JP2013121306A - Air conditioning apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air conditioning apparatus capable of precisely measuring the power amount.SOLUTION: The air conditioning apparatus includes: a rectification circuit that converts AC power into DC power; an inverter that drives a motor load; a boosting circuit including a chopping element and a boosting rectification circuit; a current sensor that measures the current value of the AD power; current detection means that detects a measurement value of the current sensor; chopping number detection means that counts the number of chopping with respect to a half cycle of the chopping element of the boosting circuit; number-by-number power factor table storing means that selects and outputs a power factor on the basis of the current value from the current detection means and the chopping number; L-value variation detection means that detects a variation of L-value of a reactor from the current detection means; and correction coefficient calculation means that calculates a correction coefficient from the L-value variation detection means. The power amount is calculated using the power factor in which the selected power factor is corrected using the correction coefficient.

Description

  The present invention relates to an air conditioner that can accurately detect the amount of power without adding dedicated components.

  An air conditioner that has an inverter that drives a motor load together with a rectifier circuit that converts AC power to DC power, and when calculating the product of the power supply voltage and the input current by multiplying the power factor, only the input current data Has been devised (see, for example, Patent Document 1).

  FIG. 3 is a block diagram showing a conventional air conditioner. As shown in FIG. 3, the conventional air conditioner is an air conditioner having an inverter 4 that drives a motor 5 together with a rectifier circuit 3 that converts an AC power source 15 into a DC power source. A step-up circuit 2 comprising a chopping element 7 and a step-up rectifier circuit 6, a current sensor 1 for measuring the current value of the AC power source 15, a current detection means 8 for detecting the measured value of the current sensor 1, and a power factor table storage means 20, the voltage value storage unit 12 for outputting a preset voltage value, the voltage value output from the voltage value storage unit 12 and the power factor table value output from the power factor table storage unit 20. A power amount calculating means 11 for calculating the amount is provided.

JP 2003-166748 A

  However, in the conventional configuration, it is possible to measure the electric energy, but since the current waveform varies depending on the number of choppings of the booster circuit, the power factor value varies even if the input load current is the same value. It had the subject that the measurement precision of the electric energy calculated | required by the product of a rate cannot be improved.

  SUMMARY OF THE INVENTION The present invention solves the above-described conventional problems, and an object thereof is to provide an air conditioner that can accurately measure the amount of power regardless of the operating state of a booster circuit.

  In order to solve the above-described conventional problems, an air conditioner of the present invention includes a rectifier circuit that converts an AC power source into a DC power source, an inverter that drives a motor load, a booster circuit that includes a chopping element and a booster rectifier circuit. A current sensor for measuring the current value of the alternating current, a current detection means for detecting the measurement value of the current sensor, a chopping frequency detection means for counting the number of choppings for a half cycle of the chopping element of the booster circuit, and the current Power factor table storage means for selecting and outputting the power factor from the current value from the detection means and the number of choppings, L value variation detection means for detecting L value variation of the reactor from the current detection means, and the L value Correction coefficient calculating means for calculating a correction coefficient from the variation detecting means, and correcting the selected power factor with the correction coefficient. With the added power factor and calculates the amount of power.

Thereby, even when the input load current due to the fluctuation of the current waveform is the same value and the power factor value fluctuates, by storing the power factor table for each predetermined chopping frequency range by the chopping frequency of the booster circuit, An optimal power factor value can be output, and a highly accurate power amount can be calculated. Further, by adding correction due to variations in the L value of the reactor to the power factor table, the amount of power can be calculated with a more optimal power factor value.

  The present invention can provide an air conditioner capable of calculating a highly accurate power amount without mounting expensive power factor measurement components.

The block diagram of the air conditioner in Embodiment 1 of this invention The block diagram of the air conditioner in Embodiment 2 of this invention Block diagram of an air conditioner equipped with a conventional electric energy calculation means

  An air conditioner according to a first aspect of the invention measures a current value of an alternating current, a rectifier circuit that converts an AC power source into a DC power source, an inverter that drives a motor load, a booster circuit that includes a chopping element and a booster rectifier circuit. A current sensor for detecting the measured value of the current sensor, a chopping number detecting means for counting the number of choppings for a half cycle of the chopping element of the booster circuit, the current value from the current detecting means, and the Power factor table storage means for selecting and outputting the power factor from the number of chopping times, L value variation detecting means for detecting L value variation of the reactor from the current detecting means, and a correction coefficient is calculated from the L value variation detecting means. A correction coefficient calculation means for performing power consumption using a power factor obtained by adding the correction by the correction coefficient to the selected power factor By calculating, even when the input load current due to the fluctuation of the current waveform is the same value and the power factor value fluctuates, the power factor table for each chopping frequency range specified in advance is stored by the chopping frequency of the booster circuit Thus, it is possible to output an optimum power factor value and calculate a highly accurate electric energy. Further, by adding correction due to variations in the L value of the reactor to the power factor table, the amount of power can be calculated with a more optimal power factor value.

  In the air conditioner of the second invention, particularly in the first invention, the power factor table storage means for each number of times has a plurality of tables, and selects an optimum table from the plurality of tables according to the number of times of chopping. Thus, a more accurate amount of power can be calculated.

  The air conditioner according to a third aspect of the invention includes the number-of-times corresponding coefficient storage means calculated according to the number of times of chopping, particularly in the first aspect of the invention, and the number-specific power factor table storage means comprises a single standard table. By correcting the power factor by multiplying the power factor calculated by the standard table by the coefficient calculated by the number corresponding coefficient storage means, it is possible to calculate an accurate power factor without having a plurality of tables. As a result, an accurate amount of power can be obtained without increasing the amount of data.

  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 a block diagram of an air conditioner according to Embodiment 1 of the present invention.

As shown in FIG. 1, a rectifier circuit 3 that converts an AC power source 15 into a DC power source, an inverter 4 that drives a motor 5, a booster circuit 2 that includes a chopping element 7 and a booster rectifier circuit 6, and an AC current Current sensor 1 for measuring the value, current detection means 8 for detecting the measurement value of the current sensor 1, chopping frequency detection means 10 for counting the number of choppings for a half cycle of the chopping element 7 of the booster circuit 2, and current detection means A power factor table for each number of times, which selects a power factor table for each number of times from the current value from 8 and the number of choppings from the chopping number detection means 10 and outputs a power factor, and a voltage for outputting a preset voltage value Value storage means 12, L value variation detection means 17 for detecting L value variation of the reactor 19 from the current detection means 8, and the L value A correction coefficient calculation means 18 for calculating a correction coefficient from the variation, and a power amount calculation means 11 for calculating a power amount from the power factor value obtained by correcting the power factor table by the correction coefficient and the voltage value. Yes.

  About the air conditioner comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  First, an air conditioner that requires the inverter 4 that drives the motor 5 boosts the rectified voltage in order to improve performance. For this reason, the chopping element 7 represented by a MOSFET or the like is turned ON / OFF. However, the current waveform changes depending on the number of ON / OFF times, and the power factor also changes at the same load current.

  An accurate power factor value for the load current cannot be calculated only with power factor data in a standard environment at 50 Hz or 60 Hz. For this reason, the power factor table storage means 13 for outputting the optimum power factor value from a predetermined number of chopping times (for example, 1, to 5, to 30, 200 to 1000 times) is used for boosting. The optimum power factor value is output from the number counted by the chopping number detection means 10 for counting the number of chopping operations. As a result, the amount of power can be calculated with an optimum power factor value regardless of the load current.

  Further, the characteristic value fluctuates due to variations in the initial deviation of the reactor 19 and affects the power factor, resulting in variations in the results. In order to correct this variation, the time (di / dt) required to reach a constant current during chopping is measured, and the difference from the di / dt value of the TYP product stored in advance by the L value variation detection means 17 is corrected. By calculating the correction coefficient from the coefficient calculation means 18 and integrating the correction coefficient in the power factor table, the electric energy can be calculated with a more optimal power factor value.

(Embodiment 2)
FIG. 2 shows a block diagram of an air conditioner according to Embodiment 2 of the present invention.

  In FIG. 2, the power factor table storage unit 13 for each number of times includes a standard power factor table storage unit 16 that outputs one standard power factor table, and further calculates a coefficient for each chopping frequency according to the number of chopping operations. A coefficient storage means 14 for each number of times is provided.

  About the air conditioner comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  First, as in the first embodiment, the power factor table for each number of times 13 has a demerit that the ROM data amount is enormous because a plurality of tables are required for each number of chopping operations. Only a simple power factor table is provided.

  Therefore, the coefficient for each chopping frequency stored in advance from the coefficient storage means 14 for each frequency is calculated based on the number of chopping operations. The coefficient for each chopping frequency is, for example, 0.85 when the chopping frequency is 1, 0.88 when the chopping frequency is up to 5, and 0.93 when the chopping frequency is up to 30, and the chopping frequency is 200. It has a coefficient according to the number of chopping, such as 0.95 if it is up to 0.99 and 0.99 if the number of chopping is up to 1000.

Then, the power factor calculated by the standard power factor table storage means can be multiplied by the chopping frequency coefficient calculated by the frequency coefficient storage means 14 to output an optimum power factor value.

  As a result, an optimum power factor value can be calculated regardless of the load current, and an accurate amount of power can be obtained.

  As described above, since the air conditioner according to the present invention can calculate a power amount with low cost and high accuracy, it can be applied to uses such as integration of electricity costs.

DESCRIPTION OF SYMBOLS 1 Current sensor 2 Booster circuit 3 Rectifier circuit 4 Inverter 5 Motor 6 Booster rectifier circuit 7 Chopping element 8 Current detection means 10 Chopping frequency detection means 11 Electric energy calculation means 12 Voltage value storage means 13 Power factor table storage means 14 times Separate coefficient storage means 15 AC power supply 16 Standard power factor table storage means 17 L value variation detection means 18 Correction coefficient calculation means 19 Reactor

Claims (3)

A rectifier circuit that converts an AC power source into a DC power source, an inverter that drives a motor load, a booster circuit that includes a chopping element and a booster rectifier circuit, a current sensor that measures the current value of the AC current, and measurement of the current sensor Current detection means for detecting a value, chopping frequency detection means for counting the number of choppings for a half cycle of the chopping element of the booster circuit, and a power factor is selected and output from the current value from the current detection means and the chopping frequency. Power factor table storage means for each number of times, L value variation detection means for detecting L value variation of the reactor from the current detection means, and correction coefficient calculation means for calculating a correction coefficient from the L value variation detection means, The amount of electric power is calculated using a power factor obtained by adding the correction by the correction coefficient to the power factor. Air-conditioner. The air conditioner according to claim 1, wherein the power factor table storage unit by number of times has a plurality of tables, and selects an optimum table from the plurality of tables according to the number of times of chopping. A coefficient storage unit for each number of times calculated according to the number of times of chopping, and the power factor table storage unit for each number of times has one standard table, and the power factor calculated by the standard table includes the number of times The air conditioner according to claim 1, wherein the power factor is corrected by multiplying by a coefficient calculated by another coefficient storage means.