Search

KR-20260066742-A - Discharge circuit

KR20260066742AKR 20260066742 AKR20260066742 AKR 20260066742AKR-20260066742-A

Abstract

An anode discharge circuit (1) for an induction cooking zone (Z) for detecting and heating a cooking appliance (W) comprises: a line main power terminal (T1) connected to the main power line (L) of a main power AC source (2) and a neutral main power terminal (T2) connected to the main power neutral line (N) of the main power AC source (2); a rectifier (3) connected to the line main power terminal (T1) and the neutral main power terminal (T2); and a DC bus capacitor (6) connected to the rectifier (3). The DC bus capacitor (6) comprises a positive capacitor terminal (H1) and a negative capacitor terminal (H2) connected to the induction cooking zone (Z). A switching circuit (9) configured to discharge the DC bus capacitor (6) through the line main power terminal (T1) and the neutral main power terminal (T2) is provided.

Inventors

  • 후프밋, 마르셀
  • 자이츠, 안제
  • 트르잔, 사이먼

Assignees

  • 인텔 프로퍼티스 비.브이.

Dates

Publication Date
20260512
Application Date
20240820
Priority Date
20230829

Claims (13)

  1. As an anode discharge circuit (1) for an induction cooking zone (Z) for detecting and heating a cooking appliance (W), A line main power terminal (T1) connected to the main power line (L) of the main power AC supply source (2) and a neutral line main power terminal (T2) connected to the main power neutral line (N) of the main power AC supply source (2); A rectifier (3) having a line connection part (4a) connected to the above-mentioned line main power terminal (T1), a neutral line connection part (4b) connected to the above-mentioned neutral line main power terminal (T2), and a positive DC connection part (5a) and a negative DC connection part (5b); A DC bus capacitor (6) having a positive capacitor terminal (H1) and a negative capacitor terminal (H2), wherein the positive capacitor terminal (H1) is connected to the positive DC connection part (5a) through a positive DC line (7), and the negative capacitor terminal (H2) is connected to the negative DC connection part (5b) through a negative DC line (8), and the positive capacitor terminal (H1) and the negative capacitor terminal (H2) are configured to be connected to an induction cooking zone (Z) to detect and heat a cooking appliance (W); and A switching circuit (9) comprising a first main discharge connection (10a) connected to the positive DC line (7) and a second main discharge connection (10b) connected to the negative DC line (8), a first positive wave cycle connection (11a) connected to the line main power terminal (T1) and a second positive wave cycle connection (11b) connected to the neutral line main power terminal (T2), and a first negative wave cycle connection (12a) connected to the neutral line main power terminal (T2) and a second negative wave cycle connection (12b) connected to the line main power terminal (T1), wherein the switching circuit (9) A first switching state in which the above DC bus capacitor (6) can be discharged through the first positive wave period connection (11a) and the second positive wave period connection (11b); A second switching state in which the above DC bus capacitor (6) can be discharged through the first negative wave cycle connection (12a) and the second negative wave cycle connection (12b); A positive discharge circuit configured to provide a third switching state in which the DC bus capacitor (6) is separated from the first positive wave cycle connection (11a), the second positive wave cycle connection (11b), the first negative wave cycle connection (12a), and the second negative wave cycle connection (12b).
  2. In claim 1, in the first switching state, the first main discharge connection (10a) is connected to the first positive wave period connection (11a), and the second main discharge connection (10b) is connected to the second positive wave period connection (11b), and the first main discharge connection (10a) is separated from the first negative wave period connection (12a), and the second main discharge connection (10b) is separated from the second negative wave period connection (12b); In the second switching state, the first main discharge connection (10a) is connected to the first negative wave cycle connection (12a), and the second main discharge connection (10b) is connected to the second negative wave cycle connection (12b); the first main discharge connection (10a) is separated from the first positive wave cycle connection (11a), and the second main discharge connection (10b) is separated from the second positive wave cycle connection (11b); A positive discharge circuit in which, in the third switching state, the first main discharge connection (10a) is separated from the first positive wave cycle connection (11a) and the first negative wave cycle connection (12a), and the second main discharge connection (10b) is separated from the second positive wave cycle connection (11b) and the second negative wave cycle connection (12b).
  3. In claim 1 or 2, the first switching state continues for a positive wave period (TP) of the main power AC supply (2), and the second switching state continues for a negative wave period (TN) of the main power AC supply (2); The above positive wave period (TP) is defined as starting when the line main power terminal (T1) is at a predetermined first positive voltage and ending when the line main power terminal (T1) reaches a predetermined second positive voltage, wherein the first positive voltage is higher than the second positive voltage; The above negative wave period (TN) is defined as starting when the line main power terminal (T1) is at a predetermined first negative voltage and ending when the line main power terminal (T1) reaches a predetermined second negative voltage, wherein the first negative voltage is lower than the second negative voltage, a positive discharge circuit.
  4. In paragraph 3, the positive wave period (TP) is further defined as starting between T/4 and 1.2*T/4 of the period (T) of the single sinusoidal wave of the AC source (2) when measured with respect to the first zero crossing point (ZC1), and ending when the DC capacitor voltage (Vdc) across the positive capacitor terminal (H1) and the negative capacitor terminal (H2) is 0 V to 30 V; An anode discharge circuit further defined such that the above negative wave period (TN) starts between T/4 and 1.2*T/4 of the above period (T) when measured with respect to the second zero crossing point (ZC2) and ends when the DC capacitor voltage (Vdc) across the above positive capacitor terminal (H1) and the above negative capacitor terminal (H2) is 0 V to 30 V.
  5. In paragraph 4, an anode discharge circuit in which T = 1/50 millisecond or T = 1/60 millisecond.
  6. In any one of claims 1 to 5, the switching circuit (9) comprises a positive period switching portion (S+) including a first positive wave period connection portion (11a), a second positive wave period connection portion (11b), a first positive discharge connection portion (13a) connected to the first main discharge connection portion (10a), and a second positive discharge connection portion (13b) connected to the second main discharge connection portion (10b). The above positive period switching portion (S+) can be switched to discharge the DC bus capacitor (6) through the first positive discharge connection (13a), the first positive wave period connection (11a), the second positive wave period connection (11b), and the second positive discharge connection (13b); The switching circuit (9) further comprises a negative period switching portion (S-) including the first negative wave period connection portion (12a), the second negative wave period connection portion (12b), the first negative discharge connection portion (14a) connected to the first main discharge connection portion (10a), and the second negative discharge connection portion (14b) connected to the second main discharge connection portion (10b). The above negative period switching portion (S-) is a positive discharge circuit that can be switched to discharge the DC bus capacitor (6) through the first negative discharge connection portion (14a), the first negative wave period connection portion (12a), the second negative wave period connection portion (12b), and the second negative discharge connection portion (14b).
  7. In claim 6, the positive period switching portion (S+) comprises a first positive switch (15) for connecting the first positive wave period connection portion (11a) to the first positive discharge connection portion (13a), a second positive switch (16) for connecting the second positive wave period connection portion (11b) to the second positive discharge connection portion (13b), and a positive logic circuit (17) configured to switch the first positive switch (15) and the second positive switch (16); The above negative period switching portion (S-) comprises a first negative switch (18) for connecting the first negative wave period connection portion (12a) to the first negative discharge connection portion (14a), a second negative switch (19) for connecting the second negative wave period connection portion (12b) to the second negative discharge connection portion (14b), and a negative logic circuit (20) configured to switch the first negative switch (18) and the second negative switch (19), a positive discharge circuit.
  8. A positive discharge circuit according to claim 7, wherein the first positive switch (15) and the first negative switch (18) are each TRIACs, and the second positive switch (16) and the second negative switch (19) are each MOSFETs.
  9. An anode discharge circuit having the same circuit device, wherein in any one of claims 6 to 8, the positive periodic switching portion (S+) and the negative periodic switching portion (S-) are the same circuit device.
  10. A positive discharge circuit according to any one of claims 7 to 9, wherein the switching circuit (9) further comprises a resistor (20) connected to the second positive discharge connection (13b), the second negative discharge connection (14b), and the second main discharge connection (10b), and further comprises a protection circuit (21) configured to measure the current passing through the resistor (20) and, based on the measured current, open the first positive switch (15) and the second positive switch (16) or open the first negative switch (18) and the second negative switch (19).
  11. An induction cooking hob comprising an anode discharge circuit (1) and an induction cooking zone (Z) according to any one of claims 1 to 10, The above induction cooking zone (Z) is an induction cooking hob connected to the positive capacitor terminal (H1) and the negative capacitor terminal (H2) of the above positive discharge circuit (9).
  12. A method of operating an anode discharge circuit (1) according to any one of claims 1 to 10, A step of connecting the line main power terminal (T1) to the main power line (L) of the main power AC supply source (2); A step of connecting the neutral wire main power terminal (T2) to the main power neutral wire (N) of the above main power AC supply source (2); A step of connecting a positive capacitor terminal (H1) and a negative capacitor terminal (H2) to an induction cooking zone (Z); and A method comprising the step of sequentially switching a switching circuit (9) to a first switching state and a second switching state before activating the induction cooking zone (Z) to detect or heat the cooking appliance (W), and then activating the induction cooking zone (Z) to detect or heat the cooking appliance (W).
  13. In claim 12, the step of switching the switching circuit (9) to the first switching state comprises the step of discharging the DC bus capacitor (6) through the first positive wave cycle connection (11a) and the second positive wave cycle connection (11b) when the main power AC voltage (Vm) of the line main power terminal (T1) is placed between a predetermined first positive voltage and a predetermined second positive voltage, wherein the first positive voltage is higher than the second positive voltage; The step of switching the switching circuit (9) to the second switching state comprises the step of discharging the DC bus capacitor (6) through the first negative wave cycle connection (12a) and the second negative wave cycle connection (12b) when the main power AC voltage (Vm) of the line main power terminal (T1) is placed between a predetermined first negative voltage and a predetermined second negative voltage, wherein the first negative voltage is lower than the second negative voltage.

Description

Discharge circuit The present invention relates to a discharge circuit, and more particularly to an anode discharge circuit for an induction cooking zone. International patent application WO 2022/096122 A1 discloses a circuit device for discharging an intermediate circuit capacitor for an induction coil of a cooking hob to reduce a peak current in the circuit during discharge. The circuit device discharges the intermediate circuit capacitor for a predetermined period during which the mains voltage has a positive value between two zero crossing points using a separate discharge circuit. European patent application EP 3 768 042 A1 discloses a system and method for controlling the power supply to an induction coil of an induction hob. The system comprises an input portion for receiving a rectified AC voltage, at least one switching element for supplying pulsed power to an induction coil, a capacitor connected in parallel with the switching element, and a discharge element configured to enable the discharge of the capacitor. The system further comprises a control element configured to perform a successive control cycle, wherein in the control cycle, the control element discharges the capacitor based on the discharge element and, after the discharge of the capacitor, is configured to start the switching operation of the switching element to supply pulsed power to the induction coil. The present invention is discussed in more detail below with reference to the accompanying drawings. FIG. 1 illustrates an anode discharge circuit connected to a main power AC supply and an induction cooking zone according to an embodiment of the present invention. FIG. 2 illustrates an example of the operation and switching state of an anode discharge circuit for a main power AC voltage according to an embodiment of the present invention. FIGS. 3a and 3b illustrate a positive periodic switching portion and a negative periodic switching portion used by an anode discharge circuit according to an embodiment of the present invention. FIG. 1 illustrates a positive discharge circuit (1) connected to a main power AC source (2) and an induction cooking zone (Z) according to an embodiment of the present invention. The main power AC source (2) may be considered as a typical main power AC power socket found in residential buildings, commercial buildings, etc., and the main power AC source (2) may operate at, for example, 230 V, 50 Hz or 120 V, 60 Hz depending on the geographical location. The induction cooking zone (Z) may be a standard or well-known induction cooking zone (Z). As illustrated, an exemplary induction cooking zone (Z) includes a resonant circuit using, for example, a zone capacitor (C) and a zone inductor (L) in parallel, and the zone inductor (L) is positioned to magnetically interact with the cooking appliance (W) for sensing or heating. The resonant circuit including the zone capacitor (C) and the zone inductor (L) may be operated by an IGBT switch device (G). However, it is noted that the induction cooking zone (Z) can use different circuit topologies, such as a half-bridge topology. As additionally illustrated in FIG. 1, the positive switching circuit (1) includes a line main power terminal (T1) connected to the main power line (L) of the main power AC supply source (2) and a neutral main power terminal (T2) connected to the main power neutral line (N) of the main power AC supply source (2). The main power line terminal (T1) and the neutral main power terminal (T2) can be configured or adjusted to be connected to a standard main power AC power socket. The positive switching circuit (1) further includes a rectifier (3) having a line connection part (4a) connected to a line main power terminal (T1) and a neutral line connection part (4b) connected to a neutral line main power terminal (T2), and further includes a positive (+) DC connection part (5a) and a negative (-) DC connection part (5b). Additionally, a DC bus capacitor (6) is provided, comprising a positive capacitor terminal (H1) and a negative capacitor terminal (H2), wherein the positive capacitor terminal (H1) is connected to a positive DC connection (5a) via a positive DC line (7), and the negative capacitor terminal (H2) is connected to a negative DC connection (5b) via a negative DC line (8). As illustrated in FIG. 1, in an exemplary embodiment, the negative DC line (8) is grounded. Subsequently, the positive capacitor terminal (H1) and the negative capacitor terminal (H2) are configured to be connected to an induction cooking zone (Z) to detect and heat a cooking appliance (W). In another embodiment, it should be noted that the positive discharge circuit (1) includes an additional DC bus capacitor (6') having an additional positive capacitor terminal (H1') and an additional negative capacitor terminal (H2'), and that the additional positive capacitor terminal (H1') is connected to a positive DC connection (5a) via a positive DC line (7), and the additional negat