, the first to fourth IC operation unit when the reset signal of the microcomputer is low And an or gate which outputs a low signal and drives the low signal, and outputs a low signal to a g output terminal when the reset signal of the microcomputer changes to a high state, thereby stopping all operations of the first to fourth IC operation units. Induction heater. The method of claim 1, The heating unit may include: a first IGBT driver configured to turn on / off the first IGBT according to a first oscillation frequency A output from the IGBT drive pulse oscillator; A second IGBT driver configured to turn on / off the second IGBT according to the second oscillation frequency B output from the IGBT drive pulse oscillator, and alternately turn on / off the first IGBT at a predetermined interval t; ; First and second resonant capacitors Cr1 and Cr2 connected in parallel with the first and second IGBTs with the working coils interposed therebetween; And And a fan installed in the first and second IGBT heat sinks and configured to switch on / off under the control of the microcomputer to cool internal heat. The method of claim 1, The second stabilizer may include: a rectifier rectifying the DC voltage when an overvoltage occurs as the arm short or the resonance overcurrent occurs in the heating unit; A zener diode (ZD2) connected to the rectifier to perform voltage stabilization; A comparator comparing the overvoltage rectified by the rectifier with a reference voltage value to determine whether the overvoltage is detected and outputting an arm short generation signal when it is determined to be overvoltage; And And a photocoupler configured to output an arm short error signal to the microcomputer because the drive is driven when the arm short generation signal is input from the comparator. The method of claim 1, The display unit, as the status check button is turned on step by step "FC: current frequency (20Khz ~ 45Khz)", "AC: current consumption", "tC: system internal temperature", and "UC: voltage" Level "; Error conditions "UL: Low voltage (170V or less)", "UH: High voltage (242V or more)", "AH: Overcurrent", "LS: Low current consumption at 40Khz (starting oscillation drive)", "HS: Excessive current consumption "," SL: 5 consecutive surges for 30 minutes "," bo: Heat sink overheat "," tH: Temperature sensor overheat (60 degrees or more: system internal temperature overheat) ", and" tE: Temperature sensor defective " Electromagnetically induction heating device characterized in that for displaying such a state to the operator.