CN204539517U - Electromagnetic heating system and switching tube thereof open control device - Google Patents

Abstract

The utility model discloses an electromagnetic heating system and an on-off control device of a switch tube thereof, wherein the on-off control device comprises: a voltage divider circuit, the first input end of the voltage divider circuit is connected with the collector electrode of the switch tube, and the first input end of the voltage divider circuit The two input terminals are connected to the emitter of the switch tube and then grounded, and the voltage divider circuit divides the instantaneous voltage at both ends of the collector and emitter of the switch tube to output the first voltage; the AD converter, the AD converter and the voltage divider circuit The output terminal is connected, and the AD converter converts the first voltage into the first AD value; the main control unit, the main control unit is connected with the drive circuit and the AD converter respectively, and the main control unit obtains the collector and voltage of the switch tube according to the first AD value. The instantaneous voltage at both ends of the emitter is used to adjust the heating power of the electromagnetic heating system so that the switch tube meets the preset opening requirements, so that the switch tube can be intelligently adjusted to the preset opening requirements to better adapt to different pots , to meet the needs of users.

Description

Electromagnetic heating system and its switching tube opening control device

technical field

The utility model relates to the technical field of living appliances, in particular to an opening control device for a switch tube in an electromagnetic heating system and an electromagnetic heating system with the opening control device.

Background technique

In an electromagnetic heating system such as an induction cooker, the ideal state when the power switch IGBT tube is turned on is that Uce' (the voltage between the collector and emitter of the IGBT tube) is zero and the reverse freewheeling current is also zero, but due to actual Due to the limitation of conditions, Uce' cannot oscillate to zero in many cases, especially the smaller the heating power, the harder it is for Uce' to oscillate to zero. At this time, the IGBT is turned on in advance; the reverse freewheeling current is also very low in many cases. Difficult to be zero, the greater the heating power, the greater the reverse freewheeling current may be, and the opening at this time is hysteresis opening.

In the related art, the minimum value and the maximum value of the heating power are generally determined through experiments, so that Uce' is smaller than the preset voltage and the reverse freewheeling current is smaller than the preset current. However, its disadvantage is that Uce' and reverse freewheeling current can only be adjusted to the preset range when using known cookware, and for some unknown cookers, it is impossible to guarantee that Uce' and reverse freewheeling current are both In the preset range, this may cause the IGBT tube to overheat and even cause damage. Therefore, there is a need for improvement in the related art.

Utility model content

The utility model aims to solve one of the technical problems in the related art at least to a certain extent. Therefore, an object of the present utility model is to provide a switch tube opening control device in an electromagnetic heating system, which can intelligently adjust the switch tube to a preset opening requirement, and ensure the switch tube to work safely and reliably.

Another purpose of the utility model is to provide an electromagnetic heating system.

In order to achieve the above object, the utility model proposes a control device for turning on the switch tube in the electromagnetic heating system, wherein the electromagnetic heating system includes a resonant circuit composed of a heating coil, a resonant capacitor and a switch tube, and drives the switch tube The drive circuit, the opening control device includes: a voltage divider circuit, the first input end of the voltage divider circuit is connected to the collector of the switch tube, the second input end of the voltage divider circuit is connected to the switch tube The emitter of the switch is connected to the ground, and the voltage divider circuit divides the instantaneous voltage across the collector and the emitter of the switch tube to output the first voltage; the AD converter, the AD converter and the voltage divider The output terminal of the circuit is connected, and the AD converter converts the first voltage into a first AD value; a main control unit, the main control unit is connected with the driving circuit and the AD converter respectively, and the main control unit The control unit acquires the instantaneous voltage across the collector and emitter of the switch tube according to the first AD value, and adjusts the heating power of the electromagnetic heating system according to the instantaneous voltage across the collector and emitter of the switch tube , so that the switch tube meets a preset turn-on requirement.

According to the opening control device of the switching tube in the electromagnetic heating system proposed by the utility model, the instantaneous voltage at both ends of the collector and the emitter of the switching tube is divided by a voltage dividing circuit to output the first voltage, and the AD converter converts the first The voltage is converted into the first AD value, so that the voltage detection circuit detects the instantaneous voltage across the collector and the emitter of the switch tube, so that the main control unit obtains the instantaneous voltage between the collector and the emitter of the switch tube according to the first AD value, and Adjust the heating power of the electromagnetic heating system according to the instantaneous voltage at both ends of the collector and emitter of the switch tube, so that the switch tube can meet the preset opening requirements, so that the switch tube can be intelligently adjusted to the preset opening requirements, which is better It can adapt to different pots and utensils to meet the needs of users, and can prevent the switch tube from heating or even being damaged due to the advanced or delayed opening, so as to ensure the safe and reliable operation of the switch tube.

Wherein, when the first AD value is greater than a first preset value, the main control unit judges that the switch tube is turned on in advance, and increases the heating power of the electromagnetic heating system; and when the first AD value is less than When the second preset value is reached, the main control unit judges that the switching tube is turned on with a delay, and reduces the heating power of the electromagnetic heating system, wherein the second preset value is smaller than the first preset value.

Specifically, the switch tube is an IGBT tube, the C pole of the IGBT tube is connected to the heating coil and the resonant capacitor connected in parallel, and the C pole of the IGBT tube is connected to the first input end of the voltage divider circuit , the E pole of the IGBT tube is connected to the second input terminal of the voltage divider circuit and then grounded, and the G pole of the IGBT tube is connected to the driving circuit.

Specifically, the voltage dividing circuit includes a first resistor and a second resistor connected in series, a first node is provided between the first resistor and the second resistor connected in series, and the first node is used as the output of the voltage dividing circuit end.

Preferably, the AD converter can be integrated with the main control unit.

In addition, the utility model also proposes an electromagnetic heating system, which includes the above-mentioned opening control device for the switching tube in the electromagnetic heating system.

According to the electromagnetic heating system proposed by the utility model, the switching tube can be intelligently adjusted to the preset opening requirement, which can better adapt to different pots, meet the needs of users, and ensure the safe and reliable operation of the switching tube.

Wherein, the electromagnetic heating system may include an electromagnetic cooker, an electromagnetic rice cooker, and an electromagnetic pressure cooker.

Description of drawings

Fig. 1 is a schematic diagram of an opening control device for a switching tube in an electromagnetic heating system according to an embodiment of the present invention;

Figure 2 is a schematic diagram of voltage and current waveforms when the switch tube is turned on in advance;

Fig. 3 is a schematic diagram of voltage and current waveforms when the switching tube is turned on with hysteresis; and

Fig. 4 is a schematic diagram of an on-off control device for a switching tube in an electromagnetic heating system according to a specific embodiment of the present invention.

Reference signs:

Heating coil L2, resonant capacitor C2, switch tube Q1, resonant circuit 20, drive circuit 30, opening control device 10, voltage divider circuit 101, main control unit 102, AD converter 103, filter inductor L1, filter capacitor C1 and rectifier 40 .

Detailed ways

Embodiments of the present invention are described in detail below, examples of which are shown in the drawings, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the figures are exemplary and are intended to explain the present invention, but should not be construed as limiting the present invention.

The opening control device of the switch tube in the electromagnetic heating system and the electromagnetic heating system with the opening control device proposed by the embodiment of the present invention will be described below with reference to the accompanying drawings, wherein the electromagnetic heating system is used to heat the pan.

Fig. 1 is a schematic diagram of an on-off control device for a switching tube in an electromagnetic heating system according to an embodiment of the present invention. As shown in FIG. 1 , the electromagnetic heating system includes a resonant circuit 20 composed of a heating coil L2 , a resonant capacitor C2 and a switch tube Q1 , and a drive circuit 30 for driving the switch tube Q1 . Wherein, the resonant circuit 20 is used for resonantly heating the pot, specifically, when the switch tube Q1 is turned on under the drive of the drive circuit 30, the heating coil L2 is charged, in order to maintain the connection between the heating coil L2 and the resonant capacitor C2 To prepare for oscillation, when the switch tube Q1 is turned off under the drive of the drive circuit 30, the heating coil L2 and the resonant capacitor C2 oscillate. As a result, an alternating magnetic field is generated around the heating coil L2, and most of the magnetic field lines of the alternating magnetic field pass through the pot and generate a large amount of eddy currents in the bottom of the pot, thereby generating heat required for cooking.

In an embodiment of the present invention, as shown in FIG. 1 , the opening control device 10 includes: a voltage dividing circuit 101 , an AD converter 103 and a main control unit 102 . Wherein, the first input end of the voltage dividing circuit 101 is connected to the collector of the switching tube Q1, the second input end of the voltage dividing circuit 101 is connected to the emitter of the switching tube Q1 and then grounded, and the voltage dividing circuit 101 is connected to the collector of the switching tube Q1. The instantaneous voltage at both ends of the electrode and the emitter is divided to output a first voltage, and the AD converter 103 is connected to the output terminal of the voltage dividing circuit 101 , and the AD converter 103 converts the first voltage into a first AD value. The main control unit 102 is connected to the drive circuit 30 and the AD converter 103 respectively. The main control unit 102 acquires the instantaneous voltage at both ends of the collector and the emitter of the switching tube Q1 according to the first AD value, and obtains the instantaneous voltage at both ends of the collector and the emitter of the switching tube Q1 according to the first AD value. The instantaneous voltage at both ends of the emitter and the emitter adjusts the heating power of the electromagnetic heating system, so that the switch tube Q1 meets the preset turn-on requirement.

That is to say, the main control unit 102 detects the instantaneous voltage across the collector and the emitter of the switch Q1 through the first AD value output by the AD converter 103 to determine whether the switch Q1 is turned on in advance or delayed.

Wherein, the main control unit 102 can output a PWM control signal to the driving circuit 30, so that the driving circuit 30 drives the switch tube Q1 to turn on or off, and the main control unit 102 obtains the collector and emitter of the switch tube according to the first AD value The instantaneous voltage across Uce.

It should be noted that, in the embodiment of the present utility model, the preset turn-on requirement specifically means that the voltage Uce between the collector and the emitter of the switch tube Q1 should be less than or equal to the first voltage when the switch tube Q1 is turned on in advance. The threshold, and the voltage Uce between the collector and the emitter of the switching tube Q1 must be greater than or equal to the second voltage threshold when the switching tube Q1 is turned on with a delay.

It should also be noted that whether the switching tube Q1 meets the preset turning-on requirement when it is turned on is affected by factors such as the pot and the heating power. If the heating power is low, the switching tube Q1 may be turned on in advance; if the heating power is high, the switching tube Q1 may be turned on laggingly. Therefore, the opening control device of the embodiment of the utility model adjusts the heating power so that the switching tube Q1 Meet the preset opening requirements, and then adapt the electromagnetic heating system to different pots.

During the heating process of the electromagnetic heating system, by detecting the instantaneous voltage across the collector and emitter of the switch tube Q1 when the switch tube Q1 is turned on, it can be judged whether the switch tube Q1 is turned on in advance or delayed. When the switch tube Q1 is turned on, the main control unit 102 can obtain the instantaneous voltage across the collector and emitter terminals of the switch tube, and judge whether the switch tube Q1 meets the preset requirements according to the instantaneous voltage across the collector and emitter terminals of the switch tube. Activation requirements. If it is satisfied, keep the current heating power unchanged; if it is not satisfied, that is, the switching tube Q1 is turned on ahead of time or lagging behind, then the heating power needs to be adjusted.

Therefore, the opening control device 10 of the switching tube in the electromagnetic heating system proposed by the embodiment of the utility model adjusts the heating power of the electromagnetic heating system by obtaining the instantaneous voltage at both ends of the collector and the emitter of the switching tube through the first AD value, So that the switching tube Q1 meets the preset opening requirements, so that the switching tube can be intelligently adjusted to the preset opening requirements, which can better adapt to different pots and utensils, meet the needs of users, and prevent the switching tube from being ahead of time. Or lag open and heat even damage.

According to a specific example of the present invention, the main control unit 102 can adjust the heating power by adjusting the duty cycle of the output PWM control signal.

Further, according to an embodiment of the present invention, when the first AD value is greater than a first preset value, the main control unit 102 judges that the switching tube is turned on in advance, and increases the heating power of the electromagnetic heating system; And when the first AD value is less than a second preset value, the main control unit 102 judges that the switching tube is opened with a delay, and reduces the heating power of the electromagnetic heating system, wherein the second preset value is less than the first preset value. It should be noted that the first preset value corresponds to the first voltage threshold, the second preset value corresponds to the second voltage threshold, and the second voltage threshold is smaller than the first voltage threshold, and the second voltage threshold is equal to the first voltage The threshold can be calibrated according to the actual situation of the switching tube.

It should be noted that when the switch tube Q1 is turned on in advance, the voltage Uce between the collector and the emitter of the switch tube Q1 and the waveform of the current Ice flowing through the switch tube Q1 are shown in Figure 2. In an instant, the instantaneous voltage Uce at both ends of the collector and emitter of the switch tube is relatively large, so that the instantaneous voltage Uce1 can be detected. If Uce1 at this time exceeds the first voltage threshold, that is, the first AD value is greater than the first preset value, Then it is judged that the switching tube Q1 is turned on in advance, resulting in a large loss of the switching tube; when the switching tube Q1 is turned on with a delay, the waveform of the voltage Uce between the collector and the emitter of the switching tube Q1 and the current Ice flowing through the switching tube Q1 As shown in Figure 3, when the switch tube is turned on, the instantaneous voltage Uce across the collector and emitter of the switch tube is 0 or a negative value. If Uce2 at this time is less than the second voltage threshold, that is, the first AD value is If the preset value is used, it is judged that the switching tube Q1 is turned on with a delay, and the switching tube will also have a large loss.

As mentioned above, according to the magnitude of the first AD value, the instantaneous voltage Uce across the collector and the emitter of the switch tube can be obtained. When the switch tube Q1 is turned on, that is, when the PWM control signal output by the main control unit 102 changes from a low level to a high level, if the instantaneous voltage across the collector and the emitter of the switch tube is greater than the first voltage threshold, the main control Unit 102 increases the heating power of the electromagnetic heating system to reduce the voltage Uce between the collector and the emitter, so that the voltage Uce drops and reduces the loss of the switch tube, so that the switch tube meets the preset opening requirements, thereby better Adapt to pots and pans. If the instantaneous voltage across the collector and emitter of the switch tube is less than the second voltage threshold, the main control unit 102 reduces the heating power of the electromagnetic heating system, so that the hysteresis loss of the switch tube is reduced, so that the switch tube meets the preset Open the request, so as to better adapt to the pot.

Therefore, the opening control device of the embodiment of the utility model can intelligently adjust the switching tube to the preset opening requirement, better adapt to different pots, meet the needs of users, and can avoid the switching tube due to leading or lagging Turn on and heat up or even damage.

According to a specific embodiment of the present invention, as shown in Figure 4, the heating coil L2 can be connected in parallel with the resonant capacitor C2, the switching tube Q1 can be an IGBT tube, and the C pole of the IGBT tube is connected with the parallel heating coil L2 and the resonant capacitor C2 , and the C pole of the IGBT tube is connected to the first output end of the voltage divider circuit 101 and then grounded, the E pole of the IGBT tube is connected to the second input end of the voltage divider circuit 101 and then grounded, and the G pole of the IGBT tube is connected to the drive circuit 30 .

Further, as shown in FIG. 4 , the electromagnetic heating system may further include a filter inductor L1 , a filter capacitor C1 and a rectifier 40 .

Specifically, one end of the filter inductance L1 is connected to one end of the parallel-connected heating coil L2 and the resonant capacitor C2, wherein, the other end of the parallel-connected heating coil L2 and the resonant capacitor C2 is connected to the C pole of the IGBT tube; the filter capacitor C1 One end is connected to one end of the filter inductor L1, and the other end of the filter capacitor C1 is grounded; the first input end of the rectifier 40 is connected to the live line L of the AC power supply AC, and the second input end of the rectifier 40 is connected to the neutral line N of the AC power supply AC. The first output end of the rectifier 40 is connected to the other end of the filter inductor L1, and the second output end of the rectifier 40 is grounded.

Moreover, as shown in FIG. 4 , the voltage divider circuit 101 includes a first resistor R1 and a second resistor R2 connected in series, and a first node J1 is located between the first resistor R1 and the second resistor R2 connected in series, and the first node J1 serves as a divider. The output terminal of voltage circuit 101 is connected with AD converter 103 .

According to an embodiment of the present invention, as shown in FIG. 4 , the AD converter 103 can also be integrated with the main control unit 102 , for example, the AD converter 103 is integrated in the main control unit 102 .

According to the opening control device of the switching tube in the electromagnetic heating system proposed by the embodiment of the present invention, the instantaneous voltage at both ends of the collector and the emitter of the switching tube is divided by the voltage dividing circuit to output the first voltage, and the AD converter will The first voltage is converted into the first AD value, so that the voltage detection circuit detects the instantaneous voltage across the collector and emitter of the switch tube, so that the main control unit obtains the instantaneous voltage across the collector and emitter of the switch tube according to the first AD value , and adjust the heating power of the electromagnetic heating system according to the instantaneous voltage across the collector and emitter of the switch tube, so that the switch tube meets the preset opening requirements, so that the switch tube can be intelligently adjusted to the preset opening requirements. It can better adapt to different pots and utensils, meet the needs of users, and can prevent the switch tube from heating or even being damaged due to the early or late opening, so as to ensure the safe and reliable operation of the switch tube.

In addition, the embodiment of the present utility model also proposes an electromagnetic heating system, which includes the switch tube turn-on control device described in the above embodiments.

Wherein, the electromagnetic heating system may include an electromagnetic cooker, an electromagnetic rice cooker, an electromagnetic pressure cooker, and the like.

According to the electromagnetic heating system proposed by the embodiment of the utility model, the switching tube can be intelligently adjusted to the preset opening requirement, which can better adapt to different pots, meet the needs of users, and ensure the safe and reliable operation of the switching tube.

In describing the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "Back", "Left", "Right", "Vertical", "Horizontal", "Top", "Bottom", "Inner", "Outer", "Clockwise", "Counterclockwise", "Axial" The orientation or positional relationship indicated by , "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the utility model and simplifying the description, rather than indicating or implying the referred device Or elements must have a specific orientation, be constructed and operate in a specific orientation, and thus should not be construed as limiting the invention.

In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be interpreted as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include at least one of these features. In the description of the present utility model, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

In this utility model, unless otherwise specified and limited, terms such as "installation", "connection", "connection" and "fixation" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection. Connected, or integrated; may be mechanically or electrically connected; may be directly connected or indirectly connected through an intermediary, and may be an internal communication between two elements or an interactive relationship between two elements, unless otherwise stated Clearly defined. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present utility model according to specific situations.

In the present invention, unless otherwise clearly specified and limited, the first feature may be in direct contact with the first feature or the first feature and the second feature through an intermediary indirect contact. Moreover, "above", "above" and "above" the first feature on the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. "Below", "beneath" and "beneath" the first feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is less horizontally than the second feature.

In the description of this specification, descriptions referring to the terms "one embodiment", "some embodiments", "example", "specific examples", or "some examples" mean that specific features described in connection with the embodiment or example , structures, materials or features are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the described specific features, structures, materials or characteristics may be combined in any suitable manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples and features of different embodiments or examples described in this specification without conflicting with each other.

Although the embodiments of the present invention have been shown and described above, it can be understood that the above-mentioned embodiments are exemplary and should not be construed as limitations of the present invention, and those skilled in the art are within the scope of the present invention. Variations, modifications, substitutions and variations can be made to the above-described embodiments.

Claims (7)

1. A switch-on control device for a switching tube in an electromagnetic heating system, characterized in that, the electromagnetic heating system includes a resonant circuit made up of a heating coil, a resonant capacitor and a switching tube and a drive circuit for driving the switching tube, the Activation controls include: A voltage divider circuit, the first input end of the voltage divider circuit is connected to the collector of the switch tube, the second input end of the voltage divider circuit is connected to the emitter of the switch tube and then grounded, the voltage divider The circuit divides the instantaneous voltage across the collector and the emitter of the switching tube to output a first voltage; an AD converter, the AD converter is connected to the output terminal of the voltage divider circuit, and the AD converter converts the first voltage into a first AD value; A main control unit, the main control unit is connected to the drive circuit and the AD converter respectively, and the main control unit acquires the instantaneous voltage across the collector and the emitter of the switching tube according to the first AD value , and adjust the heating power of the electromagnetic heating system according to the instantaneous voltage across the collector and the emitter of the switch tube, so that the switch tube meets a preset turn-on requirement. 2. the opening control device of switching tube in the electromagnetic heating system as claimed in claim 1, it is characterized in that, When the first AD value is greater than a first preset value, the main control unit judges that the switching tube is turned on in advance, and increases the heating power of the electromagnetic heating system; and When the first AD value is less than a second preset value, the main control unit judges that the switching tube is turned on with delay, and reduces the heating power of the electromagnetic heating system, wherein the second preset value is less than the first preset value. 3. The opening control device of the switch tube in the electromagnetic heating system as claimed in claim 1, wherein the switch tube is an IGBT tube, and the C pole of the IGBT tube is connected to the parallel connection of the heating coil and the resonant capacitor , and the C pole of the IGBT tube is connected to the first input end of the voltage divider circuit, the E pole of the IGBT tube is connected to the second input end of the voltage divider circuit and then grounded, and the G pole of the IGBT tube is connected to the second input end of the voltage divider circuit. connected to the drive circuit. 4. The opening control device of the switching tube in the electromagnetic heating system as claimed in claim 1, wherein the voltage divider circuit includes a first resistor and a second resistor connected in series, and the first resistor connected in series and the second resistor connected in series There is a first node between the resistors, and the first node serves as the output terminal of the voltage dividing circuit. 5. The device for controlling the switching on of the switching tube in the electromagnetic heating system according to claim 1, wherein the AD converter can be integrated with the main control unit. 6. An electromagnetic heating system, characterized in that it comprises the opening control device of the switching tube in the electromagnetic heating system according to any one of claims 1-5. 7. The electromagnetic heating system according to claim 6, wherein the electromagnetic heating system comprises an electromagnetic cooker, an electromagnetic rice cooker, and an electromagnetic pressure cooker.