JP2006278192A - Induction heating cooker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an induction heating cooker capable of preventing overload of indoor wiring and capable of outputting desired calories even if it is used in single-phase 100 V. <P>SOLUTION: An induction heating part driving device 12 acquires a direct current electric power by rectifying an alternate current electric power from a commercial alternate current power supply 16, and converts that direct current electric power to a high frequency electric power and supplies it to an induction heating part 11. Moreover, an arithmetic control circuit 15 controls switching elements S1, S2, S3 of the induction heating part driving device, and when electric power consumption at the induction heating part 11 is zero or less, it stores the electric power from the alternate current power supply in a battery 13, and when the electric power consumption at the induction heating part 11 is deficient only by the alternate current power supply, it controls to supply the shortfall to the induction heating part 11 within a range not exceeding a battery supply limit electric power. Moreover, the arithmetic control circuit 15 calculates driving operable time of the battery 13, and displays it on an operation display part 14. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an induction heating cooker that can output a desired amount of heat even with a commercial AC power supply.

  IH (Induction Heating) cooking heater (induction heating cooker), one of the high power home appliances, obtains DC power by rectifying AC power from AC power supply, converts the DC power to high frequency power, induction heating unit To generate heat by induction heating (IH). Such an induction heating cooker generally requires a single-phase 200V AC power supply. On the other hand, in a general household, the power lead-in wire is drawn in by single-phase three-wire, but a single-phase 200V outlet is not prepared indoors, particularly in the kitchen. Therefore, when an induction heating cooker is to be introduced, a new construction work for indoor wiring is required, which is one of the obstacles to the introduction of the induction heating cooker.

  There is also an induction heating cooker that can be used with a single-phase 100V AC power supply. For example, there is one that can be used for both single-phase 200V and single-phase 100V. In such an induction heating cooker, in the case of a single-phase 100V, the single-phase 100V is boosted and rectified by a voltage doubler rectifier circuit or a power factor improving step-up rectifier circuit, and the voltage Vdc of the DC part is 200V In either case of single phase 100V, it is set to about 280V. Thereby, the output circuit is shared.

A high AC power source that can be used to heat the food to be cooked, with the AC signal from the commercial AC power supply and the DC signal from the storage battery selected to be larger. There is a power cooker (see, for example, Patent Document 1). That is, a storage battery that supplies a DC voltage that is greater than at least the minimum instantaneous value of the AC voltage supplied from the commercial AC power supply is provided, and in a range where the instantaneous value of the AC voltage is smaller than the DC voltage value from the storage battery, A DC voltage is supplied to the induction heating coil so that sufficient cooking and heating can be performed even with a commercial AC power source.
JP 7-235372 A

  However, the induction heating cooker that can be used for both single-phase 200V and single-phase 100V exhibits the same capability as single-phase 200V because the output circuit is shared. For this reason, when used at a single phase of 100 V, the input voltage is ½, so that twice the input current is required to obtain the conventional maximum output. Therefore, the capacity of the existing indoor wiring appliance for 100V may be exceeded. Therefore, as a countermeasure, the maximum output of the induction heating cooker for single phase 100V is suppressed to be smaller than that for single phase 200V, and it is often impossible to output a desired amount of heat.

  On the other hand, in Patent Document 1, a storage battery is provided, and a DC voltage is supplied from the storage battery to a heater or an induction heating coil. However, when a DC voltage is supplied from the storage battery, an instantaneous value of the AC voltage is a direct current from the storage battery. Since it is only for a range smaller than the voltage value, a desired amount of heat may not be output.

  One of the causes of reducing the willingness to purchase induction heating cookers when viewed from the user is that it is difficult to obtain a desired amount of heat. In addition, when using an induction heating cooker in the home, it is often used in combination with other cooking utensils. In such a case, the load may be temporarily increased, the indoor wiring may be overloaded, and the breaker may be opened.

  An object of the present invention is to provide an induction heating cooker that can prevent overloading of indoor wiring and that can output a desired amount of heat even with a single-phase 100V.

  An induction heating cooker according to the invention of claim 1 includes an induction heating unit driving device that rectifies AC power from a commercial AC power source to obtain DC power, converts the DC power to high frequency power, and supplies the DC power to the induction heating unit; A battery that accumulates power from an AC power source when the power consumption in the induction heating unit is zero or low, and exceeds the battery supply limit power from the battery when the power consumption in the induction heating unit is insufficient with only the AC power source An arithmetic control circuit is provided that controls to supply the shortage to the induction heating unit within a range that is not present, and calculates and displays the operation possible time of the battery.

  An induction heating cooker according to a second aspect of the present invention is the induction heating cooker according to the first aspect of the present invention, wherein the induction heating unit driving device has a rectifier that rectifies AC power from a commercial AC power source, and a power factor of input power of the rectifier. A power factor correction step-down circuit that charges and discharges power to and from the battery according to a DC voltage obtained by stepping down the direct current from the rectifier while improving, and boosts the direct-current power source obtained by the power factor improvement step-down circuit A step-up chopper circuit and a high-frequency power generation circuit that generates a high-frequency power to be supplied to the induction heating unit by controlling the DC power source boosted by the step-up chopper circuit at a high frequency.

  An induction heating cooker according to a third aspect of the present invention is the induction heating cooker according to the first aspect of the present invention, wherein the induction heating unit driving device includes a rectifier that rectifies AC power from a commercial AC power supply, and a power factor of input power of the rectifier. The power factor improving circuit that boosts the direct current from the rectifier while improving, the DC power source obtained by the power factor improving circuit is stepped down to charge the battery, and the battery voltage is stepped up and stored in the battery A step-up / step-down chopper circuit that discharges electric power to the output part of the power factor correction circuit, and a high frequency power generation circuit that generates high frequency power to be supplied to the induction heating part by controlling the direct current power source of the output part of the power factor improvement circuit. It is characterized by comprising.

  According to the present invention, there is provided a battery for accumulating power from an AC power source when the power consumption in the induction heating unit is zero or small, and when the power consumption in the induction heating unit is insufficient with only the AC power source, the battery is switched to the battery. Since the shortage is supplied to the induction heating unit within a range that does not exceed the supply limit power, even a commercial AC power supply can be used even at a temporary high load in the home. In addition, since the battery operable time is calculated and displayed, it can be determined in advance whether a temporary high load occurs in the home.

(First embodiment)
FIG. 1 is a configuration diagram of the induction heating cooker according to the first embodiment of the present invention. The induction heating cooker displays an induction heating unit 11 that generates heat, an induction heating unit driving device 12 that supplies electric power to the induction heating unit 11, a battery 13 that stores electric power, a cooking operation, and various types of information. The operation display unit 14 includes an operation control circuit 15 that controls the induction heating unit driving device 12 based on the operation of the operation display unit 14 and displays various information on the operation display unit 14.

  The induction heating unit 11 is composed of a parallel circuit of a reactor L1 and a capacitor C1, and when a current flows through the reactor L1 of the induction heating unit 11, an eddy current is generated around the reactor, and this eddy current is generated. However, when a metal is brought close to it, a current flows through the metal, and heat is generated by the current and the resistance of the metal to become a heat source for cooking.

  The induction heating unit driving device 12 rectifies AC power from the commercial AC power supply 16 to obtain DC power, converts the DC power into high frequency power, and supplies the DC power to the induction heating unit 11. The AC voltage from the commercial AC power supply 16 is input to the rectifier 17 through the filter capacitor C2, and is converted into DC by the rectifier 17. The DC voltage rectified by the rectifier 17 is input to the power factor correction step-down circuit 18 through the smoothing reactor L2.

  The power factor correction step-down circuit 18 includes a switching element S1, a diode D1, a reactor L3, and a capacitor C3. The switching element S1 is controlled by the drive circuit 19 based on a command from the arithmetic control circuit 15. That is, the arithmetic control circuit 15 has the input current I1 to the power factor correction step-down circuit 18 detected by the current detector CT1, the output voltage V1 of the power factor correction step-down circuit 18 detected by the voltage detector PT1, and the current detector. Based on the battery current Ib detected by CTb, the direct current from the rectifier 17 is stepped down while improving the power factor of the input power of the rectifier 17, and the battery 13 is charged and discharged according to the obtained direct current voltage.

  The DC voltage obtained by the power factor correction step-down circuit 18 is applied to the battery 13 and the capacitor C3. The battery 13 is charged when the DC voltage obtained by the power factor correction step-down circuit 18 is higher than the battery voltage, and discharged when it is lower than the battery voltage. Further, the capacitor C3 charges DC power with the DC voltage obtained by the power factor correction step-down circuit 18. The DC power charged in the battery 13 and the capacitor C3 becomes the DC power source obtained by the power factor correction step-down circuit 18.

  The DC power obtained by the power factor correction step-down circuit 18 is input to the step-up chopper circuit 20. The step-up chopper circuit 20 includes a reactor L 4, a switching element S 2, a diode D 2, and a capacitor C 4, and the switching element S 2 is controlled by the drive circuit 21 based on a command from the arithmetic control circuit 15. That is, the arithmetic control circuit 15 improves the power factor based on the output voltage V1 of the power factor correction step-down circuit 18 detected by the voltage detector PT1 and the output voltage V2 of the boost chopper circuit 20 detected by the voltage detector PT2. The DC power source obtained by the step-down circuit 18 is boosted.

  The DC power source boosted by the boost chopper circuit 20 is input to the high frequency power generation circuit 22. The high-frequency power generation circuit 22 includes a switching element S3, and the switching element S3 is switching-controlled by the drive circuit 23 based on a command from the arithmetic control circuit 15. That is, the arithmetic control circuit 15 performs high frequency control based on the voltage V3 across the induction heating unit 11 detected by the voltage detector PT3, and supplies high frequency power to the induction heating unit 11.

  FIG. 2 is a block configuration diagram of the arithmetic control circuit 15 in the first embodiment. The arithmetic control circuit 15 includes a power factor correction control unit 24 that performs PWM control of the switching element S 1 of the power factor correction step-down circuit 18, a boost control unit 25 that performs PWM control of the switching element S 2 of the boost chopper circuit 20, and a high-frequency power generation circuit 22. There is an IH control means 26 that performs PWM control of the switching element S3, a remaining capacity calculation means 27 that calculates the operation possible time of the battery 13 and displays it on the operation display unit 14, and the battery 13 is fully charged. Whether or not, and the determination result is displayed on the operation display unit 14.

  First, the power factor improvement control means 24 will be described. The battery current Ib detected by the current detector CTb is input to the comparison means 29 and compared with the charging current limit value. The charging current limit value is a current limit value for charging the battery 13, and the difference is input to the subtraction operation means 30. The subtraction calculation means 30 subtracts the difference obtained by the comparison means 29 from the output voltage target value V1r of the power factor correction step-down circuit 18 and outputs it to the difference calculation means 31 as a corrected output voltage target value V1r0. Thereby, when the charging current Ib to the battery 13 exceeds the charging current limit value, the output voltage target value V1r0 becomes small.

  The difference calculation means 31 receives the output voltage V1 of the power factor correction step-down circuit 18 detected by the voltage detector PT1, calculates the difference ΔV1 between the output voltage V1 and the output voltage target value V1r0, and calculates the power factor improvement control means. 24. The power factor correction control means 24 performs PWM control of the switching element S1 via the drive circuit 19 so that the difference ΔV1 between the output voltage V1 and the output voltage target value V1r0 becomes zero. At that time, the switching element S1 is controlled to be on and off so that the input current I1 to the power factor correction step-down circuit 18 detected by the current detector CT1 becomes a sine wave.

  On the other hand, the input current I1 to the power factor correction step-down circuit 18 detected by the current detector CT1 is input to the comparison means 32 and compared with the power supply current limit value. The power supply current limit value is a current limit value when receiving power supply from the commercial AC power supply 16, and the difference is input to the subtraction operation means 30. The subtraction calculation means 30 subtracts the difference obtained by the comparison means 29 from the output voltage target value V1r of the power factor correction step-down circuit 18 and outputs it to the difference calculation means 31 as a corrected output voltage target value V1r0. Thereby, when the input current I1 to the power factor correction step-down circuit 18 exceeds the power supply current limit value, the output voltage target value V1r0 becomes small.

  When the charging current to the battery 13 exceeds the charging current limit value or when the input current I1 to the power factor correction step-down circuit 18 exceeds the power supply current limit value, the output voltage target value V1r0 becomes small. The improvement control means 24 controls the output voltage V1 to decrease. Accordingly, the battery voltage Vb becomes higher, and the charging of the battery 13 is stopped and the discharging from the battery 13 is started.

  On the other hand, when the charging current to the battery 13 is zero or negative (discharge state), or when the input current I1 to the power factor correction step-down circuit 18 is less than the power supply current limit value or zero or small, the output voltage target value V1r0 is Therefore, the power factor correction control means 24 controls the output voltage V1 to increase. Accordingly, the battery voltage Vb becomes lower, the discharge of the battery 13 is stopped, and the charging of the battery 13 is started.

  Next, the boost control means 25 will be described. The output voltage V2 of the boost chopper circuit 20 detected by the voltage detector PT2 is input to the difference calculation means 33, and a difference ΔV2 with respect to the output voltage target value V2r of the boost chopper circuit 20 is calculated. The difference ΔV2 calculated by the difference calculation means 33 is input to the boost control means 25, and the switching element S2 is PWM controlled via the drive circuit 21 so that the difference ΔV2 becomes zero. Thereby, the output voltage V2 of the step-up chopper circuit 20 is controlled to the target value V2r.

  On the other hand, the output voltage V 1 of the power factor correction step-down circuit 18 is input to the comparison means 34 and compared with the discharge end voltage of the battery 13. The end-of-discharge voltage is a discharge limit value that allows the battery 13 to continue discharging. When the output voltage V1 of the power factor correction step-down circuit 18 becomes less than the discharge end voltage, the discharge from the battery 13 cannot be continued, so the operation of the step-up control means 25 is stopped. As described above, the boost control means 25 performs the boost control as long as the output voltage V1 of the power factor correction step-down circuit 18 (the input voltage of the boost chopper circuit) is equal to or higher than the discharge end voltage, and supplies power to the induction heating unit 11 that is a load. Operate to supply.

  Next, the IH control means 26 will be described. The IH control means 26 receives the command signal R from the operation display unit 14 of the induction heating cooker, the voltage V3 across the induction heating unit 11 detected by the voltage detector PT3, and the temperature of the induction heating unit 11 as necessary. Enter T. In FIG. 1, illustration of a temperature detector that detects the temperature T of the induction heating unit 11 is omitted.

  When the command signal R from the operation display unit 14 is input, the IH control means 26 determines the content of the command signal R. For example, it is determined whether the induction heater of the induction heating cooker is on or off, how much heat source is required when the induction heater of the induction heating cooker is turned on, and the like. For example, when the output adjustment knob is adjusted to a position where normal “boiled food” is performed, the heat source requirement is normal, and thus temperature control is not particularly required. In that case, detection of the temperature T of the induction heating unit 11 is omitted. On the other hand, in the case of a heat source request that requires a high temperature such as “fried food”, the temperature T of the induction heating unit 11 is detected from the temperature detector and automatically adjusted to a predetermined temperature. That is, the IH control means 26 performs PWM control of the switching element S3 via the drive circuit 23 so that the heat requested by the command signal R can be output.

  Next, the remaining capacity calculation means 27 and the end of charge determination means 28 will be described. The remaining capacity calculating means 27 is based on the battery current Ib detected by the current detector CTb that changes every moment and the output voltage V1 of the power factor correction step-down circuit 18 detected by the voltage detector PT1. 13 is calculated, and the current discharge amount from the battery 13 is calculated. Then, the operation possible time of the battery 13 when the current discharge is continued is calculated and displayed on the operation display unit 14.

  Further, the end-of-charge determining means 28 determines whether or not the charged amount B of the battery 13 is fully charged, and current detection is performed in a state where the battery voltage Vb is lower than the output voltage V1 of the power factor correction step-down circuit 18. When the battery current Ib detected by the device CTb is smaller than the full charge current limit value, it is determined that the battery is fully charged. The determination result is displayed on the operation display unit 14.

  FIG. 3 is a flowchart showing the operation of the arithmetic control circuit 15 in the first embodiment. First, the arithmetic control circuit 15 determines whether or not the induction heating cooker is in use (the induction heater is on) (S1). When the induction heating cooker is not on, it is determined whether the commercial AC power supply 16 is applied (S2). When the commercial AC power supply 16 is applied, it is determined whether or not the charged amount B of the battery 13 is equal to or less than a predetermined value B0 (S3). As this predetermined value B0, for example, the charged amount in a fully charged state is set. When the charged amount B of the battery 13 is less than or equal to the predetermined value B0, the battery 13 is charged (S4).

  That is, since the input current I1 to the power factor correction step-down circuit 18 is zero when the induction heating cooker is off (not in use), as described above, the output voltage target value input to the difference calculation means 31 V1r0 increases. From this, the power factor correction control means 24 operates in the direction of increasing the output voltage V1, so that the battery voltage Vb becomes lower and the battery 13 is charged.

  On the other hand, if it is determined in step S1 that the switch of the operation display unit 14 is turned on, it is determined whether or not the commercial AC power supply 16 is applied (S5), and the commercial AC power supply 16 is applied. If it is, it is determined whether or not the heat source amount (induction heating unit required output power Pr) requested by the command signal R exceeds the supply limit power Pa0 of the commercial AC power supply 16 (S6). When the induction heating unit required output power Pr does not exceed the supply limit power Pa0 of the commercial AC power supply 16, it is determined whether or not the charged amount B of the battery 13 is equal to or less than a predetermined value B0 (S7). When B is less than or equal to the predetermined value B0, electric power is supplied from the commercial AC power supply 16 to the induction heating unit 11 while charging the battery 13 (S8). When the charged amount B of the battery 13 is not less than or equal to the predetermined value B0, the battery 13 does not need to be charged, so power is supplied from the commercial AC power supply 16 to the induction heating unit 11 (S9).

  Next, when it is determined in step S6 that the induction heating unit required output power Pr exceeds the supply limit power Pa0 of the commercial AC power source 16, power is supplied to the induction heating unit 11 from both the commercial AC power source 16 and the battery 13. Supply (S10). It is determined whether the difference (Pr-Pa0) between the induction heating unit required output power Pr and the supply limit power Pa0 of the commercial AC power supply 16 is smaller than the battery supply limit power Pb0 (S11), and the difference (Pr-Pa0) is determined. When it is smaller than the battery supply limit power Pb0, the storage amount B of the battery 13 and the current induction heating unit output power P are confirmed (S12). Then, based on the charged amount B of the battery 13 and the current induction heating unit output power P, the operation available time H of the battery 13 is calculated (S13), and the calculated operation available time H of the battery 13 is calculated as the operation display unit 14. (S14). When the difference (Pr−Pa0) exceeds the battery supply limit power Pb0 in the determination in step S11, the induction heating unit output power P is set to the sum of the supply limit power Pa0 of the commercial AC power supply 16 and the battery supply limit power Pb0 ( (Pa0 + Pb0) or less (S15), the process proceeds to steps S12 to S14, the operation available time H of the battery 13 is calculated, and the calculated operation available time H of the battery 13 is displayed on the operation display unit 14.

  Moreover, when the commercial alternating current power supply 16 is not applied by determination of step S5, electric power is supplied from the battery 13 to the induction heating part 11 (S16). And it is determined whether the induction heating part request | requirement output electric power Pr requested | required by the command signal R exceeds the supply limit electric power Pb0 of the battery 13 (S17), and when not exceeded, the process of step S12-S14 Then, the operation available time H of the battery 13 is calculated, and the calculated operation available time H of the battery 13 is displayed on the operation display unit 14. If it is determined in step S17 that the induction heating unit required output power Pr requested by the command signal R exceeds the supply limit power Pb0 of the battery 13, the induction heating unit output power P is set to be equal to or less than the battery supply limit power Pb0. The operation is limited (S18), the process proceeds to steps S12 to S14, the operation available time H of the battery 13 is calculated, and the calculated operation available time H of the battery 13 is displayed on the operation display unit 14.

  As described above, in the first embodiment, the power factor correction step-down circuit 18 and the step-up chopper circuit 20 are combined to form two switching elements S1 and S2, and the output of the power factor correction step-down circuit 18 is adjusted. By doing so, the DC power from the battery 13 and the commercial AC power supply 16 can be shared. That is, the DC voltage that can charge the battery 13 is adjusted by the power factor correction step-down circuit 18, and while charging the battery 13, the DC voltage required by the induction heating unit 11 by the boost chopper circuit 20 in the subsequent stage (for example, DC 280 V ) To supply power. When it is necessary to share power supply from the battery 13, the output voltage V 1 of the power factor correction step-down circuit 18 is lowered and electric power is taken out from the battery 13.

  According to the first embodiment, when the power consumption in the induction heating unit 11 is zero or small, the power from the commercial AC power supply 16 is accumulated in the battery 13, and the power consumption in the induction heating unit 11 is only the AC power supply. In the case of shortage, since the shortage is supplied from the battery 13 to the induction heating unit 11 within a range not exceeding the battery supply limit power, even if it is a commercial AC power source or at a temporary high load in the home Can be used. Moreover, since the operation possible time of the battery 13 is calculated and displayed while the battery 13 is in use, the usable load amount can be determined in advance.

(Second Embodiment)
FIG. 4 is a block diagram of an induction heating cooker according to the second embodiment of the present invention. This second embodiment is different from the first embodiment shown in FIG. 1 in that a power factor correction circuit 35 is used instead of the power factor correction step-down circuit 18 and the step-up chopper circuit 20 of the induction heating unit driving device 12. And a step-up / down chopper circuit 36 is provided. The same elements as those in FIG. 1 are denoted by the same reference numerals, and redundant description is omitted.

  The AC voltage from the commercial AC power supply 16 is input to the rectifier 17 via the filter capacitor C2 of the induction heating unit driving device 12, and is converted into DC by the rectifier 17. The DC voltage rectified by the rectifier 17 is input to the power factor correction circuit 35.

  The power factor correction circuit 35 includes a reactor L 4, a switching element S 2, a diode D 2, and a capacitor C 4, and the switching element S 2 is controlled by the drive circuit 21 based on a command from the arithmetic control circuit 15. That is, the arithmetic control circuit 15 uses the input current I1 to the power factor correction circuit 35 detected by the current detector CT1, the input voltage V11 of the power factor improvement circuit 35 detected by the voltage detector PT11, and the voltage detector PT2. Based on the detected output voltage V2 of the power factor correction circuit 35, the direct current from the rectifier 17 is boosted while improving the power factor of the input power of the rectifier 17.

  The step-up / step-down chopper circuit 36 includes a capacitor C3, a reactor L11, a switching element S11, and a switching element S12. The switching element S11 is switching-controlled by a drive circuit 37 based on a command from the arithmetic control circuit 15, and the switching element S12 is controlled to be switched by a drive circuit 38 based on a command from the arithmetic control circuit 15.

  That is, the arithmetic control circuit 15 detects the output current I2 of the power factor correction circuit 35 detected by the current detector CT2, the output voltage V2 of the power factor improvement circuit 35 detected by the voltage detector PT2, and the voltage detector PT12. Based on the voltage V12 across the battery of the step-up / step-down chopper circuit 36, the battery voltage Vb is boosted and the electric power stored in the battery 13 is discharged to the output part (capacitor C4) of the power factor correction circuit 35. The arithmetic control circuit 15 is obtained by the power factor correction circuit 35 based on the output voltage V2 of the power factor improvement circuit 35 detected by the voltage detector PT2 and the battery current Ib detected by the current detector CTb. The DC voltage is stepped down to charge the battery 13.

  The DC voltage boosted by the power factor correction circuit 35 and the DC voltage boosted by the buck-boost chopper circuit 36 are input to the high frequency power generation circuit 22. The high-frequency power generation circuit 22 includes a switching element S3, and the switching element S3 is switching-controlled by the drive circuit 23 based on a command from the arithmetic control circuit 15. That is, the arithmetic control circuit 15 performs high frequency control based on the voltage V3 across the induction heating unit 11 detected by the voltage detector PT3, and supplies high frequency power to the induction heating unit 11.

  FIG. 5 is a block diagram of the arithmetic control circuit 15 in the second embodiment. The arithmetic control circuit 15 includes a power factor correction control means 39 for PWM-controlling the switching element S2 of the power factor improvement circuit 35, a boost control means 40 for PWM-controlling the switching element S11 of the step-up / down chopper circuit 36, and a step-up / step-down chopper circuit 36. Step-down control means 41 for PWM-controlling the switching element S12 and IH control means 26 for PWM-controlling the switching element S3 of the high-frequency power generation circuit 22 are provided. It has a remaining capacity calculating means 27 for displaying, and a charging end determining means 28 for determining whether or not the battery 13 is fully charged and displaying the determination result on the operation display unit 14.

  First, the power factor improvement control means 39 will be described. The output voltage V2 of the power factor correction circuit 35 detected by the voltage detector PT2 is input to the difference calculation means 42, and a difference ΔV2 with the output voltage target value V2r of the power factor improvement circuit 35 is calculated. The difference ΔV2 calculated by the difference calculation means 42 is input to the power factor correction control means 39, and the switching element S2 is PWM controlled via the drive circuit 21 so that the difference ΔV2 becomes zero. At that time, the power factor improvement control means 39 inputs the input current I1 to the power factor improvement circuit 35 detected by the current detector CT1 and the input voltage V11 of the power factor improvement circuit 35 detected by the voltage detector PT11. Then, the switching is performed while the switching element S2 is turned on and off so that the input current I1 to the power factor correction circuit 35 becomes a sine wave.

  Next, the boost control means 40 will be described. The output current I2 of the power factor correction circuit 35 detected by the current detector CT2 is input to the comparison means 43 and compared with the power supply current limit value. The power supply current limit value is a current limit value when power is supplied from the commercial AC power supply 16, and the difference is input to the addition calculation means 44. The addition calculation means 44 subtracts the difference obtained by the comparison means 43 from the output voltage target value V2r of the power factor correction circuit 35, and outputs it to the difference calculation means 45 as a corrected output voltage target value V2r0. As a result, when the output current I2 to the power factor correction circuit 35 exceeds the power supply current limit value, the output voltage target value V2r0 increases.

  The difference calculation means 45 receives the output voltage V2 of the power factor correction circuit 35 detected by the voltage detector PT2, calculates the difference ΔV2 between the output voltage V2 and the output voltage target value V2r0, and outputs it to the boost control means 40. To do. The step-up control means 40 performs PWM control of the switching element S11 via the drive circuit 37 of the step-up / step-down chopper circuit 36 so that the difference ΔV2 between the output voltage V2 and the output voltage target value V2r0 becomes zero. As a result, the battery voltage Vb is boosted, and power is supplied from the battery 13 to the output unit of the power factor correction circuit. As described above, when the output current I2 of the power factor correction circuit 35 exceeds the power supply current limit value, power is supplied from the battery 13 to the output unit of the power factor correction circuit.

  On the other hand, the voltage V12 across the battery of the step-up / step-down chopper circuit 36 is input to the comparison means 46 and compared with the discharge end voltage of the battery 13. The end-of-discharge voltage is a discharge limit value that allows the battery 13 to continue discharging. When the output voltage V1 of the power factor correction circuit 35 becomes less than the discharge end voltage, the discharge from the battery 13 cannot be continued, so the operation of the boost control means 40 is stopped. As described above, the boost control means 40 performs the boost control as long as the voltage V12 across the battery of the step-up / step-down chopper circuit 36 is equal to or higher than the discharge end voltage, and operates to supply power to the induction heating unit 11 that is a load.

  Next, the step-down control means 41 will be described. The command signal R from the operation display unit 14 is input to the determination means 50, and the content of the command signal R determines whether the induction heating cooker is off. Then, when the induction heating cooker is off, the step-down control means 41 is activated to charge the battery 13.

  The battery current Ib detected by the current detector CTb is input to the comparison means 47 and compared with the charging current limit value. The charging current limit value is a current limit value for charging the battery 13, and the difference is input to the subtraction operation means 48. The subtraction calculation means 48 subtracts the difference obtained by the comparison means 47 from the output voltage target value V2r of the power factor correction circuit 35 and outputs it to the difference calculation means 49 as a corrected output voltage target value V2r0. Thereby, when the charging current Ib to the battery 13 exceeds the charging current limit value, the output voltage target value V2r0 becomes small.

  The difference calculation means 49 receives the output voltage V2 of the power factor correction circuit 35 detected by the voltage detector PT2, calculates the difference ΔV2 between the output voltage V2 and the output voltage target value V2r0, and outputs it to the step-down control means 41. To do. The step-down control means 41 performs PWM control of the switching element S12 via the drive circuit 38 so that the difference ΔV2 between the output voltage V2 and the output voltage target value V2r0 becomes zero.

  As a result, the battery 13 is charged by the step-down control means 41, and when the charging current Ib exceeds the charging current limit value, the output voltage target value V2r0 becomes small and the output voltage V2 of the power factor correction circuit 35 decreases. To control. Therefore, the battery voltage Vb increases and the charging of the battery 13 is stopped.

  Next, the IH control means 26 will be described. As in the case of the first embodiment, the IH control means 26 includes a command signal R from the operation display unit 14 of the induction heating cooker, a voltage V3 across the induction heating unit 11 detected by the voltage detector PT3, Furthermore, the temperature T of the induction heating unit 11 is input as necessary. In FIG. 4, a temperature detector that detects the temperature T of the induction heating unit 11 is not shown.

  When the command signal R from the operation display unit 14 is input, the IH control means 26 determines the content of the command signal R. For example, it is determined whether the induction heater of the induction heating cooker is on or off, how much heat source is required when the induction heating cooker is turned on, and the like. In the case of a heat source request that requires a high temperature, the temperature T of the induction heating unit 11 is detected from the temperature detector, and the switching element S3 is PWM controlled via the drive circuit 23 so as to reach a predetermined temperature.

  Next, the remaining capacity calculation means 27 and the end of charge determination means 28 will be described. As in the case of the first embodiment, the remaining capacity calculating means 27 includes the battery current Ib detected by the current detector CTb that changes every moment, and the step-up / step-down chopper circuit 36 detected by the voltage detector PT12. Based on the battery both-ends voltage V12, the current storage amount B of the battery 13 is calculated, and the current discharge amount from the battery 13 is calculated. Then, the operation possible time of the battery 13 when the current discharge is continued is calculated and displayed on the operation display unit 14.

  The end-of-charge determination means 28 determines whether or not the charged amount B of the battery 13 is fully charged. In the state where the battery voltage Vb is lower than the voltage V12 across the battery of the step-up / down chopper circuit 36, current detection is performed. When the battery current Ib detected by the device CTb is smaller than the full charge current limit value, it is determined that the battery is fully charged. The determination result is displayed on the operation display unit 14.

  FIG. 6 is a flowchart showing the operation of the arithmetic control circuit 15 in the second embodiment. Steps S7 and S8 are omitted from the first embodiment shown in FIG. As described above, the step-down control means 41 is activated when the induction heating cooker is off, so that charging is performed when commercial AC power is applied with the induction heating cooker off (S1). To S4), the battery 13 is not charged when the induction cooking device is in use. Further, when the commercial AC power supply 16 is applied with the induction heating cooker turned on and the induction heating unit required output power Pr is smaller than the supply limit power Pa0 of the commercial AC power supply 16, the commercial AC power supply 16 performs induction heating. Since the power consumption of the cooking device can be covered, power is supplied from the commercial AC power supply 16 to the induction heating unit 11 (S5, S6, S9).

  Although the commercial AC power supply 16 is applied with the induction heating cooker turned on, when the induction heating unit required output power Pr is larger than the supply limit power Pa0 of the commercial AC power supply 16, the commercial AC power supply 16 performs induction heating cooking. Since the power consumption of the battery cannot be covered, power is supplied from both the commercial AC power supply 16 and the battery 13 to the induction heating unit 11 within a range that does not exceed the supply limit power Pb0 of the battery 13, and the operation and operation time of the battery 13 is increased. Display (S10 to S14). On the other hand, when the commercial AC power supply 16 is not applied with the induction heating cooker turned off, power is supplied from the battery 13 to the induction heating unit 11 within a range not exceeding the supply limit power Pb0 of the battery 13 (S16 to S16). S18) The operation possible time of the battery 13 is displayed (S12 to S14).

  According to the second embodiment, the step-up / step-down chopper circuit 36 is connected to the output part of the power factor correction circuit 35 (DC power supply part to the induction heating part 11), and the output from the output adjustment knob of the operation display part 14 Since the DC voltage generated by the step-up / step-down chopper circuit 36 is adjusted by the command signal R and the power supplied from the commercial AC power supply 16 is adjusted, the power consumption in the induction heating unit 11 is the same as that of the commercial AC power supply 16 and the step-up / step-down pressure. The battery 13 is shared with the battery 13 via the chopper circuit 36. Therefore, even a commercial AC power supply can be used even during a temporary high load in the home.

  In addition, since the DC power obtained from the commercial AC power supply 16 is charged to the battery 13 from the step-up / step-down chopper circuit 36 when the induction heating cooker is not used, the charged amount of the battery 13 is ensured unless the battery is continuously used for a long time. it can. In addition, when power is supplied from the battery 13, the available operation time of the battery 13 is calculated and displayed, so that a usable load amount can be determined in advance.

The block diagram of the induction heating cooking appliance concerning the 1st Embodiment of this invention. The block block diagram of the arithmetic control circuit in the 1st Embodiment of this invention. 3 is a flowchart showing the operation of the arithmetic control circuit according to the first embodiment of the present invention. The block diagram of the induction heating cooking appliance concerning the 2nd Embodiment of this invention. The block block diagram of the arithmetic control circuit in the 2nd Embodiment of this invention. The flowchart which shows the operation | movement of the arithmetic control circuit in the 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Induction heating part, 12 ... Induction heating part drive device, 13 ... Battery, 14 ... Operation display part, 15 ... Operation control circuit, 16 ... Commercial AC power supply, 17 ... Rectifier, 18 ... Power factor improvement step-down circuit, 19 ... Drive circuit, 20 ... boost chopper circuit, 21 ... drive circuit, 22 ... high frequency power generation circuit, 23 ... drive circuit, 24 ... power factor improvement control means, 25 ... boost control means, 26 ... IH control means, 27 ... remaining capacity Arithmetic means 28 ... end-of-charge determination means 29 ... comparison means 30 ... subtraction calculation means 31 ... difference calculation means 32 ... comparison means 33 ... difference calculation means 34 ... comparison means 35 ... power factor improvement circuit, 36: Buck-boost chopper circuit, 37: Drive circuit, 38: Drive circuit, 39: Power factor improvement control means, 40: Boost control means for PWM control, 41 ... Step-down control means, 42 ... Difference calculation means, 43 ... Comparison means 4 ... addition operation unit, 45 ... differential computing means, 46 ... comparator, 47 ... comparison means, 48 ... subtraction means, 49 ... differential computing means, 50 ... judging means

Claims (3)

  Induction heating unit drive unit that rectifies AC power from commercial AC power source to obtain DC power, converts the DC power to high frequency power and supplies it to induction heating unit, and when power consumption in induction heating unit is zero or low If the AC power supply is insufficient for the battery that stores the power from the AC power source and the AC power source alone, supply the shortage to the induction heating unit within the range that does not exceed the battery supply limit power from the battery. An induction heating cooker comprising: an arithmetic control circuit that controls and displays the operation possible time of the battery.   The induction heating unit driving device includes a rectifier that rectifies AC power from a commercial AC power supply, and a DC voltage obtained by stepping down DC from the rectifier while improving a power factor of input power of the rectifier. A power factor improving step-down circuit for charging and discharging power to a battery; a step-up chopper circuit for stepping up a DC power source obtained by the power factor improving step-down circuit; and a direct-current power source boosted by the step-up chopper circuit for high-frequency control. The induction heating cooker according to claim 1, further comprising a high frequency power generation circuit that generates high frequency power to be supplied to the induction heating unit. The induction heating unit driving device includes a rectifier that rectifies AC power from a commercial AC power source, a power factor improvement circuit that boosts DC from the rectifier while improving a power factor of input power of the rectifier, and the power factor. A step-up / step-down chopper circuit for stepping down a DC power source obtained by an improvement circuit and charging the battery and boosting a battery voltage to discharge the electric power stored in the battery to an output unit of the power factor improvement circuit; The induction heating cooker according to claim 1, further comprising: a high frequency power generation circuit that generates a high frequency power to be supplied to the induction heating unit by performing high frequency control on a direct current power source of an output unit of the power factor correction circuit.

Images