JPH06147661A - Air conditioner - Google Patents

Abstract

PURPOSE:To provide an air conditioner having an invertor therein for compensating a primary resistance varied in response to temperature, preventing the controlling accuracy from being lowered by a variation in the primary resistance and attaining a high efficiency. CONSTITUTION:An air conditioner comprises a shell discharging pressure sensor 33 for sensing the discharge pressure of a compressor 1, a refrigerant flow rate sensor 34 for sensing the refrigerant flow rate within a discharging pipe, a shell discharging temperature and motor temperature estimating circuit 32 for estimating the shell discharging temperature and the motor temperature in reference to the discharging pressure and the refrigerant flow rate, a primary resistance estimating circuit 31 for estimating the primary resistance set value RLAMBDAs in reference to the motor temperature and a vector control instruction calculation circuit 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner provided with a control device for controlling an inverter by vector control of a compressor.

[0002]

2. Description of the Related Art In recent years, an air conditioner has been used which controls the capacity by increasing or decreasing the number of revolutions of a compressor by using an inverter device which makes a frequency of a power source variable.

Further, as an inverter control system for a general-purpose inverter, excellent response and power saving can be obtained, so that vector control is often adopted. Therefore, in recent years, the vector control has been applied to the variable speed control system of the compressor of the air conditioner.

This vector control method includes a magnetic flux detection type vector control method in which a secondary magnetic flux is detected as a vector quantity and used as a control signal of a primary current, and a slip frequency type vector in which a magnetic flux vector is calculated and controlled based on a motor constant. A control method is known.

As a technique relating to a conventional slip frequency type vector control system, for example, Japanese Patent Laid-Open No. 64-04309.
There is one disclosed in Japanese Patent Publication No. 7.

An example of the operation of the prior art will be described below with reference to the drawings with reference to FIGS.

FIG. 15 is a block diagram of a conventional air conditioner. FIG. 16 is a block diagram of a slip frequency type vector control device which is an inverter device of a conventional air conditioner.

In FIG. 15, 1 is a compressor, 2 is a four-way valve, 3 is an indoor heat exchanger, 4 is a pressure reducing device, and 5 is an outdoor heat exchanger, and these are connected in a ring to form a refrigeration circuit. ing.

Reference numeral 6 is an indoor fan, and 7 is an outdoor fan.
Reference numeral 8 is an inverter control device that controls the rotation speed of the compressor 1, and 9 is a three-phase AC power supply. That is, 10 is an indoor unit, and 11 is an outdoor unit.

A conventional slip frequency type vector control inverter device is shown in FIG. 16 and will be described with reference to FIG.

In the figure, 1 is a compressor, 13 is a three-phase power amplifier, 14 is a primary voltage command value vdes * seen on an orthogonal coordinate axis (de-qe axis) rotating at a primary angular frequency ω,
vqes * (subscripts des * and qes * are de axes,
A coordinate converter for converting (representing the primary component on the qe axis) into a three-phase alternating current. The three-phase power amplifier 13 and the coordinate converter 1
Reference numeral 4 constitutes a power supply device.

15 is a three-phase alternating current iu which is a primary current,
A coordinate converter that converts iv and iw into an excitation component current ides and a torque component current iqes, which are primary currents on the de-qe axis, and 16 is a three-phase AC voltage vu, vv, v that is a primary voltage.
A coordinate converter that converts w into primary voltages vdes and vqes on the de-qe axis, and 17 is a secondary flux linkage equivalent amount λ'de
r, λ `qer (subscripts der and qer are de axes,
It is an equivalent quantity computing unit that computes (representing a secondary component on the qe axis).

Reference numeral 18 is an estimated value λ ^ der of the secondary interlinkage magnetic flux and an estimated value p of the slip angular frequency p under vector control.
^ Ωs is the output of the coordinate converter 15, ie, ids, iqe
A magnetic flux / slip angular frequency estimator calculated from s and the secondary resistance constant R ^ r, and 19 is an estimated value λ of the secondary flux linkage equivalent amount.
An estimated value calculator that calculates ^ `der, λ ^` qer from λ ^ der which is the output of the magnetic flux / slip angular frequency estimator 18 and the primary angular frequency ω, and 20 is the rotational angular velocity of the induction motor inside the compressor 1. The estimated value p ^ ωr is calculated by using the outputs of the corresponding amount calculator 17, λ "der and λ" qer, and the secondary resistance constant R.
^ R and the output of the estimated value calculator 19, λ ^ qer,
This is a rotational angular velocity estimator that calculates from λ ^ der and p ^ ωs which is the output of the magnetic flux / slip angular frequency estimator.

Reference numeral 23 is an adder for adding p ^ ωr which is the output of the rotational angular velocity estimator 20 and p ^ ωs which is the output of the magnetic flux / slip angular frequency estimator to obtain the primary angular frequency ω, and 21 is the primary angle An integrator that integrates the frequency ω and obtains the phase θ, 22 is the output of θ of the integrator 21, and the coordinate converter 1
6 is a trigonometric function generator for finding sin θ and cos θ input to 6.

Numeral 24 is a subtracter for subtracting the output is output from the coordinate converter 15 from the excitation current command value ides *.
Reference numeral 5 denotes a subtracter that subtracts iques, which is the output of the coordinate converter 15, from the torque current command value iqes *.

Reference numerals 26 and 27 denote primary voltage command values vd input from the outputs of the subtracters 24 and 25 to the coordinate converter 14, respectively.
It is a PI compensator that outputs es * and vqes *.

The equivalent amount calculator 17 has primary voltages vdes, v
By inputting qes, primary currents ides, iqes, primary resistance setting value R ^ s and primary angular frequency ω, the secondary flux linkage equivalents λ'der, λ'qer are calculated based on (Equation 1).

[0018]

[Equation 1]

Here, R ^ s, Ls, Lr, M, and σ are the primary resistance setting value of the induction motor inside the compressor 1, the primary inductance, the secondary inductance, the mutual inductance, the leakage coefficient, and P is the differential operator, T is a first-order lag time constant.

The magnetic flux / slip angular frequency estimator 18 inputs the primary currents ides, iqes and the secondary resistance set value R ^ r (Equation 2), and the secondary chain in the vector controlled state based on (Equation 3). An estimated value λ ^ der of the cross magnetic flux and an estimated value p ^ ωs of the slip angular frequency are calculated.

[0021]

[Equation 2]

[0022]

[Equation 3]

Here, R ^ r is a secondary resistance setting value of the induction motor inside the compressor 1. The estimated value calculator 19 inputs the estimated value λ ^ der of the secondary flux linkage and the primary angular frequency ω,
Based on (Equation 4), the estimated value of the secondary flux linkage equivalent λ ^ `d
er and λ ^ `qer are calculated.

[0024]

[Equation 4]

The rotational angular velocity estimator 20 calculates the equivalent values of the secondary interlinkage magnetic fluxes λ`der, λ`qer and the estimated values of the secondary interlinkage magnetic flux equivalents λ ^ `der, λ ^` qer and the slip angular frequency. By inputting p ^ ωs, the estimated value p ^ ωr of the rotational angular velocity of the induction motor inside the compressor 1 is calculated based on (Equation 5).

[0026]

[Equation 5]

However, K is a positive constant. The adder 23 adds the estimated value p ^ ωr of the rotational angular velocity and the estimated value p ^ ωs of the slip angular frequency and outputs the primary angular frequency ω. The integrator 21 integrates the primary angular frequency ω and outputs a phase signal θ. The trigonometric function generator 22 inputs the phase signal θ and outputs the corresponding sine and cosine.

The subtractor 24 and the PI compensator 26 perform feedback control so that the excitation current ides follows the excitation current command value ides *. The subtractor 25 and the PI compensator 27 perform feedback control so that the torque component current iqes follows the command value iqes * of the torque component current.

[0029]

Since the conventional slip frequency vector controller is constructed as described above,
In an actual induction motor inside a compressor, its primary resistance value Rs varies from 0 ° C. to 1 depending on conditions such as load conditions and ambient temperature.
Since it changes up to about 20 ° C., for example, when the resistance value at 60 ° C. is used as a reference, it fluctuates up and down by about 20%.
Equivalent amount of secondary interlinkage magnetic flux represented by (Equation 1) λ `der, λ
In the steady state, the equation of “qer” becomes (Equation 6) when the differential term is omitted.

[0030]

[Equation 6]

Further, the estimated value p ^ ωs of the slip angular frequency in the steady state becomes (Equation 7) from (Equation 2) and (Equation 3) when the differential term is ignored.

[0032]

[Equation 7]

Since the equation (6) includes the primary resistance setting value R ^ s, there is a temperature variation between the primary resistance setting value R ^ s and the actual primary resistance value Rs of the induction motor in the compressor 1. If an error occurs, the amount of secondary flux linkage λ der, λ
The calculation accuracy of "qer" deteriorates. Further, in (Equation 6), | ωσLs | is the primary resistance setting value R ^ in the low speed region.
Since it is sufficiently smaller than s, the influence of the error of the primary resistance value Rs on the calculation of the secondary interlinkage magnetic flux equivalents λ'der, λ'qer becomes larger. Therefore, the rotational angular velocity estimator 20 represented by (Equation 5) is equivalent to the secondary interlinkage magnetic flux amount λ′der,
Since λ`qer is included, there is a problem to be solved such that an estimation error occurs in the estimated value p ^ ωr of the rotational angular velocity due to the temperature variation of the primary resistance value Rs, which is large especially in the low speed region and the control becomes unstable. .

In view of the above problems, the present invention provides an air conditioner for slip frequency vector control, which corrects the temperature change of the primary resistance of the induction motor inside the compressor and compensates for the deterioration of the vector control characteristic due to the temperature change. The purpose is to do.

[0035]

To achieve this object, an air conditioner of the present invention comprises a compressor whose rotation speed is controlled by a power converter, and a current detector which detects the primary current of the compressor. , Estimating the shell discharge temperature and the motor temperature from the output signal of the shell discharge pressure detector that detects the discharge pressure of the compressor and the output signal of the refrigerant flow rate detector that detects the refrigerant flow rate in the shell discharge pipe of the compressor A shell discharge temperature / motor temperature estimation circuit, a primary resistance estimation circuit that estimates the primary resistance of the motor from the output signals of the shell discharge temperature / motor temperature estimation circuit, and the three-phase power amplifier from the output signal of the primary resistance estimation circuit. It is configured by a vector control command calculation circuit to be driven, and the primary resistance of the motor, which is a calculation element of the vector control command, is output by the output signal of the primary resistance estimation circuit. It corrects the variation with temperature of, is to compensate for the decrease in vector control characteristics due to a temperature change.

The output signal of the shell discharge pressure detector for detecting the shell discharge pressure of the compressor, the output signal of the shell suction pressure detector for detecting the shell suction pressure of the compressor, and the shell suction temperature of the compressor. From the output signal of the shell suction temperature detector for detecting the discharge end temperature and motor temperature estimating circuit for estimating the discharge end temperature and motor temperature inside the compressor, and the output signal of the discharge end temperature and motor temperature estimating circuit A vector control command is configured by a primary resistance estimation circuit that estimates the primary resistance of the motor inside the compressor, and a vector control command calculation circuit that drives the three-phase power amplifier from the output signal of the primary resistance estimation circuit. A primary resistance estimation circuit that compensates for changes in the primary resistance of the motor due to temperature, which is an element of the above calculation, is provided.

Further, the output signal of the shell discharge pressure detector for detecting the shell discharge pressure of the compressor, the output signal of the shell suction pressure detector for detecting the shell suction pressure of the compressor, and the shell suction of the compressor. Estimating the discharge end temperature inside the compressor from the output signal of the shell suction temperature detector that detects the temperature, and estimating the motor temperature inside the compressor from the discharge end temperature and the output signal of the shell discharge temperature detector From the output signal of the discharge end temperature / motor temperature estimation circuit and the output signal of the discharge end temperature / motor temperature estimation circuit, which estimates the primary resistance of the motor inside the compressor from the output signal of the primary resistance estimation circuit It is configured by a vector control command calculation circuit for driving the three-phase power amplifier, and the temperature of the primary resistance of the motor, which is an element of the calculation of the vector control command, is controlled. And a primary resistance estimating circuit to compensate for changes caused by.

[0038]

With the above-described structure, the present invention can realize the efficient air conditioner by compensating the primary resistance Rs which changes with temperature and preventing the control accuracy from being lowered by the change of the primary resistance.

[0039]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An air conditioner according to an embodiment of the present invention will be described below with reference to the drawings. The same components as those of the conventional example are designated by the same reference numerals and the description thereof will be omitted.

1, FIG. 2, FIG. 3, FIG. 4, FIG.
1 shows a first embodiment of the present invention. In FIG. 1, 33 is a shell discharge pressure detector that detects the shell discharge pressure of the compressor 1, 34 is a refrigerant flow rate detector that detects the refrigerant flow rate in the shell discharge pipe of the compressor 1, and this shell discharge pressure detection The vessel 33 and the refrigerant flow rate detector 34 are connected to the shell discharge temperature / motor temperature estimation circuit 32 of FIG. 2, and the shell discharge temperature / motor temperature estimation circuit 32 is connected to the primary resistance estimation circuit 31.

Equivalent amount λ of the secondary interlinkage magnetic flux represented by (Equation 1)
In the steady state, the equations for "der and λ" qer become (Equation 6) when the differential term is omitted.

Since the equation (6) includes the primary resistance setting value R ^ s, an error occurs between the primary resistance value R ^ s and the actual primary resistance value Rs of the induction motor inside the compressor 1 due to temperature fluctuation. Occurs, the secondary flux linkage equivalents λ "der, λ" q
The calculation accuracy of er deteriorates. Further, in (Equation 6), | ωσLs | is the primary resistance setting value R ^ s in the low speed region.
Since it is sufficiently smaller than the above, the influence of the error of the primary resistance value Rs on the calculation of the secondary interlinkage magnetic flux equivalent amounts λ′der and λ′qer becomes larger. Therefore, the rotational angular velocity estimator 20 represented by (Equation 5) uses the secondary flux linkage magnetic flux equivalent amount λ'de
Since r and λ`qer are included, an estimation error occurs in the estimated value p ^ ωr of the rotational angular velocity due to the temperature fluctuation of the primary resistance value Rs, which is large particularly in the low speed region, which makes control unstable and vector control characteristics deteriorate. To do.

In this embodiment, a shell discharge pressure detector 33 for detecting the shell discharge pressure of the compressor 1, a refrigerant flow rate detector 34 for detecting the refrigerant flow rate in the shell discharge pipe of the compressor 1,
A shell discharge temperature / motor temperature estimation circuit 32 that estimates the shell discharge temperature and the motor temperature inside the compressor 1 and a primary resistance estimation circuit 31 that estimates the primary resistance of the motor inside the compressor 1 from the motor temperature are added. The result is the equivalent calculator 1
This is intended to be reflected in the calculation of the amount of secondary interlinkage magnetic flux in 7.

The flow of the primary resistance correction method will be described below.
This will be described with reference to FIGS. 3, 4, 5, and 6.

FIG. 3 is a Mollier diagram, in which the vertical axis represents pressure and the horizontal axis represents enthalpy. Shell discharge pressure P2 of compressor 1
It is understood that the motor temperature Mo can be estimated if the shell discharge temperature T2 is known.

The shell discharge pressure P2 of the compressor 1 detected by the shell discharge pressure detector 33 and the refrigerant flow rate G1 detected by the refrigerant flow rate detector 34 are input to the shell discharge temperature / motor temperature estimation circuit 32.

Shell discharge temperature / motor temperature estimation circuit 32
Then, the shell discharge temperature T2 is estimated from the characteristic indicating the relationship between the shell discharge pressure and the shell discharge temperature set for each refrigerant flow rate G0, G1, G2 of the compressor 1 set at the design stage as shown in FIG. In addition, the refrigerant flow rates G0, G1, G2 of the compressor 1 set at the design stage shown in FIG.
The motor temperature Mo is estimated from the characteristic indicating the relationship between the shell discharge temperature and the motor temperature set for each. This result is input to the primary resistance estimation circuit 31.

The primary resistance estimation circuit 31 calculates the primary resistance setting value R ^ s according to the characteristic indicating the relationship between the primary resistance and the motor temperature which is set at the design stage as shown in FIG.
The value is input to the equivalent calculator 17 to correct the temperature of the primary resistance.

As described above, according to the present embodiment, the sensors necessary for correcting the primary resistance need only be two kinds of sensors for detecting the shell discharge pressure of the compressor 1 and the refrigerant flow rate flowing in the discharge pipe, and Both types are easy to install, and the correlation between the refrigerant flow rate, the shell discharge pressure, and the shell discharge temperature, and the compressor 1
The primary resistance is corrected by utilizing the correlation characteristics between the internal motor temperature and the motor primary resistance, and the primary resistance Rs is calculated as a constant value in the calculation of the secondary flux linkage amount. Can be done.

Next, a second embodiment of the present invention will be described with reference to FIGS. 7, 8, 9 and 10.

In FIG. 7, 33 is a shell discharge pressure detector for detecting the discharge pressure of the compressor 1, 36 is a shell suction pressure detector for detecting the suction pressure of the compressor 1, and 37 is a suction temperature of the compressor 1. It is a shell suction temperature detector for detecting. The shell discharge pressure detector 33, the shell suction pressure detector 36, and the shell suction temperature detector 37 are the discharge end temperature /
It is connected to the motor temperature estimation circuit 35, and the discharge end temperature / motor temperature estimation circuit 35 is connected to the primary resistance estimation circuit 31.

In this embodiment, a shell discharge pressure detector 33 for detecting the discharge pressure of the compressor 1, a shell suction pressure detector 36 for detecting the suction pressure, a shell suction temperature detector 37 for detecting the suction temperature, A discharge end temperature / motor temperature estimation circuit 35 that estimates the discharge end temperature and the motor temperature inside the compressor 1 and a primary resistance estimation circuit 31 that estimates the primary resistance from the motor temperature are added, and the result is calculated by a considerable amount calculator 17 This is intended to be reflected in the calculation of the amount of secondary interlinkage magnetic flux in.

The flow of the primary resistance correction method will be described below.
This will be described with reference to FIGS. 9 and 10. FIG. 9 is a Mollier diagram, in which the vertical axis represents pressure and the horizontal axis represents enthalpy. Compressor 1
In order to accurately detect the motor temperature inside the compressor with respect to the load fluctuation, the discharge end pressure P2 and the discharge end temperature T3 of the compressor 1 are detected.
It can be understood that the motor temperature Mo can be estimated if the two points can be detected.

Therefore, the suction pressure P1 of the compressor 1 detected by the shell suction pressure detector 36 and the shell suction temperature detector 37 are detected.
The suction temperature T1 of the compressor 1 detected in step S1 and the discharge pressure P2 of the compressor 1 detected by the shell discharge pressure detector 33 are input to the discharge end temperature / motor temperature estimation circuit 35, and the discharge end temperature /
The motor temperature estimation circuit 35 estimates the discharge end temperature T3,
The estimated value Mo of the motor temperature is obtained from (Equation 7), and the obtained estimated value Mo of the motor temperature is input to the primary resistance estimation circuit 31. In (Equation 7), Mo is the motor temperature, T3 is the discharge end temperature, and ΔT is the correction coefficient set at the design stage.

The primary resistance estimation circuit 31 calculates the primary resistance setting value R ^ s from the characteristic indicating the relationship between the primary resistance and the motor temperature which is set in the design stage as shown in FIG. In 17, the temperature of the primary resistance is corrected in the calculation of the amount of secondary interlinkage magnetic flux.

As described above, according to the present embodiment, three types of sensors for detecting the discharge pressure, the suction pressure, and the suction temperature of the compressor 1 are required to correct the primary resistance. 1 By estimating the motor temperature from the internal discharge end temperature, the primary resistance correction can be detected accurately with respect to load fluctuations, so it reacts sensitively and accurately to load fluctuations in the system that are more detailed than before. It is possible to more accurately calculate the amount of secondary interlinkage magnetic flux.

Next, the third embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIGS. 1, 12, 13, and 14.

In FIG. 11, 37 is a shell suction temperature detector for detecting the suction temperature of the compressor 1, 36 is a shell suction pressure detector for detecting the suction pressure, and 38 is a shell discharge temperature detector for detecting the discharge temperature. Reference numeral 33 is a shell discharge pressure detector for detecting the discharge pressure.

The shell suction temperature detector 37, the shell suction pressure detector 36, the shell discharge temperature detector 38, and the shell discharge pressure detector 33 are connected to the discharge end temperature / motor temperature estimation circuit 39 shown in FIG. The discharge end temperature / motor temperature estimation circuit 39 is connected to the primary resistance estimation circuit 31.

In this embodiment, a shell suction temperature detector 37 for detecting the suction temperature of the compressor 1, a shell suction pressure detector 36 for detecting the suction pressure, a shell discharge temperature detector 38 for detecting the discharge temperature, A shell discharge pressure detector 33 for detecting the discharge pressure, a discharge end temperature / motor temperature estimation circuit 39 for estimating the discharge end temperature inside the compressor 1 and the motor temperature,
A primary resistance estimation circuit 31 that estimates the primary resistance of the motor inside the compressor 1 from the motor temperature is added, and the result is to be reflected in the calculation of the interlinkage secondary magnetic flux equivalent amount in the equivalent amount calculator 17. is there.

The flow of the primary resistance correction method will be described below.
This will be described with reference to FIGS. 13 and 14. FIG. 13 is a Mollier diagram, in which the vertical axis represents pressure and the horizontal axis represents enthalpy. In order to accurately detect the temperature of the motor inside the compressor 1 against load fluctuations, the discharge pressure P2 of the compressor 1 is used as the shell discharge temperature T2 and the discharge end temperature inside the compressor 1 By detecting two points of a certain T3, the motor temperature M
It can be seen that o can be accurately estimated.

Therefore, the shell suction temperature detector 37, the shell suction pressure detector 36, the shell discharge temperature detector 38, and the shell discharge pressure detector 33 detect the shell suction temperature T1 of the compressor 1, the shell suction pressure P1, and the shell discharge. The temperature T2 and the shell discharge pressure P2 are input to the discharge end temperature / motor temperature estimation circuit 39. In the discharge end temperature / motor temperature estimation circuit 39, the shell suction temperature T1, the shell suction pressure P1,
In addition to estimating the discharge end temperature T3 from the shell discharge pressure P2, the calculation shown in (Equation 8) is performed to estimate the motor temperature Mo.

[0063]

[Equation 8]

In (Equation 8), T2 is the shell discharge temperature, T3 is the discharge end temperature inside the compressor 1, and M is a constant set at the design stage.

The discharge end temperature / motor temperature estimation circuit 3
The motor temperature Mo which is the output of 9 is the primary resistance estimation circuit 3
Input to 1.

In the primary resistance estimation circuit 31, the primary resistance set value R ^ s is calculated from the characteristic showing the relationship between the primary resistance set value and the motor temperature shown in FIG. In step 17, the temperature of the primary resistance is corrected.

As described above, according to this embodiment, four types of sensors for detecting the suction temperature of the compressor 1, the suction pressure, the discharge temperature and the discharge pressure are provided for the correction of the primary resistance. Although required, the primary resistance correction can be detected accurately with respect to load fluctuations, and in addition to responding sensitively and accurately to the load fluctuations of the detailed system, the temperature of the motor inside the compressor 1 can be shelled out. Since the estimated temperature range can be narrowed by estimating from the discharge temperature and the discharge end temperature inside the compressor 1, the estimated value of the primary resistance itself becomes more accurate, and the calculation of the secondary flux linkage equivalent amount is performed with high accuracy. You can

Since the shell suction temperature, shell suction pressure, shell discharge temperature, and shell discharge pressure in the first, second, and third embodiments are used in the system control of the air conditioner,
It can be used also as the correction control of the primary resistance of the present invention, and can be easily realized.

[0069]

As described above, according to the present invention, a compressor whose rotational speed is controlled by a three-phase power amplifier, a current detector which detects the primary current of the compressor, and a vector control which performs vector control of a power converter. In addition to the command calculation circuit, the shell discharge pressure detector for detecting the shell discharge pressure of the compressor and the refrigerant flow rate detector for detecting the refrigerant flow rate in the shell discharge pipe of the compressor output from the shell discharge pressure detector. Signal and the information of the output signal of the refrigerant flow rate detector, and estimates the shell discharge temperature, further estimates the motor temperature inside the compressor from the shell discharge temperature and the refrigerant flow rate, a shell discharge temperature / motor temperature estimation circuit, and the estimated motor By providing a primary resistance estimation circuit that estimates the primary resistance of the motor inside the compressor from the temperature, the sensor required for correcting the primary resistance is Only two types are required to detect the flow rate of the refrigerant flowing inside, and both types are easy to install, and the correlation between the refrigerant flow rate, the shell discharge pressure and the shell discharge temperature, the temperature of the motor inside the compressor and the motor primary resistance The primary resistance can be corrected by utilizing the correlation characteristic of No. 1, and the calculation of the secondary flux linkage equivalent amount can be accurately performed unlike the conventional calculation in which the primary resistance is set to a constant value.

From the shell discharge pressure detector for detecting the discharge pressure of the compressor, the shell suction pressure detector for detecting the suction pressure of the compressor, and the shell suction temperature detector for detecting the suction temperature of the compressor, The discharge end temperature inside the compressor is estimated by the information of the output signal of the shell discharge pressure detector, the output signal of the shell suction pressure detector, and the output signal of the shell suction temperature detector, and the estimated discharge end temperature is estimated. A discharge end temperature / motor temperature estimation circuit that estimates the motor temperature inside the compressor from the temperature, and a primary resistance estimation circuit that estimates the primary resistance of the motor inside the compressor from the estimated motor temperature inside the compressor Therefore, three types of sensors, that is, the detection of the discharge pressure of the compressor 1, the detection of the suction pressure, and the detection of the suction temperature are necessary for the correction of the primary resistance. Because it accurately detect the load variation correction of the primary resistance by estimating Luo motor temperature,
Compared to the conventional system, it reacts sensitively and finely to small load fluctuations in the system, and can calculate the secondary flux linkage equivalent amount more accurately to small load fluctuations.

Further, a shell discharge pressure detector for detecting a discharge pressure of the compressor, a shell suction pressure detector for detecting a suction pressure of the compressor, a shell suction temperature detector for detecting a suction temperature of the compressor, and the above From the shell discharge temperature detector for detecting the discharge temperature of the compressor, the compressor is determined by the information of the output signal of the shell discharge pressure detector, the output signal of the shell suction pressure detector and the output signal of the shell suction temperature detector. A discharge end temperature / motor temperature estimation circuit that estimates the internal discharge end temperature and estimates the motor temperature inside the compressor based on the output signal of the shell discharge temperature detector and the estimated discharge end temperature information. A primary resistance estimation circuit that estimates the primary resistance of the motor inside the compressor from the motor temperature inside the compressor is provided. Four types of sensors are required to detect the suction temperature, the shell suction pressure, the shell discharge temperature, and the shell discharge pressure, but the primary resistance correction can be detected accurately with respect to load fluctuations. In addition to responding sensitively and accurately to system load fluctuations,
Since the estimated temperature range can be narrowed by estimating the temperature of the motor inside the compressor from the shell discharge temperature and the discharge end temperature inside the compressor, the estimated value of the primary resistance itself can be estimated more accurately, and the secondary linkage flux A considerable amount of calculation can be performed with high accuracy.

With these configurations, the primary resistance that changes with temperature is compensated, the control accuracy is prevented from being degraded by the change of the primary resistance, and an efficient air conditioner can be realized, and its practical effect is great. There is something.

Further, since the suction temperature, suction pressure, discharge temperature, and discharge pressure of the compressor are used in the system control of the air conditioner, they can be combined with the primary resistance compensation control of the present invention, and easily realized. It is possible.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an air conditioner according to a first embodiment of the present invention.

FIG. 2 is a block diagram of an inverter control device for an air conditioner according to the first embodiment of the present invention.

FIG. 3 is a Mollier diagram of the air conditioner according to the first embodiment of the present invention.

FIG. 4 shows the shell discharge temperature in the first embodiment of the present invention.
Characteristic diagram showing the relationship between the shell discharge pressure, shell discharge temperature, and refrigerant flow rate set in the motor temperature estimation circuit

FIG. 5: Shell discharge temperature in the first embodiment of the present invention
Characteristic diagram showing the relationship between the shell discharge temperature, motor temperature, and refrigerant flow rate set in the motor temperature estimation circuit

FIG. 6 is a characteristic diagram showing the relationship between the motor temperature and the primary resistance set in the primary resistance estimation circuit.

FIG. 7 is a schematic configuration diagram of an air conditioner according to a second embodiment of the present invention.

FIG. 8 is a block diagram of an inverter control device for an air conditioner according to a second embodiment of the present invention.

FIG. 9 is a Mollier diagram of the air conditioner according to the second embodiment of the present invention.

FIG. 10 is a characteristic diagram showing the relationship between the motor temperature set in the primary resistance estimation circuit and the primary resistance.

FIG. 11 is a schematic configuration diagram of an air conditioner according to a third embodiment of the present invention.

FIG. 12 is a block diagram of an inverter control device for an air conditioner according to a third embodiment of the present invention.

FIG. 13 is a Mollier diagram of the air conditioner according to the third embodiment of the present invention.

FIG. 14 is a characteristic diagram showing the relationship between the motor temperature and the primary resistance set in the primary resistance estimation circuit.

FIG. 15 is a schematic configuration diagram of an air conditioner in a conventional example.

FIG. 16 is a block diagram of a slip frequency type vector control inverter device for an air conditioner in a conventional example.

[Explanation of symbols]

 1 Compressor 31 Primary Resistance Estimation Circuit 32 Shell Discharge Temperature / Motor Temperature Estimation Circuit 33 Shell Discharge Pressure Detector 34 Refrigerant Flow Rate Detector 35 Discharge End Temperature / Motor Temperature Estimation Circuit 36 Shell Suction Pressure Detector 37 Shell Suction Temperature Detector 38 Shell discharge temperature detector 39 Discharge end temperature / motor temperature estimation circuit

Claims (3)

[Claims] 1. A compressor whose rotation speed is controlled by a power converter, and a current detector which detects a primary current of the compressor.
A shell that estimates the shell discharge temperature and the motor temperature from the output signal of the shell discharge pressure detector that detects the discharge pressure of the compressor and the output signal of the refrigerant flow rate detector that detects the refrigerant flow rate in the shell discharge pipe of the compressor Discharge temperature / motor temperature estimation circuit, primary resistance estimation circuit that estimates the primary resistance of the motor from the output signals of the shell discharge temperature / motor temperature estimation circuit, and drives the power converter from the output signal of the primary resistance estimation circuit The vector control command calculation circuit corrects the temperature change of the primary resistance of the motor, which is the calculation element of the vector control command, by the output signal of the primary resistance estimation circuit. An air conditioner characterized by compensating for deterioration of vector control characteristics due to changes. 2. A compressor whose rotation speed is controlled by a power converter, and a current detector which detects a primary current of the compressor.
Output signal of shell discharge pressure detector for detecting shell discharge pressure of the compressor, output signal of shell suction pressure detector for detecting shell suction pressure of the compressor, and shell suction for detecting shell suction temperature of the compressor A discharge end temperature / motor temperature estimation circuit for estimating the discharge end temperature and the motor temperature inside the compressor from the output signal of the temperature detector, and an output signal inside the compressor from the output signal of the discharge end temperature / motor temperature estimation circuit. A primary resistance estimation circuit for estimating the primary resistance of the motor,
The vector control command calculation circuit drives the power converter from the output signal of the primary resistance estimation circuit, and the vector control command calculation circuit calculates the vector control command by the output signal of the primary resistance estimation circuit. An air conditioner characterized by compensating for a change in temperature of a primary resistance of a motor, which is an element, and compensating for a decrease in vector control characteristics due to a temperature change. 3. A compressor whose rotation speed is controlled by a power converter, and a current detector which detects a primary current of the compressor.
Output signal of shell discharge pressure detector for detecting shell discharge pressure of the compressor, output signal of shell suction pressure detector for detecting shell suction pressure of the compressor, and shell suction for detecting shell suction temperature of the compressor Estimating the discharge end temperature inside the compressor from the output signal of the temperature detector, the discharge inside temperature of the compressor from the output signal of the shell discharge temperature detector for detecting the discharge end temperature and the shell discharge temperature of the compressor A discharge end temperature / motor temperature estimation circuit for estimating a motor temperature, a primary resistance estimation circuit for estimating a primary resistance of a motor inside the compressor from an output signal of the discharge end temperature / motor temperature estimation circuit, and the primary resistance estimation A vector control command calculation circuit for driving the power converter from an output signal of the circuit, wherein the vector control command calculation circuit is the primary resistor. The temperature variation of the primary resistance of the motor is an operation element of the vector control command corrected by the output signal of Teikairo, air conditioner, characterized in that to compensate for the reduction of the vector control characteristics due to a temperature change.