KR101291864B1 - Dielectric Heating Machine and Using Method By RMS Pulse Control Mechanism - Google Patents

Abstract

The present invention relates to a dielectric heating method and an apparatus using effective pulse control, and in the dielectric heating method, a high voltage pulse is output, and the output control is controlled through a control unit so that a low frequency signal is superimposed on a high frequency fundamental wave component. It outputs through the negative, it is characterized in that the output gain is effectively controlled by adjusting the rate of application of the low frequency superposition component. In the dielectric heating apparatus, a rectifier for converting an input voltage into a direct current, a power factor improving unit for improving the power factor and THD of the power output from the rectifying unit, and receiving a power output from the power factor improving unit for constant voltage and constant current And a control unit for controlling the output unit to output a high frequency pulse through the power supplied through the power conversion unit, and to output the low frequency signal superimposed on the high frequency component output from the output unit.

Description

Dielectric heating method and apparatus using effective pulse control {Dielectric Heating Machine and Using Method By RMS Pulse Control Mechanism}

The present invention relates to a dielectric heating method and apparatus thereof using effective pulse control, and more particularly, to provide a dielectric heating method and a heating device capable of efficiently heating a dielectric, particularly a ferroelectric such as a human body. There is this.

In general, dielectric heating devices are generally applied to materials having non-conductive electrical properties. Heated materials are placed between two electrodes, and high frequency energy is applied to the electrodes to generate heat at a very high rate. to be.

Dielectric heating applies a strong electric field to the dielectric as is already known, induces polarization of molecules, atoms, ions, and electrons constituting the dielectric, and rapidly changes the direction of the electric field. Excitation) is a heating method that occurs due to the dielectric loss of constituent extra-molecular elements of the material by causing the movement of molecules quickly. Therefore, the method proposed to change the degree of polarization motion is composed of a complex control system that changes the level of the output voltage as it is present, and the configuration of the current limiting mechanism on the power rail to be forcibly regulated. It is true that there is room for improvement in the control method because it not only acts as a barrier to current flow, but also has a significant adverse effect on elements and components.

KR 10-0904883 1 is a block diagram of a dielectric heating apparatus according to the prior art. Looking at the configuration, in the frequency stable dielectric heating device, the crystal oscillator 11 for generating an output frequency, the primary frequency divider 12 for dividing the output frequency of the crystal oscillator 11 and the primary frequency divider A phase comparator 13 into which a frequency divided by a period 12 is input, a voltage controlled oscillator 15 to which an output of the phase comparator 13 is input, and an output of the voltage controlled oscillator 15 are input, It is characterized in that it comprises a phase locking loop (10) composed of a secondary divider (14) fed back to the phase comparator (13). As the conventional dielectric heating method, a method of controlling the degree of heating is mainly used by increasing or decreasing the level of the output voltage. If the above prior art degree is applied as it is, it is impossible to control the instantaneous and immediate output voltage considering the complexity of the output circuit for current limitation and the immediate countermeasure against overcurrent overvoltage, considering the high output voltage. The problem of having to go through a sudden voltage rise or fall procedure in order to maintain a proper heating degree is a technical problem that directly affects the stability of the controller. In particular, in the circuit structure in which the boost type switching element for limiting the current is arranged, in the case of controlling the ratio of the current limiting factor, a huge power loss is caused in some cases, and in the worst case, the switching element is destroyed. There are problems that can cause problems and have fatal consequences for the stability and safety of the entire system.

The present invention for solving the above problems is a method of controlling the ratio of the time to output the pulse and the time to stop the output pulse at a certain period to the output control is possible to minimize the power loss, system stability and An object of the present invention is to provide a dielectric heating method capable of ensuring safety.

The present invention for achieving the above object, in the dielectric heating method, outputs a high voltage pulse, the output control is controlled through the control unit so that the low plate signal is superimposed on the high frequency fundamental wave components and output through the output unit, fertilization It is characterized by effectively controlling the output gain by adjusting the rate.

The output unit may include one of a push pull, a flyback, and a bridge topology.

The control unit may control to generate a low frequency superimposed wave simultaneously with the high frequency fundamental wave.

In the dielectric heating apparatus, a rectifier for converting an input voltage into a direct current, a power factor improving unit for improving the power factor and THD of the power output from the rectifying unit, and receiving a power output from the power factor improving unit for constant voltage and constant current And a control unit for controlling the output unit to output a high frequency pulse through the power supplied through the power conversion unit, and to output the high frequency component superimposed on the high frequency component output from the output unit.

The output unit may include one of a push pull, a flyback, and a bridge topology.

The output unit supplies power to the transformer through a switching element and outputs the power, wherein the switching element supplies a frequency to be driven to the transformer through a gate driving driver, and generates a pulse generator and a pulse generator for driving the gate. It characterized in that it comprises a logic circuit for applying a low frequency pulse to the pulse generated by.

In addition, the controller is characterized in that the temperature rise curve data over time is pre-stored in the storage unit when applying a high voltage continuous pulse of any dielectric or the object to be heated.

The controller may be configured to control a low frequency component of several Hz to be output to a fundamental wave output of several KHz or more output to the output unit.

The apparatus may further include a current detector configured to detect a current of power output from the power converter, and an error amplifier configured to compare a relative voltage value of the current detected by the current detector to be input to the controller. When the current output from the reference voltage (Vref) is higher than the reference value is characterized in that for controlling the switching signal of the output unit.

According to the present invention configured and operated as described above, when the fundamental frequency components of the high voltage pulse are continuously output and the low frequency components are superimposed, the high voltage pulses to be output can be effectively controlled for the low frequency components.

In particular, such an effective control method is a comparative method of controlling the degree of heating by converting electrical energy into the form of thermal energy for a dielectric or similar heating sample that is not an electrical or electronic load in which a target sample such as dielectric heating is directly connected to a circuit. For loads with slower response than electro-electrical loads, there is an advantage over conventional control schemes.

1 is a block diagram of a dielectric heating apparatus according to the prior art,
2 is a block diagram showing a logic, electrical connection structure between the entire signal, power and output of the dielectric heating apparatus using the effective pulse according to the present invention,
3 is a block diagram of the overall configuration of a dielectric heating apparatus using an effective pulse according to the present invention;
4 is a diagram illustrating a mixed gate signal of a dielectric heating method using effective pulse control according to the present invention;
5 is a view showing an output waveform of a high voltage pulse for the mixed gate signal according to the present invention;
6 is a view showing the type of temperature rise for a waveform of a high voltage pulse for a mixed gate signal according to the present invention;
FIG. 7 is a diagram illustrating an output waveform of a high voltage pulse with respect to a low frequency superimposed waveform for each aspect ratio output when the system is implemented according to the design method of the present invention. FIG.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the dielectric heating method and apparatus using effective pulse control according to the present invention.

In the dielectric heating method using an effective pulse according to the present invention, in the dielectric heating method, while outputting a high voltage pulse, the output control is controlled through the control unit so that the low frequency signal is superimposed on the high frequency fundamental wave component, and output through the output unit, It is characterized by effectively controlling the output gain by adjusting the rate of application of the low frequency superposition components.

In the dielectric heating apparatus, the dielectric heating apparatus includes a rectifier for converting an input voltage into a direct current, a power factor improving unit for improving the power factor and THD of the power output from the rectifying unit, and a constant voltage supplied with the power output from the power factor improving unit. And a control unit configured to control the constant current to be outputted by outputting a high frequency pulse from the output unit for outputting a high voltage pulse through the power supplied through the power converter, and outputting the high frequency component output from the output unit. It features.

Dielectric heating method and apparatus using the effective pulse control according to the present invention is to superimpose the low frequency to the high frequency fundamental wave and output, and to effectively control the output gain by adjusting the ratio of the low frequency superimposed component as the main technical gist. .

2 is a block diagram showing the overall signal, power and output logic between the dielectric heating device using the effective pulse according to the present invention, the structure showing the electrical connection structure, Figure 3 is a whole of the dielectric heating device using the effective pulse in accordance with the present invention A block diagram of the configuration. As shown, the dielectric heating apparatus according to the present invention includes a rectifier 100, a power factor improving unit 110, a power converter 120, an output unit 130, and a controller 140.

Specifically, the rectifier 100 includes a filter unit (unsigned) for receiving commercial power and converting it into a direct current, a power factor improving unit 110 for improving power factor and THD, and a stable DC power supply to the output unit A power converter 120 for constant current, and an output unit 130 for generating and outputting a high voltage pulse and a control unit 140 for controlling the same.

The rectifier, the power factor improving unit, and the power conversion unit may be configured according to a general design known in the art. Since there are various embodiments in the known technology, the detailed description thereof may be omitted. do.

On the other hand, in the design of the output unit, which is the main configuration of the present invention, the output unit may use a push-pull, flyback, bridge topology, and supplies power to a transformer having a high voltage conversion ratio. A method of supplying power is to use a switching element such as a MosFET, and a gate driving driver 141 matching to the switching element (gate and base required voltage) in order to supply power of a frequency to be driven to a transformer. ). In driving the gate, each pulse generator and control unit connected to a pulse generator for continuously generating a basic drive for generating a pulse and an AND gate, which is a logic circuit for combining the pulse with a control signal of a low frequency component [ 140 (Miccom; MCU)] may be applied or configured to be controlled through one control unit that simultaneously generates and controls all of these fundamental and low frequency overlapping waves.

Here, the control unit should be implanted with the following basic logic structure or software.

1. An algorithm for generating pulses of the frequency fs component having a switching period of the fundamental wave component (an iterative algorithm capable of generating the fundamental switching frequency continuously).

2. It has the data of temperature rise curve data according to time when high voltage continuous pulse is applied to specific dielectric or heating element in advance.

3. It has a condition and hardware interface structure to select the application rate of low frequency components according to the selected heating element.

4. It has data of effective decrease rate of temperature compared with continuous temperature increase due to increase of application rate according to the heating element.

5. Output stop data for target temperature for effective temperature increments.

6. Signal input and pulse generation structure for switching the logic structure related to temperature control among the above logic structure.

7. The error amplifier structure compares the relative voltage value of the current drawn by the current detector and inputs it to the microcomputer. When the signal output from the error amplifier becomes higher than the Vref value, the current is configured to determine the reference value and control the switching signal. .

In addition to the control condition described above, in order to effectively perform specific output control, the following method can be applied and controlled. Among the various methods of controlling the high frequency output, the effective value control method is presented as a method that can easily adjust energy by appropriately adding or subtracting energy to the dielectric acting as a load.The mechanism outputs pulses for a certain time to control the output. It is a kind of Burst type output control that stops output for a certain time. However, a feature different from the conventional method is that it outputs a fundamental frequency output of several hundred KHz or more in the form of a mixture of low frequency components of several Hz, and is not suitable for a system that requires fast response, such as a power delivery system. It is judged to be very suitable for effective control by applying to heating control of relatively insensitive load such as dielectric.

에 저주파

를 간단히 AND 연산을 통하여 혼합하면

의 혼합파형이 생성되며 이 혼합파형을 이용하여 특정한 전력변환 계통을 제어할 때

은

의 변조파의 형태로 출력이 된다.4 is a diagram illustrating a mixed gate signal of a dielectric heating method using effective pulse control according to the present invention, FIG. 5 is a diagram showing an output waveform of a high voltage pulse for a mixed gate signal according to the present invention, and FIG. Figure 7 shows the type of temperature rise for the waveform of the high voltage pulse for the mixed gate signal according to the present invention, FIG. 7 shows the output waveform of the high voltage pulse for the low frequency superimposed waveform for each ratio output when the system is implemented according to the design method of the present invention. The figure shown. Relatively high fundamental switching frequency as shown

Low frequency to

Is simply a simple AND operation

Mixed waveforms are generated, and the mixed waveforms are used to control a specific power conversion system.

silver

The output is in the form of a modulated wave.

의 실효값을

,

의 주기를

, On Time을

, Off Time을

하면, 아래와 [수학식 1]과 같은 식으로 정리할 수 있다.
At this time, fundamental wave pulse

The effective value of

,

Cycle of

On Time

, Off Time

Then, it can be summarized as shown in [Equation 1].

In addition, the characteristics of temperature control for the control are increased when the output is applied as shown in FIG. 6 and decreases at the moment when the output is stopped. The degree of warming can be properly controlled by increasing and decreasing the turn-on ratio of the low frequency components.

The present invention configured as described above is a method of controlling the ratio of output time and stop time of outputting pulses at regular intervals to output power, minimizing power loss, and ensuring stability and safety of the system. There are advantages to it. While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. On the contrary, those skilled in the art will appreciate that many modifications and variations of the present invention are possible without departing from the spirit and scope of the appended claims. And all such modifications and changes as fall within the scope of the present invention are therefore to be regarded as being within the scope of the present invention.

100: rectification part
110: power factor improvement unit
120: power conversion unit
121: current detector
122: error amplifier
130:
140:
141: drive drive
150:
160: input / output unit

Claims (9)

In a dielectric heating method for heating a dielectric by applying a high voltage pulse to the electrodes across the dielectric to be heated by using a dielectric heating apparatus including a rectifying unit, a power factor improving unit, a power conversion unit, an output unit, and a control unit,
The output unit outputs a high voltage pulse, and outputs a high voltage pulse by controlling the output unit by the control unit so that a low frequency signal is superimposed on a high frequency fundamental wave component of the high voltage pulse, and controlling the output unit by the control unit for a predetermined time. The output gain is controlled by adjusting the rate of application of low frequency superposition components by outputting pulse and stopping output for a certain time.
The current of the power output from the power conversion unit is detected by the current detector, the relative voltage value of the current detected by the current detector is compared to the error amplifier and input to the controller, the error amplifier by the controller And controlling the switching signal of the output unit by determining a reference value when the current output from the reference voltage is higher than the reference voltage Vref. The image processing apparatus according to claim 1,
Dielectric heating method consisting of any one of push-pull, flyback, bridge topology. The apparatus of claim 1,
Dielectric heating method for controlling the high frequency fundamental wave to generate the low frequency superimposed wave at the same time. In a dielectric heating device,
A rectifier for converting an input voltage into a direct current;
A power factor improving unit for improving power factor and THD of power output from the rectifier;
A power converter configured to receive the power output from the power factor improving unit and convert the power into a constant voltage and a constant current;
An output unit for outputting a high voltage pulse through power supplied through the power converter; And
And a controller configured to superimpose and output a low frequency signal on a high frequency component of a high voltage pulse output from the output unit.
And a current detector for detecting a current of the power output from the power converter, and comparing the relative voltage value of the current detected by the current detector to an input to the controller. And a reference value when the current output from the error amplifier is higher than the reference voltage Vref to control the switching signal of the output unit. The method of claim 4, wherein the output unit,
Dielectric heating device consisting of any one of push-pull, flyback and bridge topologies. The method of claim 4, wherein the output unit,
Powers the transformer through a switching element to output a high voltage pulse,
The switching device supplies a frequency to the transformer to drive through a gate drive driver,
And a logic circuit for applying a low frequency pulse to the pulse generated by the pulse generator. The method of claim 4, wherein the control unit,
A dielectric heating apparatus having a storage unit in which a temperature rising curve data is stored with time when a high voltage continuous pulse is applied to an arbitrary dielectric material or a heated object. The method of claim 4, wherein the control unit,
Dielectric heating device for controlling the output unit to be output by mixing a low-frequency component of several Hz to the fundamental wave of several hundred KHz or more output from the output unit.
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