JP2014116124A - Induction heating cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an induction heating cooker capable of obtaining a heating power by a commercial power supply and a battery without working a circuit breaker.SOLUTION: In a state that no commercial power supply 9 is input, in the case that heating is performed, a second power supply part 16 stepping up an accumulator battery 13 to supply power to an inverter circuit 6 is operated. In a state that the commercial power supply 9 is input, in the case that heating is performed, a first power supply part 11 stepping up a rectified AC power supply to supply power to the inverter circuit 6 is operated, and a charging circuit 15 is stopped. On the other hand, in the case that the heating is stopped, and a power storage amount of the accumulator battery 13 is less than a predetermined amount, the charging circuit 15 is operated to charge the accumulator battery 13.

Description

  The present invention relates to an induction heating cooker provided with a storage battery.

  Conventionally, this type of induction heating cooker, as shown in FIG. 3, includes a cooking container 101 for heating a cooked food, a top plate 102 for placing the cooking container 101, and an induction magnetic field for heating the cooking container 101. Heating coil 103 to be generated, temperature sensor 104 for detecting the temperature of cooking vessel 101 via top plate 102, inverter circuit 105 for supplying high-frequency current to heating coil 103, and commercial power supply for supplying power from a commercial power source Means 106, rectifier 107 for full-wave rectification of commercial power, power supply unit 108 for supplying full-wave rectified power to inverter circuit 105, power storage unit 109 for storing electrical energy, and commercial power supply to power storage unit The charging circuit 110 for charging 109 and the high-frequency current output from the inverter circuit 105 are controlled, and the cooking vessel 101 is controlled. A control unit 111 that controls the heating power is provided, and the control unit 111 controls the power supply unit 108 to supply the inverter circuit 105 with the power stored in the power storage unit 109 and the power obtained from the commercial power source. Thus, there has been an induction heating cooker that can output high power that cannot be obtained only by a commercial power source.

JP-A-11-111442

  However, in the conventional configuration, it is not clearly shown how to control and optimally supply power from the commercial power source to the power supply unit and charge power supply to the power storage unit. If the supply from the commercial power supply side is excessively large, such as when obtaining a high output exceeding the capacity or charging the storage battery simultaneously with the high output heating, the breaker may fall beyond the supply capacity from the commercial power supply. There is a problem, and a new control method for performing optimal control of supply from a commercial power source and supply to a power storage unit is necessary.

  The present invention solves the above-described conventional problems, and is provided with a constant voltage control circuit for power supply from a commercial power supply, and when the output of the inverter circuit exceeds the supply capacity of the commercial power supply, the constant voltage cannot be maintained. By using constant current control instead of constant voltage control, excessive supply from the commercial power supply side can be prevented. Similarly, the power supply from the power storage unit is also equipped with a constant voltage control circuit, and if the output of the inverter circuit exceeds the supply capacity from the power storage unit, the constant voltage cannot be maintained. When output exceeding the power supply capability is required, it is possible to prevent excessive supply from the power storage unit by performing constant current control instead of constant voltage control. By providing these power control and power storage unit, an object of the present invention is to provide an induction heating cooker that is within the rated power of the commercial power supply even when the output exceeds the supply capacity of the commercial power supply and prevents the breaker from falling. .

In order to solve the above-described conventional problems, a heating cooker according to the present invention includes a main body that constitutes an outer shell, a top plate that is disposed on an upper surface of the main body and on which a cooking container is placed, and is disposed below the top plate. A heating coil that heats the cooking vessel, an inverter circuit that supplies a high-frequency current to the heating coil, a power cord that inputs AC power from a commercial power source, and a first rectifier that rectifies the AC power input from the commercial power source A first power supply unit that boosts the output of the first rectifier, a chargeable / dischargeable storage battery, a second rectifier that converts AC power input from the commercial power source into DC power, and the first A charging circuit that converts the current or voltage of the output of the rectifier 2 to charge the storage battery with power, a second power supply unit that boosts the output of the storage battery, the output of the first power supply unit, and A capacitor that smoothes the output of the second power supply unit and supplies power to the inverter circuit, and the start of each operation of the charging circuit, the first power supply unit, and the second power supply unit, and Control means for controlling the stop, wherein the control means operates the second power supply unit when heating is performed in a state where no AC power is input from the power cord, and the AC power is supplied from the power cord. When heating is performed in a state where power is input, the first power supply unit is operated and the charging circuit is stopped, while heating is stopped and the storage amount of the storage battery is a predetermined amount. In the case of less than, the charging circuit is operated to charge the storage battery.

  As a result, the maximum thermal power can be obtained so that the supply by the commercial power supply does not exceed the rated power regardless of the remaining capacity of the storage battery or the set thermal power of heating, and the storage battery can be charged at an appropriate timing. .

  The induction heating cooker of the present invention can optimally control the power required for charging according to the output request to the inverter drive circuit, and can prevent the supply from the commercial power source from exceeding the rated power.

The whole block diagram of the induction heating cooking appliance in embodiment of this invention The flowchart of the induction heating cooking appliance in embodiment of this invention Overall configuration diagram of a conventional induction heating cooker

1st invention consists of the main body which comprises an outer shell, the top plate which is arrange | positioned on the upper surface of the said main body, and mounts a cooking vessel, the heating coil which is arrange | positioned under the top plate and heats the said cooking vessel, and said heating An inverter circuit for supplying a high frequency current to the coil, a power cord for inputting AC power from a commercial power source, a first rectifier for rectifying the AC power input from the commercial power source, and boosting the output of the first rectifier A first power supply unit, a chargeable / dischargeable storage battery, a second rectifier that converts an AC power source input from the commercial power source into a DC power source, and a current or voltage output from the second rectifier. Charging the storage battery with power, a second power supply unit for boosting the output of the storage battery, smoothing the output of the first power supply unit and the output of the second power supply unit, Above A capacitor for supplying power to the inverter circuit; and a control means for controlling the start and stop of each of the charging circuit, the first power supply section, and the second power supply section, When heating is performed when the AC power is not input from the power cord, the second power supply unit is operated when heating is performed, and when heating is performed while the AC power is input from the power cord Operates the first power supply unit and stops the charging circuit, while stopping the heating and operating the charging circuit when the storage amount of the storage battery is less than a predetermined amount. When the power cord is connected to a commercial power source and there is power supply to the inverter circuit, the storage battery is not charged. Power supplied from the use power directly as the output power of the inverter circuit, falls within always rated power if operated in the output within the rated power the inverter circuit. On the other hand, when there is no output request to the inverter circuit, there is a possibility that only the storage battery is charged. However, if the power required for charging the storage battery is charged within the rated power of the commercial power supply, Always within the rated power. In addition, when the power cord is not connected and there is an output supply to the inverter circuit, the discharge power of the storage battery becomes the output power of the inverter circuit as it is, so it is irrelevant to the rated power of the commercial power source, When there is no output request to the inverter circuit, the inverter circuit is stopped. Therefore, it is possible to prevent the commercial power supply from exceeding the rated power regardless of the operation mode.

  According to a second aspect of the invention, in the induction heating cooker of the first aspect, the control means outputs an output exceeding the rated power of the commercial power source from the inverter circuit in a state where an AC power source is input from the power cord. In the case of outputting, the first power supply unit and the second power supply unit are driven at the same time, so that when the output exceeding the rated power that is the supply capability from the commercial power source is obtained, The first power supply unit operates below the supply capacity from the commercial power source, and the second power supply unit operates below the output capacity of the storage battery to prevent one power supply from being excessively supplied, The induction heating cooking appliance which can be heated by the output exceeding the supply capability from a commercial power source using the electric power stored in the storage battery can be realized.

  A third aspect of the invention is the induction heating cooker according to any one of the first and second aspects, wherein the control means has a rated power of the commercial power source in a state where an AC power source is input from the power cord. When the output from the inverter circuit is less than a predetermined output that is less than the predetermined value, and when the storage amount of the storage battery is less than the predetermined amount, the first power supply unit is operated and the power supplied to the inverter circuit And charging the storage battery by operating the charging circuit at a charging power that does not exceed the rated power of the commercial power supply. When the supply exceeds the rated power and the power supplied from the commercial power source has a margin with respect to the rated power, the storage battery can be charged even during heating, and the remaining capacity of the storage battery is low. What can be obtained even heating power again exceeds the rated power in the middle of the cooking was continued for cooking low firepower.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is an overall configuration diagram of a heating cooker according to the first embodiment of the present invention.

  In FIG. 1, a cooking container 1 is placed on a top plate 2, and the cooking container 1 is heated by an induction magnetic field from a heating coil 3. The temperature sensor 4 detects thermal infrared rays from the cooking container 1, is installed below the heating coil 3, and thermal infrared rays are incident through the visible portion of the top plate 2. The control means 5 is constituted by a microcomputer and controls an inverter circuit 6 that supplies a high-frequency current to the heating coil 3 based on temperature information from the temperature sensor 4. In this embodiment, thermal infrared is detected. However, the present invention is not limited to this as long as temperature information is obtained.

  The user can start and stop heating to switch the power ON / OFF of the heating cooker through the operation / display means 7 or to heat the cooking container 1 installed in the corresponding burner. Moreover, the heating power can be switched when heating, and the temperature control of the deep-fried food can be performed by selecting a menu.

  Further, in response to the user's operation, when the power is turned on, the power LED is turned on, and the current set thermal power can be displayed by the number of LEDs lit according to the adjustment value of the thermal power.

  Further, the control means 5 can make a notification by voice, buzzer or the like via the notification means 8 according to the operation by the user. In addition, the control means 5 can notify the end of cooking via the notification means 8 such as when performing automatic cooking such as rice cooking or boiling, or when heating is stopped after a set time by timer cooking.

  AC power (supplied with AC 100 V in the present embodiment) supplied from the commercial power supply 9 is converted to DC power via the first rectifier 10. The DC power source that has been full-wave rectified by the first rectifier 10 is connected to the first power supply unit 11 and boosted to a predetermined voltage 1 (DC 200 V in the present embodiment).

  Although the first predetermined voltage in the present embodiment is DC 200 V, it is set in consideration of the power semiconductor that is a component of the inverter circuit 6 and the conversion efficiency, and is not limited to this.

  The output boosted by the first power supply unit 11 is supplied to the capacitor 12 and smoothed. In the present embodiment, the booster circuit has an AC 100V input, an input current MAX of 14A, an output voltage of 200V, and an output current MAX of 7A. The first power supply unit 11 is a circuit having a PFC function for improving the power factor and having input current detection means for monitoring the input current.

  The storage battery 13 uses a lithium ion battery as a battery cell, and is a storage battery 13 with a rated voltage of 50 V and 1000 Wh. In this embodiment, the lithium ion battery is used. However, other storage batteries such as a nickel cadmium storage battery, a nickel hydride storage battery, and a lead storage battery can be used as long as the charge / discharge time, size, and price are balanced. Good.

  The storage battery 13 is charged via a charging circuit 15 that converts the AC power supplied from the commercial power supply 9 into a charging voltage from the power converted into the DC power via the second rectifier 14.

  The charging circuit 15 is a constant voltage constant current circuit that steps down AC 100 V and converts it to a DC voltage of 50 V. The charging circuit 15 performs constant current charging while the charging voltage of the storage battery 13 is low, and constant voltage charging when the charging voltage increases. The CVCC method is used. In the present embodiment, the charging circuit 15 is a CVCC method, but may be a pulse charging method as long as the life of the storage battery 13 and the environmental temperature are balanced.

  The second power supply unit 16 that boosts the output power of the charged storage battery 13 is a chopper type booster circuit that boosts DC50V to DC200V, and includes input current detection means that monitors the output voltage and monitors the input current, The ON time of the switching element of the booster circuit is controlled.

  The first power supply unit 11 uses a preset first predetermined current value (in this embodiment, a value DC14A obtained by excluding current used in other circuits from the commercial power supply capability) and an input current. In comparison, when the input current is less than DC14A, the voltage of the capacitor 12 is boosted to be 200V. When the input current is DC14A or more, the input current is DC14A, not the control by the voltage feedback of the capacitor 12. Boost control is performed as follows.

  The first power supply unit 11 is connected to the control unit 5 and starts and stops the boosting operation according to a signal from the control unit 5.

  The second power supply unit 16 compares a second predetermined current value set in advance (DC20A as the allowable discharge current of the storage battery 13 in this embodiment) with the input current, and during the period less than DC20A Boost control is performed so that the voltage of the capacitor 12 becomes 200 V. When the voltage becomes DC 20 A or more, boost control is performed so that the input current becomes DC 20 A, not the control based on the voltage feedback of the capacitor 12.

  The second power supply unit 16 is connected to the control means 5 (which is a microcomputer in this embodiment), and starts and stops the boosting operation according to a signal from the control means 5.

  The charging circuit 15 is controlled and stopped by the control means 5 and the output current is controlled. The control means 5 stops the charging operation of the charging circuit 15 when the inverter circuit 6 is in the heating operation. The current supplied from the commercial power supply 9 is prevented from exceeding the first predetermined current value.

  However, when the inverter circuit 6 is in a heating operation, the control means 5 determines that the difference between the input current of the first power supply unit 11 and the first predetermined current value is the third predetermined current value (in this embodiment, the storage battery Charging circuit 15 so that the sum of the input current of first power supply unit 11 and the input current of charging circuit 15 does not exceed the first predetermined current value. Of the storage battery 13 by the charging circuit 15 as long as the supply current from the commercial power supply 9 does not exceed the first predetermined current value even when the heating operation of the inverter circuit 6 and the charging of the storage battery 13 are performed simultaneously. Try to charge.

  Next, operation | movement of the control means 5 is demonstrated using FIG. FIG. 2 is a flowchart of the induction heating cooker in the present embodiment.

  First, when the power cord is not connected to the commercial power source in S2, the charging circuit 15 is stopped in S3, and in S4, the user operates the operation / display means 7 to perform the heating start operation of the induction heating cooker. If so, the control means 5 determines that heating is in progress. In this case, only the second power supply unit is driven in S6, the inverter circuit 6 is driven in S7, and the set thermal power is output. In the present embodiment, the storage battery 13 has a capacity of 1000 Wh, and the output power MAX from the storage battery 13 is 1000 W. Therefore, when not connected to a commercial power source, the maximum set thermal power is limited to 1.0 kW, and the output may decrease depending on the state of charge of the storage battery 13. In addition, although the storage battery 13 in this Embodiment was 1000 Wh and the maximum output electric power was 1000 W, it is not restricted to this by the balance of the magnitude | size of a storage battery 13, and a price. Moreover, when a user does not perform heating start operation of an induction heating cooking appliance in S4, an induction heating cooking appliance will be in a halt condition.

  Further, when the power cord is connected to the commercial power source in S2, if the user operates the operation / display means 7 in S9 and performs the heating start operation of the induction heating cooker, the control means 5 to decide. In this case, only the first power supply unit is driven in S17. Next, in S18, it is determined whether or not the set thermal power is equal to or greater than a predetermined output (in this embodiment, the predetermined output is 1.4 kW). The predetermined output is set to a value obtained by subtracting the power consumption of other circuits from the power calculated from the supply capacity of the commercial power supply. If the set thermal power is greater than or equal to the predetermined output in S18, the charging circuit 15 is stopped in S19, and it is checked in S20 whether power can be supplied from the storage battery 13. First, the state of charge of the storage battery 13 is confirmed. If it is not in a dischargeable state to the extent that power can be supplied, the second power supply unit 16 is stopped in S21, and only the first power supply unit 11 is driven. The inverter circuit 6 is driven to output a predetermined output (1.4 kW). If it is determined in S20 that discharging is possible, the first power supply unit 11 and the second power supply unit 16 are driven in S24, the inverter circuit 6 is driven in S25, and the set thermal power is output. In this embodiment, the maximum set thermal power is 2.4 kW, and the set thermal power that can be set by the user with the operation / display means 7 is 2.4 kW.

  If the set thermal power is less than the predetermined output in S18, the control means 5 drives only the first power supply unit 11. Therefore, the second power supply unit 16 is stopped in S27, and the inverter circuit 6 is driven in S28. And output the set thermal power. The control means 5 confirms the state of charge of the storage battery 13 in S29, and if it is not fully charged, the charging circuit 15 starts constant current charging of the storage battery 13 with the current obtained by subtracting the set output from the predetermined output in S30.

If heating is not performed in S9, the inverter circuit 6 is stopped in S10, and the first power supply unit 11 and the second power supply unit 16 are stopped in S11. In S12, the state of charge of the storage battery 13 is confirmed. If the battery is not fully charged, the charging circuit 15 is driven in S13 to start charging. If the storage battery 13 has been charged in S12, the charging circuit 15 is stopped in S15.

  In the present embodiment, the first power supply unit 11 is provided for power supply from the commercial power source, and when the output of the inverter circuit 6 is less than the commercial power supply capability, constant voltage control is performed to exceed the supply capability. In this case, since the constant voltage cannot be maintained, when the first power supply unit 11 needs to output more than the power supply capability of the commercial power supply, the constant power control is used instead of the constant voltage control. An excessive supply from the side can be prevented.

  Similarly, the power supply from the storage battery 13 is provided with a second constant power control circuit, the output of the inverter circuit 6 is 1.4 kW or more, which is the supply of commercial power, and the required power is 2.4 kW. In this case, the second power supply unit 16 uses constant current control so that the output from the storage battery 13 does not exceed the power supply capacity so that the supply capacity from the storage battery 13 does not exceed 1 kW. Can be prevented.

  Further, the output of the inverter circuit 6 is less than 1.4 kW, which is the supply amount of commercial power, and the state of charge of the storage battery 13 is confirmed. Thus, by making constant current control the input current to the storage battery 13, it becomes within the rated power of a commercial power supply, and it can prevent that a breaker falls.

  For example, when the required power to the inverter is 1.0 kW, a current of 10 A from the commercial power supply becomes an output of 1.0 kW in the inverter circuit 6. At this time, if the storage battery is charged at the same time, a maximum current of 10 A may flow to the charging circuit (in this embodiment, the storage battery with the rated voltage of 50 V and 1000 Wh is used, so the maximum input current at the commercial power supply AC 100 V is 10 A. ), A current of 20A flows from the commercial power supply, resulting in an excessive supply of the commercial power supply, and when the breaker falls, or depending on the device, the operation is stopped by a security mechanism (overcurrent detection, etc.). By providing the first power supply unit 11 and the second power supply unit 16 in the form of the above, charging is performed within the supply capacity of the commercial power supply, so that a current within 4 A flows through the charging circuit and the breaker falls. An induction cooker can be provided that prevents it.

  As described above, the induction heating cooker according to the present invention can output together with the power stored in the storage battery with the power exceeding the supply capacity of the commercial power supply, and thus can be similarly applied to other cookers. can do.

DESCRIPTION OF SYMBOLS 1 Cooking container 2 Top plate 3 Heating coil 5 Control means 6 Inverter circuit 10 1st rectifier 11 1st electric power supply part 12 Capacitor 13 Storage battery 14 2nd rectifier 15 Charging circuit 16 2nd electric power supply part

Claims (3)

A main body constituting the outer shell, a top plate disposed on the upper surface of the main body for placing the cooking container, a heating coil disposed below the top plate for heating the cooking container, and a high-frequency current supplied to the heating coil An inverter circuit, a power cord for inputting AC power from the commercial power source, a first rectifier for rectifying the AC power input from the commercial power source, and a first power supply unit for boosting the output of the first rectifier And a chargeable / dischargeable storage battery, a second rectifier that converts an AC power input from the commercial power supply into a DC power supply, and an electric current or voltage at the output of the second rectifier to convert the power to the storage battery. A charging circuit for charging; a second power supply unit for boosting an output of the storage battery; and an output of the first power supply unit and an output of the second power supply unit are smoothed, and the inverter circuit A capacitor for supplying power; and a control means for controlling start and stop of each of the charging circuit, the first power supply section, and the second power supply section, and the control means includes the power cord When heating is performed in a state where no AC power is input from the second power supply unit, the second power supply unit is operated, and when heating is performed in a state where AC power is input from the power cord, the second power supply unit is operated. 1 is operated and the charging circuit is stopped. On the other hand, when heating is stopped and the storage amount of the storage battery is less than a predetermined amount, the charging circuit is operated to charge the storage battery. Perform induction heating cooker. The control means is configured to output the first power supply unit and the second power supply when the inverter circuit outputs an output exceeding the rated power of the commercial power supply in a state where an AC power supply is input from the power cord. The induction heating cooker according to claim 1, wherein the power supply unit is driven simultaneously. The control means outputs, from the inverter circuit, an output equal to or less than a predetermined output that is less than the rated power of the commercial power supply in a state in which an AC power supply is input from the power cord, and a storage amount of the storage battery is predetermined. If the amount is less than a fixed amount, the first power supply unit is operated, and charging is performed such that the power combined with the power supplied to the inverter circuit and the power supplied to the charging circuit does not exceed the rated power of the commercial power supply The induction heating cooker according to claim 1 or 2, wherein the charging circuit is charged by operating the charging circuit with electric power.

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