Container Detection Method for Integrated Half-Bridge Inverter Electric Range

Abstract

The present invention relates to a container detection method for an integrated half-bridge inverter electric range, and more specifically, to a container detection method for an integrated half-bridge inverter electric range that can detect the presence or absence of a container even when the input voltage applied to the electric range is different. A container detection method for an integrated half-bridge inverter electric range according to the present invention comprises an input voltage measurement step, an input value comparison step, a correction step, an output voltage measurement step, and a determination step. The input voltage measurement step measures an input voltage input to the electric range. The input value comparison step compares the input voltage with a preset reference input voltage. The correction step corrects the on-time of the input voltage of the upper IGBT element of the electric range based on the on-time of the reference input voltage when the input voltage differs from the reference input voltage in the input value comparison step. The output voltage measurement step measures the output voltage output from the electric range after the correction step. The determination step determines that there is a container in the electric range if the output voltage measured in the output voltage measurement step is greater than a preset container determination value. According to the present invention, even if the input voltage applied to the electric range changes, by correcting the on-time of the upper IGBT element at the input voltage based on the on-time of the upper IGBT element at the reference input voltage, it is possible to determine whether a container is placed on the electric range without being affected by the input voltage.

Description

Technology Field

[0001] The present invention relates to a container detection method for an integrated half-bridge inverter electric range, and more specifically, to a container detection method for an integrated half-bridge inverter electric range that can detect the presence or absence of a container even when the input voltage applied to the electric range is different. Background Technology

[0002] Induction electric cooktops heat cookware using electromagnetic induction. When current is sent to the working coil located beneath the cooktop, a magnetic field is generated, and as this magnetic field passes through the cookware placed on the cooktop, it creates eddy currents. These eddy currents transfer heat to the cookware itself, thereby facilitating cooking.

[0003] At this time, if a pot or container intended for heating is placed on even a part of the working coil, the working coil starts heating and heats the container. Even if other objects that can be heated by induced current, such as chopsticks or tongs, are placed on the upper cooking area of ​​the working coil of the induction electric range in addition to the container intended for heating, they are recognized as containers intended for heating and can be heated.

[0004] Therefore, conventional induction electric ranges apply a container detection method so that the container can be heated only when a dedicated container is properly placed on top of the working coil.

[0005] A half-bridge inverter converts direct current (DC) into high-frequency alternating current (AC) and supplies it to the working coil. The working coil then generates a magnetic field, and the container absorbs this magnetic field, generating eddy currents and heat. At this time, the amount of magnetic field consumed varies depending on the size, material, and position of the container placed thereon, and this acts as a load on the working coil. Therefore, if only a portion of the container is placed above the working coil or if other materials such as chopsticks are placed thereon, the load is low, so the absorption of the magnetic field is small, and the output voltage remains low.

[0006] Therefore, conventional container detection methods measure the output voltage and detect the presence of a container only when the output voltage is higher than a preset reference value. Prior art literature

[0007] Published Patent No. 10-2019-0112981 (Publication Date: October 08, 2019) Registered Patent No. 10-1718878 (Registration Date: March 16, 2017) Registered Patent No. 10-2280673 (Registration Date: July 16, 2021) The problem to be solved

[0008] When power is input to an electric range, it is not always constant. For example, even when using 220V power, the input is not always 220V; depending on the situation, a voltage higher or lower than 220V may be input. However, the output voltage of the electric range varies depending on the input voltage.

[0009] In other words, even if the same dedicated container is placed on the electric range, the output voltage changes if the input voltage changes. However, the reference value for the output voltage used to determine whether a dedicated container is placed on the electric range is set based on a constant input voltage. For example, based on an input voltage of 220V, the presence of the container is determined by the output voltage.

[0010] In this case, the input voltage is not 220V but may vary, so even if a dedicated container is placed on the electric range, the output voltage will be different.

[0011] Therefore, since the output voltage varies depending on the input voltage of the electric range, there was a problem in that the container could not be properly detected when the reference value was constant.

[0012] The present invention aims to solve the above-mentioned problems. The present invention aims to provide a container detection method capable of accurately determining the presence or absence of a container even when the input voltage differs from the reference input voltage during container detection in an integrated half-bridge inverter electric range. means of solving the problem

[0013] A container detection method for an integrated half-bridge inverter electric range according to the present invention comprises an input voltage measurement step, an input value comparison step, a correction step, an output voltage measurement step, and a determination step. The input voltage measurement step measures an input voltage input to the electric range. The input value comparison step compares the input voltage with a preset reference input voltage. The correction step corrects the on-time of the input voltage of the upper IGBT element of the electric range based on the on-time of the reference input voltage when the input voltage differs from the reference input voltage in the input value comparison step. The output voltage measurement step measures the output voltage output from the electric range after the correction step. The determination step determines that there is a container in the electric range if the output voltage measured in the output voltage measurement step is greater than a preset container determination value.

[0014] In addition, in the container detection method of the integrated half-bridge inverter electric range described above, the correction step preferably calculates the on-time of the reference input voltage to be inversely proportional to the rate of increase or decrease of the input voltage relative to the reference input voltage, and then corrects the on-time of the input voltage to the on-time calculated to be inversely proportional. Effects of the invention

[0015] According to the present invention, even if the input voltage applied to the electric range changes, by correcting the on-time of the upper IGBT element at the input voltage based on the on-time of the upper IGBT element at the reference input voltage, it is possible to determine whether a container is placed on the electric range without being affected by the input voltage. Brief explanation of the drawing

[0016] FIG. 1 is a conceptual diagram of one embodiment of a container detection method for an integrated half-bridge inverter electric range according to the present invention. FIG. 2 is a conceptual diagram for correcting the on-time of the embodiment illustrated in FIG. 1. Specific details for implementing the invention

[0017] An embodiment of a container detection method for an integrated half-bridge inverter electric range according to the present invention will be described with reference to FIGS. 1 and 2.

[0018] The container detection method of an electric range according to the present invention includes an input voltage measurement step (S11), an input value comparison step (S13), a correction step (S15), an output voltage measurement step (S17), and a determination step (S19).

[0019] The input voltage measurement step (S11) measures the input voltage input to the electric range.

[0020] A half-bridge inverter converts direct current (DC) into high-frequency alternating current (AC) and supplies it to the working coil. The working coil generates a magnetic field, and the container absorbs this field, producing eddy currents and heat, which act as a load on the working coil. Therefore, when a container is placed, it absorbs the magnetic field, increasing the load on the working coil. As the load increases, the system attempts to supply more power to offset this, causing the output voltage to rise. In other words, the output voltage differs depending on whether a container is placed on the working coil or not. Thus, it is possible to determine whether a container is placed on the working coil by measuring the output voltage.

[0021] However, since the consumption of the magnetic field varies depending on the size, material, and position of the container placed on the working coil, and the output voltage varies depending on whether the container is placed correctly or if a material other than the container is placed, a certain container detection value is set to determine whether the container is placed correctly. If the output voltage is output above the container detection value, it is possible to determine whether a container is placed.

[0022] Meanwhile, when a container is placed, the output voltage varies depending on the magnitude of the input voltage. That is, even if the same container is placed on the working coil, it differs depending on whether the input voltage is 220V, 275V, or 165V. When the input voltage is 275V, the output voltage is higher than when it is 220V, and when it is 165V, the output voltage is lower than when it is 220V.

[0023] Even when the standard input voltage is 220V, if the input voltage is unstable, a voltage higher or lower than 220V may be input, which presents a problem in that the container cannot be accurately identified. Therefore, to determine whether a container is placed, the input voltage must be measured and corrected accordingly.

[0024] The input value comparison step (S13) compares the input voltage with a preset reference input voltage. For example, the input voltage is compared with 220V.

[0025] In the correction step (S15), when the input voltage and the reference input voltage differ in the input value comparison step (S13), the microcontroller of the electric range corrects the On Time of the upper IGBT element at the input voltage based on the On Time when the reference input voltage is different. At this time, the On Time of the reference input voltage is calculated to be inversely proportional to the rate of increase or decrease of the input voltage relative to the reference input voltage, and then the On Time of the actual input voltage is corrected to the On Time calculated to be inversely proportional.

[0026] For example, the frequency of the input voltage consists of the on time (3) of the upper IGBT element, the on time (7) of the lower IGBT element, and the dead time (5), and Figure 2 (a) is when the input voltage is 220V.

[0027] At this time, if the input voltage is 165V, the output voltage is lowered. In this case, the on-time (3) of the upper IGBT element is corrected as shown in Fig. 2(b). That is, since the input voltage has decreased by 30% compared to 220V, the on-time (3) of the upper IGBT element is corrected to increase by 30% compared to the on-time when it is 220V. And if the input voltage is 275V, the output voltage is higher. In this case, the on-time (3) of the upper IGBT element is corrected as shown in Fig. 2(c). That is, since the input voltage has increased by 30% compared to 220V, the on-time (3) of the upper IGBT element is corrected to decrease by 30% compared to the on-time when it is 220V.

[0028] The "On Time" of the upper IGBT refers to the duration that the upper IGBT, a key component controlling power in an electric range, remains turned on. As this time increases, more power is supplied, resulting in a higher output voltage; conversely, as it decreases, the output voltage decreases. Therefore, if the On Time increases—that is, if the upper IGBT remains on for a longer period—more current flows through the coil, generating a stronger magnetic field. This magnetic field induces eddy currents in the container to generate heat, which increases the output voltage and produces the effect of a brighter flame. Conversely, if the On Time decreases—that is, if the upper IGBT remains on for only a short time—the current flowing through the coil decreases, the magnetic field weakens, and the output voltage drops. Consequently, by measuring the input voltage and correcting for any discrepancies with the reference input voltage using the On Time of the upper IGBT, the power output can be matched to that of the reference input voltage.

[0029] The output voltage measurement step (S17) measures the output voltage of the electric range after the correction step (15).

[0030] The determination step (S19) determines that there is a container in the electric range if the output voltage measured in the output voltage measurement step (S13) is greater than a preset container determination value.

[0031] Therefore, according to the present embodiment, even if the input voltage changes, the presence or absence of the container can be accurately determined by making corrections accordingly. Explanation of the symbols

[0032] 1 : Frequency 3: Top IGBT device on time 5 : Dead Time 7: Bottom IGBT device on time

Claims

Claim 1 A container detection method for an integrated half-bridge inverter electric range, characterized by comprising: an input voltage measurement step for measuring an input voltage input to an electric range; an input value comparison step for comparing the input voltage with a preset reference input voltage; a correction step for correcting the on time of the input voltage of an upper IGBT element of the electric range based on the on time of the reference input voltage when the input voltage differs from the reference input voltage in the input value comparison step; an output voltage measurement step for measuring an output voltage output from the electric range after the correction step; and a determination step for determining that there is a container in the electric range if the output voltage measured in the output voltage measurement step is greater than a preset container determination value. Claim 2 A container detection method for an integrated half-bridge inverter electric range, wherein, in claim 1, the correction step calculates the on-time of the reference input voltage to be inversely proportional to the rate of increase or decrease of the input voltage relative to the reference input voltage, and then corrects the on-time of the input voltage to the on-time calculated to be inversely proportional.

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