JP3302277B2 - Inverter device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resonance circuit in which a DC output from a DC power supply circuit via a smoothing capacitor is supplied to a resonance circuit including a resonance coil and a resonance capacitor by controlling on / off of the resonance circuit by switching means. To generate an eddy current in a conductive load placed on the resonance coil portion to heat the load.

[0002]

Conventionally, as an inverter device of this type, an output obtained by converting an AC power supply into a DC power supply is turned on / off by controlling a switching circuit of a resonance circuit composed of a resonance circuit and a capacitor. For example, there is an inverter circuit that is provided as an inverter circuit that resonates and thereby obtains an AC output. For example, a resonance coil is provided as a heating coil, and induction heating is performed using a conductive pot as a load.

In this case, when the output of the inverter circuit is controlled by the on / off control of the switching element, the input current and the regenerative current also fluctuate due to the input voltage and the variation of each product, thereby causing the input power, that is, the heating output, to fluctuate. Since it fluctuates, it is necessary to detect this with a sensor or the like and adjust it so that a predetermined heating output is obtained.

Conventionally, such an adjusting operation is performed so as to adjust the heating output to a predetermined level by operating the device under a predetermined condition at the time of shipment in response to variations in sensors and individual products. And a variable resistor or the like is provided as the adjusting means. As a result, the characteristics of the product to be shipped are made to conform to the standard.

However, as described above, adjusting the level of the input current or the regenerative current by using the variable resistor or adjusting the level of the heating output requires individually adjusting the individual values, and thus the precision is not high. However, there is a problem that the cost is not high because the adjustment work takes a long time. In addition, at the time of heating cooking, from the relationship of controlling the inverter circuit according to the type of pot placed, that is, the material,
At the start of cooking, it is necessary to determine the material of the pot, but at this time, in order to make a determination based on the value of the input current, it is necessary to correct the detected input current, which makes the inverter control complicated. It was to become.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to simplify the adjustment work corresponding to the variation of each product and to improve the accuracy thereof, and to further improve the accuracy of the pot as a load. It is an object of the present invention to provide an inverter device in which a configuration for determining a material such as the above does not become complicated.

[0007]

An inverter device according to the present invention comprises a DC power supply circuit including a rectifier circuit and a smoothing capacitor, a resonance circuit including a resonance coil and a capacitor, a switching element, and a diode connected in anti-parallel thereto. An inverter circuit for converting a DC output of the DC power supply circuit into an AC output; an input voltage detection means for detecting an input voltage of the DC power supply circuit; and an input current detection means for detecting an input current of the DC power supply circuit. Regenerative current detecting means for detecting a regenerative current of the inverter circuit, control means for driving and controlling the switching element so as to perform high-frequency induction heating on the load by the resonance coil, and a state in which a predetermined load is placed. The input voltage detection means, the input current detection means and the regenerative First storage means for storing detection data output from the detection means as unique data, and standard detection data obtained under the same conditions as the heating output when storing the first storage means as standard data. And a second storage unit that performs the second operation on the unique data stored in the first storage unit.
The actual detection data output from the input voltage detection means, the input current detection means, and the regenerative current detection means are corrected by the ratio of the standard data stored in the storage means, and based on the corrected detection data. The present invention is characterized in that the switching element is configured to be controlled by the switching means.

According to the above configuration, when the drive of the inverter circuit is controlled by the input power of the predetermined condition, the device specific to the device obtained from each detection data output from the input voltage detecting means, the input current detecting means and the regenerative current detecting means. When the ratio for performing the correction is obtained from the unique data of the above and the standard data obtained from the average value of the detection data obtained from a plurality of other devices, the drive ratio of the inverter circuit is actually controlled by using the correction ratio. The input data, the input current, and the regenerative current are corrected at the same time, and the input current and the regenerative current for operating with the specified input power are appropriately controlled according to the input voltage at that time. Control can be performed so as to obtain a desired input power.

In the above configuration, it is preferable that the first storage means stores the unique data obtained when the first load is operated with a heating output in a maximum rated state with the reference load placed. (Invention of claim 2).

In this manner, the detection data obtained at the maximum rating is stored as unique data in the storage means. Therefore, in a normal case where the data is used below the maximum rating, the error is smaller than the error at the maximum rating. As a result, the error in practical use can be reduced as much as possible.

The control means controls the input power to be constant when the input voltage by the input voltage detection means is equal to or higher than a rated voltage, and when the input voltage is lower than the rated voltage, the input current is controlled to a predetermined level. (Invention of claim 3).

With the above configuration, the control means controls the inverter circuit so that the input power is constant when the value of the input voltage is equal to or higher than the rated voltage, and when the input voltage is lower than the rated voltage, the value of the input current becomes a predetermined value. Since the inverter circuit is controlled so as not to exceed the level, for example, when the input voltage becomes equal to or higher than the rated voltage due to power supply fluctuation, the input current is controlled so as to reduce the input current to a predetermined input power. When the input voltage becomes low, the inverter circuit can be drive-controlled while preventing the input current from becoming high by preventing the input current, not the input power, from exceeding a predetermined level.

Further, the control means causes the controller to read data corresponding to the input power when the inverter circuit is operated in a state where a power meter is connected to an input path to the DC power supply circuit, and the data is read by a predetermined input power. The inverter circuit may be driven and controlled so that the detected data obtained at that time is stored in the first storage unit as the unique data (the invention of claim 4).

According to the above construction, the unique data stored in the first storage means is automatically detected by the control means so that the input power becomes a predetermined level. Therefore, necessary detection data can be reliably obtained, and correction can be performed based on appropriate data.

The control means is configured to control the drive of the inverter circuit based on the standard data when the unique data stored in the first storage means is not within a predetermined range. (The invention of claim 5).

According to the above configuration, when the inherent data is inappropriate data for some reason, an accurate heating output can be obtained by driving and controlling the inverter circuit using the inherent data as it is. In such a case, the control means drives and controls the inverter circuit using the standard data.
This makes it impossible to perform accurate drive control by correcting the detection data output by each detection means specific to the product.However, although the control of the heating output deteriorates, the operation is stopped. The heating output can be obtained without any.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment in which the present invention is applied to an electromagnetic cooker will be described below with reference to FIGS. FIG. 1 schematically shows an electrical configuration.
The DC power supply circuit 2 constituting the power supply of the inverter circuit 1 includes:
The output of the AC power supply circuit 3 is rectified by a full-wave rectifier circuit 4 as a rectifier circuit, and the rectified output is applied between the DC power supply lines 2a and 2b via a smoothing choke coil 5. The configuration is such that a smoothing capacitor 6 is connected between the lines 2a and 2b.

The AC power supply circuit 3 includes AC power supply lines 3a and 3b for receiving the output of a commercial AC power supply through a power supply plug 7, a power switch 8 and a fuse 9, and a varistor 10 between the power supply lines 3a and 3b. And the noise prevention capacitor 11 is connected.

The inverter circuit 1 is of a single-end type, in which a heating coil 12 as a resonance coil and a collector-emitter of an IGBT 13 as a switching element are connected to DC between DC power lines 2a and 2b, and rectified. The flywheel diode 14 as an element is connected in an anti-parallel state with the IGBT 13, and further, a resonance capacitor 15 is connected in parallel with the heating coil 12. The heating coil 12 is for linking a high-frequency magnetic field to the conductive pot P as a load.

Next, the configuration of the control circuit 16 for controlling the driving of the inverter circuit 1 will be described. The oscillation control circuit 17 controls the IGBT 13 of the inverter circuit 1 by PWM.
On / off control is performed based on a signal, and includes a timing circuit 18, an oscillation circuit 19, an output control circuit 20, and a gate drive circuit 21.

The above-described timing circuit 18 is provided in the IGBT 1
A timing signal for performing an on / off operation while minimizing the switching loss of No. 3 is generated based on the collector voltage of the IGBT 13, and the timing signal is supplied to the oscillation circuit 19 to control the oscillation timing. The oscillating circuit 19 is configured to generate a saw-tooth wave signal Sc serving as a carry signal of the PWM signal.
The output control circuit 20 generates a square wave PW based on a comparison between the above-mentioned sawtooth signal Sc and an output reference level signal Sref from an arithmetic processing circuit 22 as control means described later.
Generate an M signal. The gate drive circuit 21 includes the PWM
The signal is amplified and applied to the gate of the IGBT 13 to perform switching control by a pulse width modulation method.

The input current detection circuit 23 as an input current detection means includes a current transformer 23a interposed in a power supply line 3b in the AC power supply circuit 3, and detects an output based on a secondary output of the current transformer 23a. The entire input current is detected, and an input current detection signal Sin having a voltage level corresponding to the detected current value is supplied to the arithmetic processing circuit 22.

The input voltage detecting circuit 24 as input voltage detecting means includes a series circuit of detecting resistors 24a and 24b connected between the AC power supply line 3a and the DC power supply line 2b. An input voltage to the device is detected based on a voltage signal generated at a common connection point between 24a and 24b, and an input voltage detection signal Sv of a voltage level corresponding to the detected voltage is supplied to the arithmetic processing circuit 22. I have.

A regenerative current detecting circuit 25 as regenerative current detecting means detects a regenerative current based on a secondary output of a current transformer 25a interposed so as to detect a current flowing through the flywheel diode 14, and detects the regenerative current. The configuration is such that a regenerative current detection signal Sk of a voltage level corresponding to the detection voltage is provided to the arithmetic processing circuit 22.

The operation section 26 has a function of issuing an operation start command and an output setting of the inverter circuit 1, and has an output setting signal S of a voltage level corresponding to the output setting.
ps is given to the arithmetic processing circuit 22. The arithmetic processing circuit 22 is constituted by a microcomputer, and has a program stored in advance to control the inverter circuit 1 as described later.

The correction data storage section 27 provided as the first storage means is composed of a non-volatile memory such as an EEPROM, and has an input current detection circuit 23, an input voltage detection circuit 24 and a regenerative current Detection circuit 2
5 is the unique data T
They are stored as I, TV, and TK.

The arithmetic processing circuit 22 has a nonvolatile storage unit therein so as to fulfill the function as the second storage means. This storage unit stores data equivalent to the above-mentioned unique data. The detection data of the average value of the detection data obtained by a plurality of other products is the standard data KI, KV, K
K is stored in advance. In addition, what was acquired corresponding to the typical thing of the pot P of various materials is memorize | stored as standard data.

In the arithmetic processing circuit 22, the input current detection signal Sin from the input current detection circuit 23, the input voltage detection signal Sv from the input voltage detection circuit 24, and the regenerative current detection signal Sk from the regenerative current detection circuit 25 The output level reference signal Sref is generated based on a comparison result with the output setting signal Sps from the operation unit 26, and the output level reference signal Sref is supplied to the output control circuit 20 described above. . At this time, the arithmetic processing circuit 22 compares the value of the result of correcting the value of the detection data by each detection signal based on the unique data and the standard data stored in the correction data storage unit 27 described above. ing.

Next, the unique data TI, TV, and TK stored in the correction data storage unit 27 and a method of detecting them will be described with reference to FIG.
This will be described with reference to FIG. This shows a configuration for acquiring unique data for correcting the detection data corresponding to each product, and in each product, detection data consistent with the standard data may not always be obtained. Therefore, unique data is detected so that correction can be performed for each of the products.

When the AC power supply 28 is connected to the power plug 7 of the product body, a power meter 29 is used to detect the input power.
Intervene. Thus, when the driving of the inverter circuit 1 is controlled, the power input to the AC power supply circuit 3 via the power plug 7 can be detected and the data of the input power can be obtained. The detection data of the wattmeter 29 is connected so as to be input to the arithmetic processing circuit 22. In addition, a pot P, which is a predetermined conductive load, is placed on the heating coil 13.

The arithmetic processing circuit 22 is configured to execute a unique data acquisition program in response to a special operation of a key of the operation unit 26. When this program is started, first, the inverter circuit 1 is set so that a heating output can be obtained under preset rating conditions.
Is controlled. At this time, if the detection data of the input power supplied from the wattmeter 29 does not satisfy the rated condition, the oscillation control circuit 17 continues until the rated condition is reached.
Is controlled so as to change the input current.

When the state becomes stable under the rated condition, the arithmetic processing circuit 22 detects the detection signal Sin input from the input current detection circuit 23, the detection signal Sv input from the input voltage detection circuit 24, and the regenerative current detection. The value of the detection signal Sk input from the circuit 25 is converted into the unique data TI, T
V and TK, and these are stored in the correction data storage unit 2
7 is stored. The data of the unique data TI, TV, and TK stored in this way are read by the arithmetic processing circuit 22 when performing the correction processing as described later.

In the above case, as shown in FIGS. 3 to 5, the values of the detection data of the input current, the input voltage, and the regenerative current are respectively equal to the detection data of the standard product when operated at the rated value. When it is “100”, for example, the product A that is shifted to a larger value of the variation
(Or A ', A "), it is" 100 or more ", or the product B (or B', B"), whose deviation value is shifted to a smaller value, is "100 or less". The detected data value at that time is taken as unique data.

The manner in which the detection data varies in each of the detection circuits 23, 24 and 25 with respect to the standard data can be treated as being approximately proportional (first order approximation). As shown in FIG. 5, by storing the detection data obtained at the point of the rated value as unique data, the error can be reduced for values below the rated value.

Next, as the operation of the present embodiment, the contents of the drive control of the inverter circuit 1 will be described. Prior to this, the correction processing of the detection data necessary for the drive control of the inverter circuit 1 will be described.

That is, the arithmetic processing circuit 22 performs the following processing on the values of the detection data I, V, and K input from the input current detection circuit 23, the input voltage detection circuit 24, and the regenerative current detection circuit 25, respectively. Compensation detection data CI, CV, and CK are obtained by performing the calculation of the appropriate correction processing.

That is, the arithmetic processing circuit 22 first sets the input current KI and the input voltage KV as the standard data described above.
From the value of the regenerative current KK and the values of the input current TI, the input voltage TV, and the regenerative current TK as the unique data, the values of the input current correction ratio HI, the input voltage correction ratio HV, and the regenerative current correction ratio HK are calculated by the following equation ( The calculation is performed according to 1) to (3).

Input current correction ratio HI = KI / TI (1) Input voltage correction ratio HV = KV / TV (2) Regenerative current correction ratio HK = KK / TK (3)

Next, the values HI and H of the respective correction ratios of the calculation result
The input current I, the input voltage V, and the regenerative current K are corrected by performing calculations using the following equations (4) to (6) using the values of V and HK to correct the corrected input current CI and the corrected input voltage CV. And a corrected regenerative current CK.

Input current CI = I × HI (4) Input voltage CV = V × HV (5) Regenerative current CK = K × HK (6)

That is, in the basic calculation of the above-mentioned correction processing, assuming that the standard data is K, the unique data is T, and the correction detection data is C, the detection data is corrected by the general formula shown in the following equation (7). can do. Correction detection data C = [detection data value] × (K / T) (7)

When performing the correction processing as described above,
When the values of the unique data TI, TV, and TK read from the correction data storage unit 27 are out of the predetermined range, the arithmetic processing circuit 22 invalidates the corresponding unique data and replaces the standard data with the invalid data. Even if any abnormality occurs in the storage state of the unique data, the control accuracy is reduced, but the heating operation can be performed without stopping the drive control of the inverter circuit 1. be able to.

Next, the contents of drive control of the inverter circuit 1 will be described. First, while the pot P is placed on the heating coil 12, the power switch 8 is turned on and the operation of the inverter circuit 1 is instructed through the operation unit 26, and the arithmetic processing circuit 22 determines the material of the pot P. A material determination control operation for performing the determination is performed.

Specifically, during the material determination control operation, the inverter circuit 1 outputs a constant output (for example, the material of the pot P placed on the heating coil 12) to the output control circuit 20 in the oscillation control unit 17. Is an output level reference signal Sref of a level necessary to operate at an input power conversion value of 600 W in a state where it is a proper one such as an enamel pan,
It is designed to output only for a short time.

It is to be noted that a suitable material for the pot P is a standard one recommended from the above-mentioned enamel or stainless steel (SUS). If the conductivity is high such as aluminum, the heat generation efficiency is low. It is considered inappropriate because it would be. Therefore, in the material determination control operation, based on the values of the input current and the regenerative current, the determination of the no-load state and the determination of whether or not the pot P is appropriate for performing the heating control operation are performed. In such a case, the material is determined so that the heating operation can be efficiently performed by the subsequent heating control operation.

During the period in which the output level reference signal Sref is output, the IGBT 13 is turned on / off by a PWM signal from the output control circuit 20 receiving the output level reference signal Sref, so that the heating coil 12 of the inverter circuit 1 performs a resonance operation. I will be. At this time, I in the inverter circuit 1
During the ON period of the GBT 13, a current flows from the DC power supply circuit 2 through the heating coil 12 and the IGBT 1
3, a resonance circuit is formed by the heating coil 12 and the resonance capacitor 15. In this state, the charging and discharging of the resonance capacitor 15 is performed through the heating coil 12, and particularly during the discharge, the IGBT is discharged.
When the voltage between the collector and the emitter of the capacitor 13 becomes substantially zero and the discharge from the resonance capacitor 15 stops, a regenerative current flows through the flywheel diode 14 and the heating coil 12 to the smoothing capacitor 6 on the DC power supply circuit 2 side.

At this time, the regenerative current flowing through the flywheel diode 14 is detected as a voltage signal by the current transformer 25a, and is output to the arithmetic processing circuit 22 by the regenerative current detection circuit 25 as a signal Sk indicating the detection data K of the regenerative current. become. When the drive of the inverter circuit 1 is controlled in this way, the AC power supply circuit 3
The current of the AC power supply input from the
Is detected as a voltage signal by the input current detection circuit 23.
As a result, a signal Sin indicating the detection data I of the input current is output to the arithmetic processing circuit 22. Further, the voltage detection circuit 24 outputs the voltage of the AC power supply input to the AC power supply circuit 3 to the arithmetic processing circuit 22 as a voltage signal Sv obtained by dividing the voltage by the detection resistors 24a and 24b.

The arithmetic processing circuit 22 includes detection circuits 23 and 2
, V and K of detection data input from 4, 25
, The material determination process is performed based on the values of the resulting corrected correction input current CI, correction input voltage CV, and correction regeneration current CK. In this case, the values of the input current and the regenerative current have different values depending on the material and the diameter of the pot P, and the material is determined by setting the data corresponding to them as the threshold value in advance. Will be able to

The values of the corrected detection data CI, CV, and CK can be handled as standard values corrected in accordance with the variation of each product, so that the threshold value is set for the judgment. This makes it possible to minimize the occurrence of erroneous determination with respect to the value.

When the material of the pot P is determined as described above, the arithmetic processing circuit 22 subsequently performs control for cooking. That is, for the set heating output, that is, the input power Pin value, the drive control of the inverter circuit 1 is performed under appropriate conditions set in advance corresponding to the pot P of the material. In this case, the arithmetic processing circuit 2
2 performs a correction process in the same manner as described above, and when the input current I, the input voltage V and the regenerative current K are detected, the corrected input current CI, the corrected input voltage CV and the corrected regenerative current CK are corrected. Control is performed based on this.

When the drive control of the inverter circuit 1 is performed as described above, the arithmetic processing circuit 22 controls the heating control according to the value of the input voltage V (corrected input voltage CV) as shown in FIG. The pattern is switched. That is, the input voltage V is equal to the rated voltage (for example, 100
V) or more, that is, if the voltage of the AC power supply is 100 V or more due to some voltage fluctuation, control is performed so that the input current is adjusted so that the power becomes constant according to the voltage fluctuation. (In the figure, the constant power control area). When the input voltage V is lower than the rated voltage, control is performed to adjust the input power so that the input current becomes constant in accordance with the voltage fluctuation (current constant control area in the figure).

For example, if the input voltage V (corrected input voltage CV) is 110 V (volts) when the input power Pin is set to 1000 W (watts), then the input current I (corrected input current CI ) Is 9.0
9A (ampere) (1000W ÷ 110V = 9.09)
And the value of the input power Pin is controlled to be constant. Further, the input voltage V (corrected input voltage C
V) is 90 V, the input current I (corrected input current CI) is kept constant at 10 A, which is the value at the rated 100 V, and the input power Pin (90 V × 10 A =
900W).

As described above, when the input voltage V is lower than the rated voltage, the input power Pin is not controlled to be constant because the input power is kept constant as the input voltage decreases. If the input current is controlled so as to exceed the rating, it is possible to prevent the input current from being set excessively large and imposing a load on the IGBT 13 when the input voltage is instantaneously greatly reduced due to power supply fluctuation.
Can be prevented from flowing an excessive current.

The arithmetic processing circuit 22 calculates the input current I
The following control is performed according to the value of (correction input current CI) and the value of regenerative current K (correction regenerative current CK). That is, first, when driving and controlling the inverter circuit 1, the detected input current I (corrected input current CI) is compared with the data value of the set input current obtained corresponding to the set input power Pin. When the difference between the data values is, for example, “5” or more as the data value, the control amount is controlled to be “5”, and when the difference data value is smaller than “5”, the difference data value is used as it is as the control amount. Control.

By controlling in this manner, vibrations such as overshoot or undershoot occur as compared with the case where the difference between the set input power Pin and the current input power is directly applied as the control amount. It is possible to perform control while relaxing the factor characteristic, and it is possible to perform more appropriate drive control.

In addition to the above control, the arithmetic processing circuit 22 is preset with a value of the input current I (corrected input current CI) and a value of the regenerative current K (corrected regenerative current CK). When it is out of the proper range, the drive control of the inverter circuit 1 is stopped.

In this case, for example, when the rated input voltage is 100
V, the input voltage V (corrected input voltage CV)
Is lower than 80 V or higher than 120 V, the drive control of the inverter circuit 1 is stopped. Further, the input voltage V
Is greater than 130 V, the drive control of the inverter circuit 1 is stopped, and the fact that the input voltage is abnormal is notified.

Further, the arithmetic processing circuit 22 obtains data on the driving control status of the inverter circuit 1 as described above, such as the usage status, the operation time, and the occurrence status of an error, and stores these as correction data as market data. Part 2
7 so that failure analysis can be performed quickly and accurately by reading the market data and viewing the history at the time of repair service, and reflecting the data on product development by accumulating the data. Will be able to do it.

According to the present embodiment, the following effects can be obtained. That is, first, for the respective detection data of the input current detection circuit 23, the input voltage detection circuit 24, and the regenerative current detection circuit 25, the standard data is stored in the arithmetic processing circuit 22 and the correction data storage unit 27 is stored. By storing the unique data due to the variation itself and performing correction processing based on these data, the adjustment work can be performed more quickly than when adjustment work is performed using a variable resistor, etc. The processing can be performed accurately, and the drive of the inverter circuit 1 can be controlled with high accuracy.

Second, the arithmetic processing circuit 22 controls the drive of the inverter circuit 1 by changing the set input power in accordance with the value of the input voltage V (correction input voltage CV), so that the IGBT 13 constituting the inverter circuit 1 It becomes possible to prevent the overcurrent from flowing and being destroyed as much as possible.

Third, the arithmetic processing circuit 22 uses the wattmeter 29 to automatically perform the adjustment work when acquiring the specific data TI, TV, and TK of the input current, the input voltage, and the regenerative current. The adjustment operation can be performed easily and quickly.

Fourth, since the unique data can be rewritten as appropriate, more accurate drive control can be realized in response to fluctuations in accordance with the characteristics of each of the detection circuits 23, 24, and 25. Become.

FIG. 7 shows a second embodiment of the present invention. The difference from the first embodiment is that
In the method of controlling the drive of the inverter circuit 1 according to the above, the value of the input voltage V (corrected input voltage CV) is
V) The setting of the heating output in the following cases is being changed.

That is, when the value of the input voltage V is in the range of 100 V to 95 V, the arithmetic processing circuit 22 controls the input current to be constant in the same manner as in the first embodiment. When the value becomes 95 V or less, control is performed so that the input power is reduced by the square of the variation of the input voltage V. As a result, it is possible to suppress the instantaneous large fluctuation of the current flowing through the IGBT 13 as much as possible and enhance the protection function.

The present invention is not limited to the above embodiment, but can be modified or expanded as follows. The first storage means may be configured to back up a volatile memory such as a RAM with a battery or the like. The second storage means may be configured to also serve as the first storage means.
As the switching element, besides the IGBT 13, an FET, a bipolar transistor, or the like can be used. It can also be applied to electric kettles that perform induction heating. The unique data may be rewritten at any time as needed. Wattmeter 2
When acquiring the unique data by the method 9, the detection point of the detection data may be obtained at an intermediate point other than the maximum rating and adopted as more detailed unique data. The detection data of the wattmeter 29 may be input to the arithmetic processing circuit 22 by an operator.

[0066]

As described above, according to the inverter device of the present invention, the following excellent effects can be obtained. That is, in the inverter device according to the first aspect,
From the device-specific data and the standard data obtained from the average value of the detection data obtained from multiple other devices,
When actually driving and controlling the inverter circuit, the detected data of the input voltage, the input current and the regenerative current are corrected, whereby the input current for operating at the specified input power according to the input voltage at that time is corrected. And the regenerative current can be controlled appropriately to achieve the desired input power, making adjustment work easier and quicker than adjustment work using a variable resistor, etc. It has an excellent effect that it can be performed accurately.

In the inverter device according to the second aspect, in an ordinary case where the inverter device is used below the maximum rating, an error when the device is used at the maximum rating can be reduced, and the error in practical use is minimized. It has an excellent effect that it can be reduced.

In the inverter device according to the third aspect, when the input voltage becomes equal to or higher than the rated voltage due to the power supply fluctuation, the input current is controlled so as to be a predetermined input power, while the input voltage is controlled. When it becomes low, it becomes possible to control the drive of the inverter circuit while preventing the input current from becoming high by preventing the input current from exceeding the predetermined level instead of the input power, and an overcurrent flows in the inverter circuit. This can prevent the switching element from being damaged by overcurrent.

According to the inverter device of the fourth aspect, it is possible to reliably obtain detection data necessary for obtaining unique data, and to perform correction based on appropriate data.

In the inverter device according to the fifth aspect, if the inherent data is inappropriate data for some reason, the drive control of the inverter circuit is performed using the standard data, so that the heating output is controlled with high accuracy. Although it becomes worse, the heating output can be obtained without stopping the operation.

[Brief description of the drawings]

FIG. 1 is a schematic electrical configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a diagram showing a detection configuration for acquiring unique data.

FIG. 3 is a diagram showing a correlation of an input current detection data value with respect to an input current.

FIG. 4 is a diagram illustrating a correlation between an input voltage and an input voltage detection data value.

FIG. 5 is a diagram showing a correlation between a regenerative current detection data value and a regenerative current.

FIG. 6 is a diagram illustrating a control method of input power corresponding to a change in input voltage.

FIG. 7 is a view corresponding to FIG. 6, showing a second embodiment of the present invention.

[Explanation of symbols]

1 is an inverter circuit, 2 is an AC power circuit, 3 is a DC power circuit, 4 is a full-wave rectifier circuit (rectifier circuit), 5 is a smoothing choke coil, 6 is a smoothing capacitor, 12 is a heating coil (resonant coil), 13 Is an IGBT (switching element), 14 is a flywheel diode (rectifying element),
15 is a resonance capacitor, 16 is a control circuit, 17 is an oscillation control circuit, 22 is an arithmetic processing circuit (control means, second storage means), 23 is an input current detection circuit (input current detection means),
23a is a current transformer, 24 is an input voltage detection circuit (input voltage detection means), 24a and 24b are detection resistors, 25 is a regenerative current detection circuit (regeneration current detection means), 25a is a current transformer, and 27 is a correction data storage unit. (First storage means), 28 is an AC power supply, and 29 is a wattmeter.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H05B 6/12 H05B 6/06 H02M 7/48

Claims (5)

(57) [Claims] A DC power supply circuit comprising a rectifier circuit and a smoothing capacitor; a resonance circuit comprising a resonance coil and a capacitor; a switching element; and a diode connected in anti-parallel to the switching element. An inverter circuit for converting to an output; an input voltage detecting means for detecting an input voltage of the DC power supply circuit; an input current detecting means for detecting an input current of the DC power supply circuit; and a regeneration for detecting a regenerative current of the inverter circuit. Current detection means, control means for driving and controlling the switching element so as to perform high-frequency induction heating on the load by the resonance coil, and when operating with a heating output under a predetermined condition with a predetermined load placed. Detection data output from the input voltage detecting means, the input current detecting means, and the regenerative current detecting means are fixed. A first storage unit for storing as stored data; and a second storage unit for storing, as standard data, standard detection data obtained under the same conditions as the heating output when storing in the first storage unit. The control means is configured to determine the input voltage detection means and the input current detection means with a value of a ratio of the standard data stored in the second storage means to the unique data stored in the first storage means. And an inverter device that corrects actual detection data output from the regenerative current detection means and controls the switching element based on the corrected detection data. 2. The apparatus according to claim 1, wherein the first storage means stores the unique data obtained when the apparatus is operated with a heating output in a maximum rated state with the reference load placed. The inverter device according to claim 1. 3. The control means controls the input power to be constant when the input voltage detected by the input voltage detection means is equal to or higher than a rated voltage, and controls the input current to a predetermined level when the input voltage is lower than the rated voltage. The inverter device according to claim 1 or 2, wherein the inverter circuit is configured to drive and control the inverter circuit so as not to exceed the following. 4. The control means reads data corresponding to input power when the inverter circuit is operated in a state where a power meter is connected to an input path to the DC power supply circuit, and the data reads a predetermined input power. 4. The apparatus according to claim 1, wherein said inverter circuit is driven and controlled so that the detected data obtained at that time is stored as said unique data in said first storage means. An inverter device according to any one of the above. 5. The control unit, when the unique data stored in the first storage unit is not within a predetermined range,
The inverter device according to any one of claims 1 to 4, wherein the inverter circuit is configured to drive and control the inverter circuit based on the standard data stored in the second storage means.