TWI584694B - Control systems and induction cookers to induction cookers - Google Patents

Control systems and induction cookers to induction cookers Download PDF

Info

Publication number
TWI584694B
TWI584694B TW105107101A TW105107101A TWI584694B TW I584694 B TWI584694 B TW I584694B TW 105107101 A TW105107101 A TW 105107101A TW 105107101 A TW105107101 A TW 105107101A TW I584694 B TWI584694 B TW I584694B
Authority
TW
Taiwan
Prior art keywords
voltage
sampling
switching device
signal
input
Prior art date
Application number
TW105107101A
Other languages
Chinese (zh)
Other versions
TW201725934A (en
Inventor
Qian Fang
Hua-Wei Lu
ting-zhi Yuan
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed filed Critical
Application granted granted Critical
Publication of TWI584694B publication Critical patent/TWI584694B/en
Publication of TW201725934A publication Critical patent/TW201725934A/en

Links

Classifications

    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B6/00—Heating by electric, magnetic or electromagnetic fields
    • H05B6/02—Induction heating
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B6/00—Heating by electric, magnetic or electromagnetic fields
    • H05B6/02—Induction heating
    • H05B6/06—Control, e.g. of temperature, of power

Landscapes

  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Induction Heating Cooking Devices (AREA)
  • Ac-Ac Conversion (AREA)
  • Electronic Switches (AREA)

Description

用於電磁爐的控制系統和電磁爐 Control system and induction cooker for induction cooker

本發明涉及電路領域，更具體地涉及一種用於電磁爐的類比控制系統和電磁爐。 The present invention relates to the field of circuits, and more particularly to an analog control system and an induction cooker for an induction cooker.

電磁爐又名電磁灶，是現代廚房革命的產物，它無需明火或傳導式加熱即讓熱直接在鍋底產生，因此熱效率得到了極大地提高。電磁爐主要包括以下兩個部分：用於產生高頻交變磁場的電子線路系統；以及用於固定電子線路系統並承載鍋具的結構性外殼。 The induction cooker, also known as the induction cooker, is the product of the modern kitchen revolution. It does not require open flame or conductive heating to allow heat to be generated directly at the bottom of the pot, so the thermal efficiency is greatly improved. The induction cooker mainly comprises the following two parts: an electronic circuit system for generating a high-frequency alternating magnetic field; and a structural outer casing for fixing the electronic circuit system and carrying the cookware.

第1圖是示出電磁爐的工作原理的示意圖。如第1圖所示，電磁爐是採用磁場感應渦流原理，利用高頻電流通過環形線圈產生的無數封閉磁場使鍋體本身自行快速發熱來實現對鍋內食物的加熱的。具體地，當環形線圈中通過高頻電流時，環形線圈周圍產生高頻交變磁場；當高頻交變磁場的磁力線通過導磁材料的底部(例如，鐵質鍋的鍋底)時，鍋底在高頻交變磁場的作用下會產生無數小渦流，使得鍋底迅速釋放出大量熱量從而達到加熱鍋內食物的目的。 Fig. 1 is a schematic view showing the operation principle of the induction cooker. As shown in Fig. 1, the induction cooker adopts the principle of magnetic field induced eddy current, and uses the infinite closed magnetic field generated by the high-frequency current through the toroidal coil to make the body itself heat rapidly to achieve heating of the food in the pot. Specifically, when a high-frequency current is passed through the toroidal coil, a high-frequency alternating magnetic field is generated around the toroidal coil; when the magnetic field line of the high-frequency alternating magnetic field passes through the bottom of the magnetically permeable material (for example, the bottom of the pot of the iron pot), the bottom of the pot is Under the action of the high-frequency alternating magnetic field, numerous small eddy currents are generated, so that the bottom of the pot quickly releases a large amount of heat to achieve the purpose of heating the food in the pot.

第2圖是示出電磁爐中用於產生高頻交變磁場的電子線路系統的示意圖。如第2圖所示，電子線路系統200包括整流橋202、LC濾波器204、電磁線圈(即，上面提到的環形線圈)206、諧振電容208、以及開關器件210(例如，絕緣閘雙極型電晶體(Insulated Gate Bipolar Transistor,IGBT))。其中，整流橋202和LC濾波器204對交流輸入電壓VAC進行全波整流和LC濾波，以形成整流後的輸入電壓Vin；開關器件210不斷地接通和斷開，其中當開關器件210接通時整流後的輸入電壓Vin被施加在電磁線圈206兩端，流過電磁線圈206的正向電流增加，當開關 器件210斷開時電磁線圈206與諧振電容208形成高頻諧振，電磁線圈206上的電壓反向，流經電磁線圈206的電流減小；流過電磁線圈206的變化電流形成高頻交變磁場，高頻交變磁場產生的交變磁力線穿過鍋底，使得鍋底發熱。 Fig. 2 is a schematic view showing an electronic circuit system for generating a high-frequency alternating magnetic field in an induction cooker. As shown in FIG. 2, the electronic circuit system 200 includes a rectifier bridge 202, an LC filter 204, an electromagnetic coil (ie, the above-mentioned toroidal coil) 206, a resonant capacitor 208, and a switching device 210 (eg, an insulated gate bipolar). Insulated Gate Bipolar Transistor (IGBT)). The rectifier bridge 202 and the LC filter 204 perform full-wave rectification and LC filtering on the AC input voltage V AC to form a rectified input voltage V in ; the switching device 210 is continuously turned on and off, wherein the switching device 210 The rectified input voltage V in is applied to both ends of the electromagnetic coil 206 when turned on, and the forward current flowing through the electromagnetic coil 206 is increased. When the switching device 210 is turned off, the electromagnetic coil 206 and the resonant capacitor 208 form a high frequency resonance, and the electromagnetic The voltage on the coil 206 is reversed, and the current flowing through the electromagnetic coil 206 is reduced; the varying current flowing through the electromagnetic coil 206 forms a high-frequency alternating magnetic field, and the alternating magnetic field lines generated by the high-frequency alternating magnetic field pass through the bottom of the pot, so that the bottom of the pot is heated. .

目前，電磁爐大都採用第2圖所示的電子線路系統，並利用以微控制器單元(Microcontroller Unit,MCU)為核心的數位控制電路來實現對第2圖所示的電子線路系統的功率調節和保護。眾所周知，輸入功率是輸入電壓與輸入電流的乘積。第2圖所示的電子線路系統200的交流輸入電壓(即，VAC)是電網電壓，基本固定，所以只要控制輸入到電子線路系統200的平均電流就可以控制電子線路系統200的輸入功率。輸入到電子線路系統200的電流是從電網端流入的電流，當開關器件210接通時有電流流入電子線路系統200，當開關器件210斷開時無電流流入電子線路系統200。所以，只要控制開關器件210的接通和斷開就可以控制輸入到電子線路系統200的電流，從而控制其輸入功率。 At present, most of the induction cookers use the electronic circuit system shown in Fig. 2, and use the digital control circuit with the microcontroller unit (MCU) as the core to realize the power adjustment of the electronic circuit system shown in Fig. 2. protection. As is known, the input power is the product of the input voltage and the input current. The AC input voltage (i.e., V AC ) of the electronic circuit system 200 shown in FIG. 2 is the grid voltage and is substantially fixed, so that the input power of the electronic circuit system 200 can be controlled as long as the average current input to the electronic circuit system 200 is controlled. The current input to the electronic circuit system 200 is the current flowing from the grid terminal. When the switching device 210 is turned on, current flows into the electronic circuit system 200, and when the switching device 210 is turned off, no current flows into the electronic circuit system 200. Therefore, the current input to the electronic circuit system 200 can be controlled as long as the switching device 210 is turned on and off, thereby controlling its input power.

在以全數位方式對第2圖所示的電子線路系統進行功率調節和保護時，通過對交流輸入電壓和流過開關器件210的平均電流進行取樣來對交流輸入電壓和流過開關器件210的平均電流進行類比/數位(Analog-to-digital,A/D)轉換，從而形成數位電壓信號和數位電流信號，MCU通過將數位電壓信號與數位電流信號相乘進行功率計算並將計算結果與設定功率相比較來調節開關器件210的接通時間(Ton)。因為數位控制運算需要時間，所以對於瞬間電流與瞬間電壓的控制往往滯後。 When the power adjustment and protection of the electronic circuit system shown in FIG. 2 is performed in a full digital manner, the AC input voltage and the current flowing through the switching device 210 are sampled by sampling the AC input voltage and the average current flowing through the switching device 210. The average current is analog-to-digital (A/D) converted to form a digital voltage signal and a digital current signal. The MCU multiplies the digital voltage signal by the digital current signal to calculate the power and set the calculation result and setting. The power is compared to adjust the on time (Ton) of the switching device 210. Since the digital control operation takes time, the control of the instantaneous current and the instantaneous voltage often lags behind.

本發明提供了一種用於電磁爐的控制系統和電磁爐。 The present invention provides a control system and an induction cooker for an induction cooker.

根據本發明實施例的用於電磁爐的控制系統，其中電磁爐包括開關器件和電磁線圈，開關器件通過不斷地接通與斷開來使電磁線圈產生高頻交變磁場，該控制系統包括：開關控制元件，被配置為對電磁爐的輸入取樣電壓與閾值電壓進行比較，並根據輸入取樣電壓與閾值電壓 之間的比較結果來控制開關器件的接通與斷開，其中，輸入取樣電壓是通過對電磁爐的交流輸入電壓進行整流分壓後取樣生成的。 A control system for an induction cooker according to an embodiment of the present invention, wherein the induction cooker includes a switching device and an electromagnetic coil, and the switching device generates a high-frequency alternating magnetic field by continuously turning on and off, the control system comprising: switch control The component is configured to compare an input sampling voltage of the induction cooker with a threshold voltage, and according to the input sampling voltage and the threshold voltage The result of the comparison is to control the on and off of the switching device, wherein the input sampling voltage is generated by rectifying and dividing the AC input voltage of the induction cooker.

根據本發明實施例的電磁爐，包括：開關器件；電磁線圈；以及以上所述的控制系統。 An induction cooker according to an embodiment of the present invention includes: a switching device; an electromagnetic coil; and the control system described above.

200‧‧‧電子線路系統 200‧‧‧Electronic circuit system

202‧‧‧整流橋 202‧‧‧Rectifier Bridge

204‧‧‧LC濾波器 204‧‧‧LC filter

206‧‧‧電磁線圈 206‧‧‧Electromagnetic coil

208‧‧‧諧振電容 208‧‧‧Resonant capacitor

210‧‧‧開關器件 210‧‧‧Switching device

VAC‧‧‧交流輸入電壓 V AC ‧‧‧AC input voltage

Vin‧‧‧輸入電壓 V in ‧‧‧ input voltage

MCU‧‧‧微控制器單元 MCU‧‧‧Microcontroller Unit

A/D‧‧‧類比/數位 A/D‧‧‧ analog/digital

Ton‧‧‧接通時間 Ton‧‧‧Connected time

Toff‧‧‧斷開時間 Toff‧‧‧ disconnection time

400‧‧‧控制系統 400‧‧‧Control system

Vth‧‧‧閾值電壓 Vth‧‧‧ threshold voltage

Vcs‧‧‧電流取樣電壓 Vcs‧‧‧ current sampling voltage

Vref‧‧‧參考電壓 Vref‧‧‧reference voltage

comp‧‧‧功率表徵信號 Comp‧‧‧Power characterization signal

ramp‧‧‧速率表徵信號 Ramp‧‧‧ rate characterization signal

VIGBT‧‧‧變化斜率的電壓 V IGBT ‧‧‧Variable slope voltage

Vac_in‧‧‧輸入取樣電壓 Vac_in‧‧‧ input sampling voltage

Vth_H、Vth_L‧‧‧雷擊保護閾值 Vth_H, Vth_L‧‧‧ lightning strike protection threshold

C1、C2‧‧‧電容 C1, C2‧‧‧ capacitor

S1、S2、S3‧‧‧信號開關 S1, S2, S3‧‧‧ signal switch

Comp 1、Comp 2、Comp 3‧‧‧比較器 Comp 1, Comp 2, Comp 3‧‧‧ Comparator

從下面結合附圖對本發明的具體實施方式的描述中可以更好地理解本發明，其中：第1圖是示出電磁爐的工作原理的示意圖；第2圖是示出電磁爐中用於產生高頻交變磁場的電子線路系統的示意圖；第3圖示出了第2圖所示的開關器件210的驅動信號、發生雷擊時整流後的輸入電壓Vin、以及發生雷擊時開關器件210上的電壓和電流的波形圖；第4圖是示出根據本發明實施例的電磁爐的電子線路系統的電路圖；第5a圖是示出第4圖中所示的生成第一控制信號的電路部分的另一實施例的電路圖；第5b圖示出了開關器件210的驅動信號、用於控制第5a圖中的開關S1的接通與斷開的S1信號、輸入取樣電壓Vac_in、雷擊保護閾值Vth_H和Vth_L的波形圖；第6a圖是示出第4圖中所示的生成第一控制信號的電路部分的又一實施例的電路圖；第6b圖示出了開關器件210的驅動電壓、S2信號、S3信號的波形圖。 The invention can be better understood from the following description of the embodiments of the invention, in which: FIG. 1 is a schematic diagram showing the operation of the induction cooker, and FIG. 2 is a diagram showing the high frequency used in the induction cooker A schematic diagram of an electronic circuit system of an alternating magnetic field; FIG. 3 shows a driving signal of the switching device 210 shown in FIG. 2, an input voltage Vin that is rectified when a lightning strike occurs, and a voltage and voltage on the switching device 210 when a lightning strike occurs. Waveform diagram of current; FIG. 4 is a circuit diagram showing an electronic circuit system of an induction cooker according to an embodiment of the present invention; FIG. 5a is another embodiment showing a circuit portion for generating a first control signal shown in FIG. The circuit diagram of the example; FIG. 5b shows the driving signal of the switching device 210, the S1 signal for controlling the turning on and off of the switch S1 in FIG. 5a, the input sampling voltage Vac_in, the lightning strike protection thresholds Vth_H and Vth_L Figure 6a is a circuit diagram showing still another embodiment of the circuit portion for generating the first control signal shown in Figure 4; Figure 6b shows the driving voltage, S2 signal, and S3 signal of the switching device 210. FIG waveform.

下面將詳細描述本發明的各個方面的特徵和示例性實施例。在下面的詳細描述中，提出了許多具體細節，以便提供對本發明的全面理解。但是，對於本領域技術人員來說很明顯的是，本發明可以在 不需要這些具體細節中的一些細節的情況下實施。下面對實施例的描述僅僅是為了通過示出本發明的示例來提供對本發明的更好的理解。本發明決不限於下面所提出的任何具體配置和演算法，而是在不脫離本發明的精神的前提下覆蓋了元素、部件和演算法的任何修改、替換和改進。在附圖和下面的描述中，沒有示出公知的結構和技術，以便避免對本發明造成不必要的模糊。 Features and exemplary embodiments of various aspects of the invention are described in detail below. In the following detailed description, numerous specific details are set forth However, it will be apparent to those skilled in the art that the present invention can be Implementation is not required without some of these specific details. The following description of the embodiments is merely provided to provide a better understanding of the invention. The present invention is in no way limited to any specific configurations and algorithms presented below, but without departing from the spirit and scope of the invention. In the drawings and the following description, well-known structures and techniques are not shown in order to avoid unnecessary obscuring the invention.

第3圖示出了第2圖所示的開關器件210的驅動信號、發生雷擊時整流後的輸入電壓Vin、以及發生雷擊時開關器件210上的電壓和電流的波形圖。如第3圖所示，在電磁爐處於工作狀態時發生雷擊的情況下，整流後的輸入電壓Vin衝高，使得加在電磁線圈206兩端的電壓升高，電磁線圈206產生的電感電流的斜率增大；然而，由於數位控制運算的滯後，開關器件210的接通時間Ton不會有任何變化；因為電磁線圈206產生的電感電流的斜率增大，所以在開關器件210的接通時間Ton結束時，流過開關器件210的峰值電流Ipk會比上一週期大很多； 根據，開關器件210上的電壓VIGBT將會增大；如果開關器件210上的電壓VIGBT超過其耐壓，開關器件210將會炸毀。即使MCU通過外加輸入電壓偵測電路感測到整流後的輸入電壓Vin衝高，但MCU經過運算，最快保護開關器件210的運算時間是1.3us，使開關器件210斷開已經是1.3us後的事情了，所以利用MCU來對開關器件210進行過流保護是一個瓶頸。 Fig. 3 is a view showing a driving signal of the switching device 210 shown in Fig. 2, a rectified input voltage V in when a lightning strike occurs, and a waveform diagram of voltages and currents on the switching device 210 when a lightning strike occurs. As shown in Fig. 3, in the case where a lightning strike occurs when the induction cooker is in operation, the rectified input voltage V in is high, so that the voltage applied across the electromagnetic coil 206 rises, and the slope of the inductor current generated by the electromagnetic coil 206 Increasing; however, due to the hysteresis of the digital control operation, the on-time Ton of the switching device 210 does not change; since the slope of the inductor current generated by the electromagnetic coil 206 increases, the on-time Ton of the switching device 210 ends. When the peak current I pk flowing through the switching device 210 is much larger than the previous period; The voltage V IGBT on the switching device 210 will increase; if the voltage V IGBT on the switching device 210 exceeds its withstand voltage, the switching device 210 will blow up. Even if the MCU senses that the rectified input voltage V in is high by the external input voltage detecting circuit, the MCU is operated, and the operation time of the fastest protection switching device 210 is 1.3 us, and the switching device 210 is disconnected by 1.3us. The latter thing, so using the MCU to over-current protection of the switching device 210 is a bottleneck.

考慮到上述情況，本發明提供了一種通過模擬控制來實現電磁爐的即時雷擊保護的方法。第4圖是示出根據本發明實施例的電磁爐的電子線路系統的電路圖。 In view of the above, the present invention provides a method of realizing instant lightning protection of an induction cooker by analog control. Fig. 4 is a circuit diagram showing an electronic circuit system of an induction cooker according to an embodiment of the present invention.

如第4圖所示，根據本發明實施例的電磁爐的電子線路系統除了包括第2圖所示的電子線路系統200以外，還包括用於以類比控制方式實現電磁爐的即時雷擊保護的控制系統400。 As shown in FIG. 4, the electronic circuit system of the induction cooker according to the embodiment of the present invention includes, in addition to the electronic circuit system 200 shown in FIG. 2, a control system 400 for realizing immediate lightning protection of the induction cooker in an analog control manner. .

在第4圖所示的控制系統400中，比較器Comp 1將輸入 取樣電壓Vac_in與閾值電壓Vth進行比較，以生成表徵是否發生了雷擊事件的第一控制信號，其中輸入取樣電壓Vac_in是通過對交流輸入電壓VAC進行整流分壓後取樣生成的；跨導放大器gm對電流取樣電壓Vcs與參考電壓Vref做差積分，以生成表徵電子線路系統200的輸入功率的功率表徵信號comp，其中電流取樣電壓Vcs是通過對流過電子線路系統200中的開關器件210的電流進行取樣生成的，參考電壓Vref用於表徵電子線路系統200的額定輸入功率；比較器Comp 2將功率表徵信號comp與表徵流過電子線路系統200中的開關器件210的電流的變化速率的速率表徵信號ramp進行比較，以生成第二控制信號，其中速率表徵信號ramp是在電子線路系統200中的開關器件210接通期間生成的；邏輯或器件對第一控制信號與第二控制信號進行邏輯或運算，以生成第一驅動信號；比較器Comp 3將表徵VIGBT變化斜率的電壓與閾值電壓Vth進行比較，以生成第二驅動信號，其中表徵VIGBT變化斜率的電壓是利用電子線路系統200中的開關器件210上的電壓VIGBT生成的；觸發器利用第一驅動信號或者第二驅動信號來驅動電子線路系統200中的開關器件210接通或者斷開。 In the control system 400 shown in FIG. 4, the comparator Comp 1 compares the input sampling voltage Vac_in with a threshold voltage Vth to generate a first control signal indicating whether a lightning strike event has occurred, wherein the input sampling voltage Vac_in is passed The AC input voltage V AC is rectified and divided and sampled; the transconductance amplifier gm differentially integrates the current sampling voltage V cs with the reference voltage V ref to generate a power characterization signal comp characterizing the input power of the electronic circuit system 200, The current sampling voltage V cs is generated by sampling the current flowing through the switching device 210 in the electronic circuit system 200. The reference voltage V ref is used to characterize the rated input power of the electronic circuit system 200; the comparator Comp 2 is used to characterize the signal. The comp is compared to a rate characterization signal ramp that characterizes the rate of change of current flowing through the switching device 210 in the electronic circuit system 200 to generate a second control signal, wherein the rate characterization signal ramp is the switching device 210 in the electronic circuit system 200. Generated during the turn-on; the logic or device logically ORs the first control signal and the second control signal Operator, to generate a first driving signal; comparator Comp 3 V IGBT characterizing the slope of the voltage change of the threshold voltage V th and compared to generate a second drive signal, wherein the change in slope characterizing voltage V IGBT electronics system 200 using The voltage V IGBT on the switching device 210 is generated by the flip-flop; the flip-flop uses the first driving signal or the second driving signal to drive the switching device 210 in the electronic circuit system 200 to be turned on or off.

在一些實施例中，當第一控制信號處於高電平時，表明發生了雷擊事件；當第一控制信號處於低電平時，表明電子線路系統200處於正常工作狀態；當第二控制信號處於高電平時，表明電子線路系統200的輸入電流達到額定功率所需的電流值；當第二控制信號處於低電平時，表明電子線路系統200的輸入電流未上升到額定功率所需的電流值；當第二驅動信號處於高電平時，表明電子線路系統200的VIGBT電壓諧振到谷底即最低值；當第二驅動信號處於低電平時，表明VIGBT電壓未諧振到谷底不能接通開關器件210；當第一驅動信號處於高電平時，觸發器利用第一驅動信號來驅動電子線路系統200中的開關器件210斷開；當第二驅動信號處於高電平時，觸發器利用第二驅動信號來驅動電子線路系統200接通。 In some embodiments, when the first control signal is at a high level, indicating that a lightning strike event occurs; when the first control signal is at a low level, indicating that the electronic circuit system 200 is in a normal operating state; when the second control signal is at a high level Normally, the current value required for the input current of the electronic circuit system 200 to reach the rated power is indicated; when the second control signal is at the low level, the current value required for the input current of the electronic circuit system 200 is not raised to the rated power; When the two driving signals are at a high level, it indicates that the V IGBT voltage of the electronic circuit system 200 resonates to the bottom, that is, the lowest value; when the second driving signal is at the low level, it indicates that the V IGBT voltage does not resonate to the bottom of the valley and cannot turn on the switching device 210; When the first driving signal is at a high level, the flip-flop utilizes the first driving signal to drive the switching device 210 in the electronic circuit system 200 to be turned off; when the second driving signal is at a high level, the flip-flop uses the second driving signal to drive the electron Line system 200 is turned "on".

在一些實施例中，電流取樣電壓Vcs反映了電子線路系統200的輸入電流的大小；在功率表徵信號comp大於或者等於速率表徵信號ramp時，電子線路系統200中的開關器件201接通(即，決定了開關器件210的接通時間Ton)；當電子線路系統200中的開關器件201斷開時，電子線路系統200中的電磁線圈與諧振電容一起發生諧振，當開關器件210上的電壓諧振到谷底時，開關器件210接通。由於電子線路系統200中的電磁線圈的感量與諧振電容的電容大小是不變的，所以諧振週期基本恒定，所以開關器件210上的電壓諧振到谷底的時間(即，開關器件210的斷開時間Toff)基本恒定，只需要調節開關器件210的接通時間Ton來達到設定功率。 In some embodiments, the current sampled voltage V cs reflects the magnitude of the input current of the electronic circuit system 200; a signal indicative of when the power is greater than or equal comp RAMP signal indicative of the rate, the switching device 200 is turned on electronics system 201 (i.e. The on-time Ton of the switching device 210 is determined; when the switching device 201 in the electronic circuit system 200 is turned off, the electromagnetic coil in the electronic circuit system 200 resonates with the resonant capacitor, and the voltage resonance on the switching device 210 When the valley is reached, the switching device 210 is turned on. Since the inductance of the electromagnetic coil in the electronic circuit system 200 and the capacitance of the resonant capacitor are constant, the resonance period is substantially constant, so the time at which the voltage on the switching device 210 resonates to the valley bottom (ie, the disconnection of the switching device 210) The time Toff) is substantially constant, and only the on-time Ton of the switching device 210 needs to be adjusted to reach the set power.

控制系統400可以即時感測輸入取樣電壓Vac_in，當比較器Comp 1感測到雷擊發生時使得開關器件210快速斷開。這主要是因為，在發生雷擊時，整流後的輸入電壓Vin快速升高，電感電流斜率加大，在很短時間內流過開關器件210的電流即衝到開關器件210的額定電流；為了使開關器件210快速斷開，可以感測輸入取樣電壓Vac_in；當輸入取樣電壓Vac_in在任何時候超過閾值保護電壓Vth(例如，雷擊保護閾值)時使得開關器件210斷開，從而避免流過開關器件210的電流衝高。這樣，既保證了流過開關器件210的電流在開關器件210的額定電流範圍內，又保證在接下來開關器件210的斷開時間內諧振電壓不會超過開關器件210的額定電壓。 The control system 400 can sense the input sampling voltage Vac_in instantaneously, causing the switching device 210 to be quickly turned off when the comparator Comp 1 senses that a lightning strike occurs. This is mainly because, in the event of a lightning strike, the rectified input voltage V in rises rapidly, the slope of the inductor current increases, and the current flowing through the switching device 210 in a short time rushes to the rated current of the switching device 210; The switching device 210 is quickly turned off to sense the input sampling voltage Vac_in; when the input sampling voltage Vac_in exceeds the threshold protection voltage Vth (eg, the lightning strike protection threshold) at any time, the switching device 210 is turned off, thereby avoiding flowing through the switching device The current of 210 is high. In this way, it is ensured that the current flowing through the switching device 210 is within the rated current range of the switching device 210, and that the resonant voltage does not exceed the rated voltage of the switching device 210 during the off time of the switching device 210.

由於輸入取樣電壓Vac_in為正弦波，如果雷擊保護閾值為固定值，那麼在輸入取樣電壓Vac_in尚未達到正弦波頂部時發生雷擊的情況下無法及時進行保護，而且不同輸入電壓條件下這個閾值很難設定。所以，在一些實施例中，利用正弦輸入電壓不會發生突變的原理，在電子線路系統200的開關器件210斷開期間的某一固定時刻對輸入取樣電壓Vac_in進行採樣，採樣得到的電壓再疊加一定的直流分量△V，得到雷擊保護閾值Vth_H和/或Vth_L。在發生雷擊時，交流輸入電壓 VAC迅速升高，輸入取樣電壓Vac_in會高於雷擊保護閾值Vth_H，比較器的反映延遲時間在100ns以內，所以能夠快速使開關器件210斷開，保證開關器件210的安全工作。有時，雷擊電壓與交流輸入電壓反向，則輸入取樣電壓Vac_in會低於雷擊保護閾值Vth_L，此時也能快速使開關器件210斷開，保證其安全工作。 Since the input sampling voltage Vac_in is a sine wave, if the lightning strike protection threshold is a fixed value, the lightning protection cannot be performed in time when the input sampling voltage Vac_in has not reached the top of the sine wave, and the threshold is difficult to set under different input voltage conditions. . Therefore, in some embodiments, using the principle that the sinusoidal input voltage does not abruptly, the input sampling voltage Vac_in is sampled at a fixed time during the disconnection of the switching device 210 of the electronic circuit system 200, and the sampled voltage is superimposed. A certain DC component ΔV gives a lightning strike protection threshold Vth_H and/or Vth_L. When a lightning strike occurs, the AC input voltage V AC rises rapidly, the input sampling voltage Vac_in is higher than the lightning strike protection threshold Vth_H, and the reflection delay time of the comparator is within 100 ns, so that the switching device 210 can be quickly disconnected, and the switching device 210 is ensured. Safe work. Sometimes, when the lightning strike voltage is opposite to the AC input voltage, the input sampling voltage Vac_in will be lower than the lightning strike protection threshold Vth_L, and the switching device 210 can be quickly disconnected to ensure safe operation.

下面，將結合第5a-5b圖、以及第6a-6b圖詳細描述確定雷擊保護閾值的具體處理。 Hereinafter, specific processing for determining the lightning strike protection threshold will be described in detail in conjunction with FIGS. 5a-5b and 6a-6b.

第5a圖是示出第4圖中所示的生成第一控制信號的電路部分的另一實施例的電路圖。第5b圖示出了開關器件210的驅動信號、用於控制第5a圖中的開關S1的接通與斷開的S1信號、輸入取樣電壓Vac_in、以及雷擊保護閾值Vth_H和Vth_L的波形圖。結合第5a圖和第5b圖可以看出，經過一個緩衝器隔離輸入取樣電壓Vac_in，然後在開關器件210斷開期間用S1信號對輸入取樣電壓Vac_in進行採樣，採樣得到的電壓減去0.3V得到Vth_L，採樣得到的電壓加上0.3V為Vth_H。當輸入取樣電壓Vac_in高於Vth_H或者低於Vth_L時，輸出高電平的第一控制信號。 Fig. 5a is a circuit diagram showing another embodiment of the circuit portion for generating the first control signal shown in Fig. 4. Fig. 5b shows a waveform diagram of the drive signal of the switching device 210, the S1 signal for controlling the turning on and off of the switch S1 in Fig. 5a, the input sampling voltage Vac_in, and the lightning strike protection thresholds Vth_H and Vth_L. As can be seen from Fig. 5a and Fig. 5b, the input sampling voltage Vac_in is isolated by a buffer, and then the input sampling voltage Vac_in is sampled by the S1 signal during the off period of the switching device 210, and the sampled voltage is subtracted by 0.3V. Vth_L, the sampled voltage plus 0.3V is Vth_H. When the input sampling voltage Vac_in is higher than Vth_H or lower than Vth_L, a first control signal of a high level is output.

第6a圖是示出第4圖中所示的生成第一控制信號的電路部分的又一實施例的電路圖。第6b圖示出了開關器件210的驅動電壓、用於控制第6a圖中的開關S2的接通與斷開的S2信號、以及用於控制第6a圖中的開關S3的接通與斷開的S3信號的波形圖。第5a圖所示的實施例中由於只使用了一個電容，所以如果在S1信號的短脈衝時間內發生雷擊，會錯過感測，不能及時的發生保護。所以，可以採用第6a圖所示的電路，用電容C1記下採樣時刻的電壓作為非採樣時的判斷基準電壓，用電容C2記下採樣前的電壓作為採樣時的判斷基準電壓。判斷基準電壓減去0.3V為雷擊保護閾值Vth_L，判斷基準電壓加上0.3V為雷擊保護閾值Vth_H。當輸入取樣電壓Vac_in高於Vth_H或者低於Vth_L時，輸出高電平的第一控制電壓。 Fig. 6a is a circuit diagram showing still another embodiment of the circuit portion for generating the first control signal shown in Fig. 4. Figure 6b shows the driving voltage of the switching device 210, the S2 signal for controlling the turning on and off of the switch S2 in Fig. 6a, and the switching on and off of the switch S3 in Fig. 6a. Waveform of the S3 signal. In the embodiment shown in Fig. 5a, since only one capacitor is used, if a lightning strike occurs within a short pulse time of the S1 signal, the sensing is missed and the protection cannot be performed in time. Therefore, the circuit shown in Fig. 6a can be used, and the voltage at the sampling time can be recorded by the capacitor C1 as the determination reference voltage at the time of non-sampling, and the voltage before sampling can be recorded by the capacitor C2 as the determination reference voltage at the time of sampling. It is judged that the reference voltage minus 0.3V is the lightning strike protection threshold value Vth_L, and the reference voltage plus 0.3V is the lightning strike protection threshold value Vth_H. When the input sampling voltage Vac_in is higher than Vth_H or lower than Vth_L, a first control voltage of a high level is output.

以上所述的控制系統可適用於各種功率等級的電磁爐，在發生雷擊事件時可以快速使開關器件斷開，從而可以避免開關器件的過流過壓損壞。 The control system described above can be applied to induction cookers of various power levels, and can quickly disconnect the switching device in the event of a lightning strike, thereby avoiding overcurrent and overvoltage damage of the switching device.

本發明可以以其他的具體形式實現，而不脫離其精神和本質特徵。例如，特定實施例中所描述的演算法可以被修改，而系統體系結構並不脫離本發明的基本精神。因此，當前的實施例在所有方面都被看作是示例性的而非限定性的，本發明的範圍由所附申請專利範圍而非上述描述定義，並且，落入申請專利範圍的含義和等同物的範圍內的全部改變從而都被包括在本發明的範圍之中。 The invention may be embodied in other specific forms without departing from the spirit and essential characteristics. For example, the algorithms described in the specific embodiments can be modified, and the system architecture does not depart from the basic spirit of the invention. The present embodiments are to be considered in all respects as illustrative and not limiting, and the scope of the invention All changes in the scope of the invention are thus included in the scope of the invention.

200‧‧‧電子線路系統 200‧‧‧Electronic circuit system

400‧‧‧控制系統 400‧‧‧Control system

VAC‧‧‧交流輸入電壓 V AC ‧‧‧AC input voltage

comp‧‧‧功率表徵信號 Comp‧‧‧Power characterization signal

Vin‧‧‧輸入電壓 V in ‧‧‧ input voltage

ramp‧‧‧速率表徵信號 Ramp‧‧‧ rate characterization signal

Vth‧‧‧閾值電壓 Vth‧‧‧ threshold voltage

VIGBT‧‧‧變化斜率的電壓 V IGBT ‧‧‧Variable slope voltage

Vcs‧‧‧電流取樣電壓 Vcs‧‧‧ current sampling voltage

Vac_in‧‧‧輸入取樣電壓 Vac_in‧‧‧ input sampling voltage

Vref‧‧‧參考電壓 Vref‧‧‧reference voltage

Comp 1、Comp 2、Comp 3‧‧‧比較器 Comp 1, Comp 2, Comp 3‧‧‧ Comparator

gm‧‧‧跨導放大器 Gm‧‧‧transconductance amplifier

Claims (5)

一種用於電磁爐的控制系統，所述電磁爐包括開關器件和電磁線圈，所述開關器件通過不斷地接通與斷開來使所述電磁線圈產生高頻交變磁場，該控制系統包括：開關控制元件，被配置為對所述電磁爐的輸入取樣電壓與閾值電壓進行比較，並根據所述輸入取樣電壓與所述閾值電壓之間的比較結果來控制所述開關器件的接通與斷開，其中，所述輸入取樣電壓是通過對所述電磁爐的交流輸入電壓進行整流分壓後取樣生成的，所述閾值電壓是根據所述輸入取樣電壓產生的；其中，所述開關控制元件還被配置為對所述電磁爐的功率表徵信號與速率表徵信號進行比較，並根據所述功率表徵信號與所述速率表徵信號的比較結果來控制所述開關器件的接通與斷開；其中，所述功率表徵信號用於表徵所述電磁爐的輸入功率並且是通過對電流取樣電壓和參考電壓進行差積分生成的，所述電流取樣電壓是通過對流過所述開關器件的電流進行取樣生成的，所述參考電壓用於表徵所述電磁爐的額定輸入功率，所述速率表徵信號用於表徵流過所述電磁線圈的電流的變化速率。 A control system for an induction cooker, the induction cooker comprising a switching device and an electromagnetic coil, the switching device causing the electromagnetic coil to generate a high frequency alternating magnetic field by continuously turning on and off, the control system comprising: a switch control And an element configured to compare an input sampling voltage of the induction cooker with a threshold voltage, and to control on and off of the switching device according to a comparison result between the input sampling voltage and the threshold voltage, wherein The input sampling voltage is generated by rectifying and dividing the AC input voltage of the induction cooker, and the threshold voltage is generated according to the input sampling voltage; wherein the switch control component is further configured to Comparing a power characterization signal of the induction cooker with a rate characterization signal, and controlling switching on and off of the switching device according to a comparison result of the power characterization signal and the rate characterization signal; wherein the power characterization The signal is used to characterize the input power of the induction cooker and is performed by applying a current sampling voltage and a reference voltage Integral generated, the current sampling voltage is generated by sampling a current flowing through the switching device, the reference voltage is used to characterize a rated input power of the induction cooker, and the rate characterizing signal is used to characterize a flow through The rate of change of the current of the electromagnetic coil. 根據申請專利範圍第1項所述的控制系統，其中，所述開關控制元件還被配置為在所述開關器件開通或斷開期間，利用採樣信號對所述輸入取樣電壓進行採樣並利用採樣結果與預定直流分量的疊加結果作為所述閾值電壓。 The control system of claim 1, wherein the switch control element is further configured to sample the input sampling voltage with a sampling signal and utilize sampling results during the opening or closing of the switching device The result of superposition with a predetermined direct current component is taken as the threshold voltage. 根據申請專利範圍第1項所述的控制系統，其中，所述採樣信號包含第一採樣信號和第二採樣信號，其中所述開關控制元件還被配置為在所述開關器件斷開期間，分別利用所述第一採樣信號和所述第二採樣信號對所述輸入取樣電壓進行採樣，並在非採樣時將利用所述第一採樣信號得到的採樣結果與預定直流分量的疊加結果作為所述閾值電壓，在採樣時將利用所述第二採樣信號得到的採樣結果與所述預定直流分量的疊加結果作為 所述閾值電壓。 The control system of claim 1, wherein the sampling signal comprises a first sampling signal and a second sampling signal, wherein the switching control element is further configured to be disconnected during the opening of the switching device, respectively And sampling the input sampling voltage by using the first sampling signal and the second sampling signal, and using the superimposed result of the sampling result obtained by using the first sampling signal and a predetermined DC component as the a threshold voltage, which is a superposition result of a sampling result obtained by using the second sampling signal and the predetermined DC component at the time of sampling The threshold voltage. 根據申請專利範圍第2或3項所述的控制系統，其中，所述預定直流分量包括正直流分量和負直流分量二者，所述開關控制元件還被配置為分別利用所述正直流分量和所述負直流分量計算所述閾值電壓。 The control system of claim 2, wherein the predetermined direct current component comprises both a positive direct current component and a negative direct current component, the switch control element being further configured to utilize the positive direct current component and The negative DC component calculates the threshold voltage. 根據申請專利範圍第1項所述的控制系統，其中，所述開關控制元件還被配置為在所述輸入取樣電壓大於所述閾值電壓時，斷開所述開關器件。 The control system of claim 1, wherein the switch control element is further configured to open the switching device when the input sampling voltage is greater than the threshold voltage.
TW105107101A 2016-01-13 2016-03-08 Control systems and induction cookers to induction cookers TWI584694B (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201610020531.6A CN105465847A (en) 2016-01-13 2016-01-13 Analog control system for electromagnetic oven and electromagnetic oven

Publications (2)

Publication Number Publication Date
TWI584694B true TWI584694B (en) 2017-05-21
TW201725934A TW201725934A (en) 2017-07-16

Family

ID=55603829

Family Applications (1)

Application Number Title Priority Date Filing Date
TW105107101A TWI584694B (en) 2016-01-13 2016-03-08 Control systems and induction cookers to induction cookers

Country Status (2)

Country Link
CN (2) CN110410834A (en)
TW (1) TWI584694B (en)

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN202111886U (en) * 2011-06-15 2012-01-11 九阳股份有限公司 Induction cooker with IGBT (insulated gate bipolar transistor) overvoltage protection function
TWI362153B (en) * 2008-01-07 2012-04-11 Elan Microelectronics Corp Control circuit for induction heating cooker and induction heating cooker thereof

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5687065A (en) * 1994-11-28 1997-11-11 Philips Electronics North America Corporation Pre-regulator with light switch to limit voltage ringing on turn-off
CN104242658B (en) * 2014-09-19 2017-02-22 无锡芯朋微电子股份有限公司 Valley-switching digital control circuit of switch power source
CN104850165B (en) * 2015-03-16 2017-06-20 昂宝电子（上海）有限公司 Control circuit, control method and its electromagnetic oven for electromagnetic oven
CN104703312B (en) * 2015-03-16 2017-01-04 昂宝电子（上海）有限公司 For the control circuit of electromagnetic oven and control method and electromagnetic oven thereof
CN104850019B (en) * 2015-03-16 2017-11-07 昂宝电子（上海）有限公司 Control circuit and its control method and electromagnetic oven
CN204634075U (en) * 2015-04-30 2015-09-09 佛山市顺德区美的电热电器制造有限公司 Electromagnetic heating system and switching tube thereof open control device

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
TWI362153B (en) * 2008-01-07 2012-04-11 Elan Microelectronics Corp Control circuit for induction heating cooker and induction heating cooker thereof
CN202111886U (en) * 2011-06-15 2012-01-11 九阳股份有限公司 Induction cooker with IGBT (insulated gate bipolar transistor) overvoltage protection function

Also Published As

Publication number Publication date
CN105465847A (en) 2016-04-06
CN110410834A (en) 2019-11-05
TW201725934A (en) 2017-07-16

Similar Documents

Publication Publication Date Title
TWI639361B (en) Induction cooker and control circuit and control method therefor
CN103956900B (en) System and method for the output current regulation in power converting system
JP5753392B2 (en) Method and controller for switch mode power supply
TWI558272B (en) Induction Cooker and control circuit and control method
JP5784317B2 (en) Controller for switch mode power supply and switch mode power supply
CN108633118B (en) Method of operating a transistor, circuit comprising a protection driver and integrated circuit
TWI639360B (en) Control circuit and control method for over-current protection of
WO2016123897A1 (en) Electromagnetic heating control circuit and electromagnetic heating device
TW201101630A (en) Apparatus and method for protection of current sense resistor short circuit in isolated type power supply
TWI596991B (en) A bridgeless circuit and induction cooker for induction cooktops
CN110677018B (en) Control circuit, control method and switching converter
US20230387783A1 (en) Control circuitry for increasing power output in quasi-resonant converters
CN105826899B (en) Excess temperature protection method and switching circuit with overheat protector function
CN103904871B (en) The control method of high-frequency heating power switching tube protection circuit
TWI584694B (en) Control systems and induction cookers to induction cookers
CN112839398B (en) Electromagnetic heating device and dry burning detection method thereof
TW201635851A (en) Control circuit, control method thereof, and induction cooker
CN216434267U (en) Detection circuit and electromagnetic heating control chip for IGBT (insulated Gate Bipolar transistor) conduction step voltage
CN110099469B (en) Electromagnetic induction heating device and protection control circuit thereof
CN109585221B (en) Switch arc extinction control method
WO2018227422A1 (en) Switch-mode power supply and soft-start circuit thereof
TW202236902A (en) Electromagnetic heating system and method
JP6832810B2 (en) Power converter
CN220307419U (en) Resonant power supply voltage regulating circuit for realizing electromagnetic low-power continuous heating
JP5892842B2 (en) Induction heating cooker