KR0179537B1 - Resonance type induction heating cooker - Google Patents

Abstract

The present invention is an electromagnetic induction heating cooker, which is intended to heat a plurality of heating plates using a single inverter, it is possible to heat each of the plurality of heating plates through time division control, to prevent problems caused by interference sound, soft The present invention relates to a resonant electromagnetic induction heating cooking device for multi-output control to reduce switching losses using a switching method.

In the case of the conventional frequency control, interference sounds are generated by the difference in operating frequency between adjacent working coils, so that accurate output control of the working coils is not performed, and from the rectifying means and the rectifying means of the input stage as much as each configured inverter. Since the L and C filters must be configured to smooth and filter the voltages of the L and C filters, the entire circuit becomes complicated, and there is a problem in that the economy of the device configuration is lacking.

The present invention proposes a resonant type electromagnetic induction heating cooker to solve the above problems generated in the electromagnetic induction heating cooking device for multi-output control, by means of a single inverter circuit with a power applied from a common rectifying means. It is possible to heat a plurality of heating plates through time division control, thereby minimizing circuit components and preventing interference noise generated during multi-output control, so that the output power of the working coil can be appropriately controlled and economical multi-output control can be achieved. It is to provide an electromagnetic induction heating cooking device, and to minimize the loss of the switching element by using a soft switching method, it is possible to minimize the loss of the switching element.

Description

Resonant Electromagnetic Induction Heating Cooker for Multiple Force Control

1 is a circuit diagram showing the configuration of a conventional general electromagnetic induction heating cooking apparatus.

Figure 2 is a circuit diagram showing the configuration of the resonant type electromagnetic induction heating cooking apparatus for multi-output control of the present invention.

3 is a view showing each sub-waveform when the working coil (L12) in the resonant electromagnetic induction heating cooking apparatus for multi-output control of the present invention,

(a)-(c) is an on / off switching waveform diagram of a switching element.

(d) is a waveform diagram of the current change of the working coil operated by the switching waveforms of FIGS.

(e) is voltage waveform diagram of resonant capacitor.

(f) to (h) are voltage waveform diagrams of the respective switching elements.

4 is a view showing each sub-waveform when the working coil (L12) in the resonant electromagnetic induction heating cooking apparatus for multi-output control of the present invention,

(a)-(c) is an on / off switching waveform diagram of a switching element.

(d) is a waveform diagram of the current change of the working coil operated by the switching waveforms of FIGS.

(e) is a voltage waveform diagram of a resonant capacitor.

Figure 5 is a circuit diagram showing the configuration of another embodiment of the resonant electromagnetic induction heating cooking apparatus for multi-output control of the present invention.

* Explanation of symbols for main parts of the drawings

11 power supply 12 rectifier

13: Inverter

The present invention is an electromagnetic induction heating cooker, each inverter module (Inverter Module) is connected in parallel to configure the inverter circuit and configured, the inverter circuit, so that each of the plurality of heating plates through the time-division control of each inverter module The present invention relates to a resonant electromagnetic induction heating cooking device for multi-output control to prevent problems caused by interference noises and to reduce switching losses using a soft switching method.

In the conventional electromagnetic induction heating cooking apparatus for multi-output control, in order to heat several working coils, a plurality of inverter circuits are configured in parallel to one input power source, and the configuration and operation thereof will be described with reference to FIG. Is as follows.

As shown in FIG. 1, the conventional electromagnetic induction heating cooking configuration includes a power supply unit 1 for supplying power to each circuit unit, and a rectifying unit rectifying power input through the power supply unit 1. (2), the circuit including the choke coil (L1) and condenser (C1) for smoothing the rectified power, and the components of the inverter (3) for heating and heating the heating plate by receiving the smoothed power input is configured as described above Characterized in that a plurality (n) is connected to the power supply unit 1, the inverter 3 is a transistor that is switched to receive the switching power supplied from the configured Switched Mode Power Supply (SMPS) unit as a base A working coil for heating the heating plate by resonating with the diodes D1 and D2 and the resonant capacitor C2, which are arranged in anti-parallel to each of the transistors Q1 and Q2 for the protection of the Q1 and Q2 and the transistors Q1 and Q2. Sphere, including components of (Lr1) It is made.

In the electromagnetic induction heating cooking device having such a configuration is to rectify one input power to heat the heating plate through the inverter circuit is configured,

In order to heat several working coils Lr1, Lr2 ..... Lrn, the inverters 3,3-1,3-2, ..... 3-n are configured in parallel as above. Is made possible.

Then, in the conventional electromagnetic induction heating cooking apparatus to heat a plurality of heating plates as described above, looking at the heating operation process of the working coil as follows.

The power supplied from the power supply unit 1 is rectified to DC power through the rectifying unit 2, the power rectified in the rectifying unit 2 is smoothed while passing through the choke coil (L1) and condenser (C1) (3) is applied.

Inverter 3 receives the same power as above and heats working coil Lr1 by switching transistors Q1 and Q2, thereby heating the cooking object of the heating plate, and transistors Q1 and Q2 are SMPS. Switching is performed by receiving a separate switching voltage from a part (not shown in the drawing).

Looking at the heating operation of the working coil Lr1 by the switching operation of the transistors Q1 and Q2, first, the SMPS unit applies an initial switching voltage to the base of the transistor Q2.

The transistor Q2 is switched on by a switching voltage applied to the base, and since the transistor Q2 is switched on, the power applied through the rectifying unit 2 is in a state in which the transistor Q1 is turned off. A loop is formed as the transistor Q2 through the coil Lr1, and the working coil Lr1 resonates by the loop formed as described above.

At this time, when the SMPS unit applies a switching voltage to the base of the transistor Q1 to turn on the transistor Q1 and turns off the transistor Q2, the transistor Q1 is switched on while being accumulated in the working coil Lr1. A loop is formed through the transistor Q1 in the reverse direction by the current, so that a current flows in the working coil Lr1.

The switching is repeated to heat the working coil Lr1, and to control the current flowing in the working coil Lr1 according to the on-switching time of the transistors Q1 and Q2, that is, the duty ratio. do.

The inverters 3, 3-1, ..., 3-n configured to heat the heating plate by performing the above process, and the output power control of each of the duty through the frequency control as mentioned above This is achieved by changing the ratio.

In this case, interference sound is generated by the difference of operating frequency between adjacent working coils, so that accurate output control of the working coils is not performed. Since the L and C filters to be smoothed and filtered must be configured, the entire circuit becomes complicated, and there is a problem in that the economy of the device configuration is lacking.

The present invention proposes a resonant electromagnetic induction heating cooker in order to solve the above problems generated in the electromagnetic induction heating cooking apparatus for multi-output control, receiving two heating plates by receiving power applied from a common rectifying means. Minimizes the circuit components by constructing a module including internal components that enable heating, and by heating a plurality of heating plates through time division control by a single inverter circuit composed of a parallel connection configuration of the configured modules. In order to prevent interference noise generated during multi-output control, it is possible to provide appropriate output control of the working coil, and to provide an electromagnetic induction heating cooking device for multi-output control with improved economic efficiency.

In addition, by minimizing the switching loss by using a soft switching method, it is possible to minimize the loss of the switching device.

The resonant electromagnetic induction heating cooking device for the multi-output control of the present invention comprises a power supply means, a rectifier of the supplied power, and a plurality of inverters that receive each of the switching operations by receiving the rectified power from the rectifying means. As a circuit,

Figure 2 is a view showing a preferred embodiment of the configuration, with reference to Figure 2 looks at the configuration of the resonance type electromagnetic induction heating cooking apparatus for multi-output control of the present invention.

Rectifier 12 for rectifying the power supply unit 11 and the input power, choke coil L11 and condenser C11 for smoothing and filtering the rectified power, and the smoothed power source to a separate switching power source. A transistor Q11 switched and outputted, a protection diode D11 anti-parallel connected to the transistor Q11, and an inverter unit 13 for receiving and switching a separately input switching power source to heat the heating plate. And an auxiliary resonant capacitor C12 of the inverter unit 13 and a protection diode D12 that is anti-parallel to the auxiliary resonant capacitor C12.

The inverter unit 13 receives a separate switching power source and switches on / off switching transistors Q12 and Q13 for heating control operation of the working coils L12 and L13, and anti-parallel connection to the transistors Q12 and Q13. The protective diodes D13 and D14, the condenser C13 to resonate with the working coils L12 and L13, and the condenser C13 to heat the heating plate by switching control of the transistors Q11 and Q12. It is characterized by consisting of the working coils L12 and L13 and the diode D15 connected in parallel with the capacitor C13.

The resonance type electromagnetic induction heating cooking device for multi-output control of the present invention having the above configuration is an inverter circuit including only one module unit, that is, one inverter unit, and an embodiment for heating two heating plates. Referring to the operation of the present invention with reference to the following.

FIG. 3 is a view illustrating heating of the working coil L12, for example, waveforms of respective parts. Referring to FIG. 3, first, as in FIG. 3A, transistors Q11 and Q12 are turned on at t0. Then, the current is linearly increased in the working coil L12 through the transistors Q11 and Q12 by the input DC power supply as shown in (d) of FIG.

After that, when the transistor Q11 is turned off by a certain set value, the auxiliary resonance condenser C12 and the working coil L12 resonate for a very short time due to the current accumulated in the working coil L12.

When the resonance proceeds as described above and the voltage of the auxiliary resonance capacitor C12 drops to zero, the current of the working coil L12 is the transistor Q12. Working coil (L12) Freewheeling of the diode D12 is performed.

At this time, when the transistor Q12 is turned off at t3 and the transistor Q13 is turned on, the working coil L12 and the capacitor C13 resonate.

Thereafter, when the working coil L12 resonates with the condenser C13 and the voltage of the condenser C13 rises and becomes zero again as shown in (e) of FIG. 3, the current of the working coil L12 at t5. Working coil (L12) Diode (D15) The circuit is cycled through the transistor Q13.

When the current is circulated in the above path, when the transistor Q13 is turned off at t6, the auxiliary resonance capacitor C12 and the working coil L12 are very short due to the accumulated current of the working coil L12. The resonance is performed for a time, and by this resonance, the capacitor C12 is charged to be equal to the input voltage.

Since the residual current of the working coil L12 flows to the input side through the antiparallel diode D11 connected to the transistor Q11, the current of the working coil L12 decreases linearly as shown in (d). Done.

At this time, since the voltages of the transistors Q11 and Q12 are zero, the transistors Q11 and Q12 are turned on again at the zero voltage condition at t7.

As described above, when the transistor Q11 is switched on again, as in (d), when the current of the working coil L12 drops to zero, one cycle 1T ends.

If the above operation is repeated, the appropriate power is to be delivered to the working coil (L12).

In the above description, an operation process for one working coil L12 is described. Another working coil L13 also executes an operation by the above application process, and a second operation process for the working coil L13 is performed. A brief description with reference to FIG. 4 is as follows.

As in the working coil L12, as in (a) of FIG. 4, when the transistors Q11 and Q13 are turned on at t0, a loop is formed by the transistors Q11 and Q13 by the input DC power supply. In (L13), the current increases linearly as shown in (d) of FIG.

After that, when the transistor Q11 is turned off by a predetermined value, the auxiliary resonance capacitor C12 and the working coil L13 resonate for a very short time due to the current accumulated in the working coil L13.

When the resonance proceeds as described above and the voltage of the auxiliary resonance capacitor C12 drops to zero, the current of the working coil L13 is the working coil L13. Transistor (Q13) The path of the diode D12 is circulated.

At this time, when the transistor Q13 is turned off at t3 and the transistor Q12 is turned on, the working coil L13 and the capacitor C13 resonate.

Thereafter, the resonance of the working coil L13 and the condenser C13 proceeds, and as shown in FIG. Walking coil (L13) Transistor (Q12) The path of the diode D15 is circulated.

When the current is circulated in the above path, when the transistor Q12 is turned off at t6, the auxiliary resonance capacitor C12 and the working coil L13 are very short due to the accumulated current of the working coil L13. The resonance is performed for a time, and by this resonance, the capacitor C12 is charged to be equal to the input voltage.

Since the residual current of the working coil L13 flows to the input side through the antiparallel diode D11 connected to the transistor Q11, the current of the working coil L13 decreases linearly as shown in (d). Done.

At this time, since the voltages of the transistors Q11 and Q13 are zero, the transistors Q11 and Q13 are turned on again at the zero voltage condition at t7.

As described above, when the transistor Q11 is switched on again, as shown in (d), when the current of the working coil L13 drops to zero, one cycle 1T ends.

If the above operation is repeated, the appropriate power is to be delivered to the working coil (L13).

As described above, since one inverter circuit is capable of heating two working coils and uses time-division control to control the operation switching time of each other, there is no problem of generating an interference sound between working coils, and a soft switching method. Since it is controlled by using, the loss is small as in FIG.

FIG. 5 is a circuit diagram showing a configuration of a resonant electromagnetic induction heating apparatus capable of heating four heating plates. In the case of such a resonant electromagnetic induction heating apparatus, the configuration of the inverter unit 13 is arranged in parallel. In a further configuration, the four working coils L12, L13, L14, and L15 can be operated through time division control, respectively, and the operation progress is performed in the same manner as the apparatus for heating the two heating plates.

As described above, it is possible to heat a plurality of heating plates while using a small number of switching elements, and to execute the output control of the working coil through time division control, thereby preventing the occurrence of interference sound and providing a soft switching method. By minimizing the switching loss by using, not only has the characteristics of low noise, but also has the effect of improving the size and economics of the inverter.

In addition, since the heating plate is gradually increasing in the case of the electromagnetic induction heating cooker generally used at home, by applying the present invention thereof, it becomes possible to design a device that meets the needs of the user.

Claims (4)

The power supply unit 11, the rectifier 12 for rectifying the input power, the choke coil (L11) and condenser (C11) to perform the smoothing and filtering of the rectified power, and the smoothed power separate switching power supply Is connected to the transistor Q11 that is switched and outputted by the output signal, the protection diode D11 that is connected in anti-parallel to the transistor Q11, and the inverter unit 13 that receives and switches the switching power input separately to heat the heating plate. And the components of the auxiliary resonant capacitor C12 of the inverter unit 13 and the protection diode D12 that is anti-parallel to the auxiliary resonant capacitor C12. Resonant type electromagnetic induction heating cooking device for. The transistor unit (13) of claim 1, wherein the inverter unit (13) receives a separate switching power source and switches the on / off switch to operate the heating coil (L12. L13) for heat control operation. Resonant with the capacitor C13 by switching control of the protective diodes D13 and D14 connected in anti-parallel to the Q13) and the capacitors C13 and transistors Q11 and Q12 that are resonated with the working coils L12 and L13. And a working coil (L12, L13) for heating the heating plate, and a diode (D5) connected in parallel with the condenser (C3). The resonant type according to claim 1, wherein the inverter unit (13) is connected to a plurality (n) in parallel to heat a plurality of heating plates (n × 2). Electromagnetic Induction Heating Cooker The resonant type electromagnetic induction heating cooking device according to claim 1 or 2, wherein the output control of the inverter unit (13) is performed through time division control.