JP3270542B2 - Air conditioner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

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

As an inverter control method for a general-purpose inverter, vector control is often employed because excellent responsiveness and power saving can be obtained. Therefore, in recent years, vector control has also been applied to a variable speed control method for a compressor of an air conditioner.

The vector control method includes a magnetic flux detection type vector control method that detects a secondary magnetic flux as a vector amount and uses the primary magnetic flux as a control signal of a primary current, and a slip frequency type vector that calculates and controls a magnetic flux vector based on a motor constant. Control schemes are known.

[0005] As a technique relating to the conventional slip frequency type vector control method, for example, Japanese Patent Application Laid-Open No. Sho 64-04309 is disclosed.
There is one disclosed in Japanese Patent Publication No. 7 (JP-A) No. 7.

Referring to the drawings, an example of the operation of the prior art will be described with reference to FIGS.

FIG. 15 is a configuration 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 decompression device, and 5 is an outdoor heat exchanger. These are connected in a ring to form a refrigeration circuit. ing.

Reference numeral 6 denotes an indoor fan, and 7 denotes an outdoor fan.
Reference numeral 8 denotes an inverter control device for controlling the rotation speed of the compressor 1, and reference numeral 9 denotes 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 * viewed on a rectangular coordinate axis (de-qe axis) rotating at a primary angular frequency ω,
vqes * (subscripts des * and qes * are de axes,
a three-phase power amplifier 13 and a coordinate converter 1 which represent a primary component on the qe axis) into three-phase AC.
4 constitutes a power supply device.

Reference numeral 15 denotes a three-phase alternating current iu as a primary current,
A coordinate converter for converting iv, iw into an excitation current ides, which is a primary current on the de-qe axis, and a torque current iqes, 16 is a three-phase AC voltage vu, vv, v which is a primary voltage
w is a coordinate converter that converts w into primary voltages vdes and vqes on the de-qe axis.
r, λ｀qer (subscripts der and qer are de axes,
(representing a quadratic component on the qe axis).

Reference numeral 18 denotes an estimated value λ ＾ der of the secondary flux linkage in a vector-controlled state and an estimated value p of the slip angular frequency.
＾ ωs is converted to coordinates, ie, outputs, iqe
s and the magnetic flux / slip angular frequency estimator which is calculated from the secondary resistance constant R ＾ r, and 19 is an estimated value λ of a secondary flux linkage equivalent amount.
推定 der and λ ＾ ｀ qer are calculated from λ 演算 der which is the output of the magnetic flux / slip angular frequency estimator 18 and the primary angular frequency ω. The estimated value p ＾ ωr is calculated by using λ｀der and λ｀qer, which are the outputs of the corresponding quantity calculator 17, and the secondary resistance constant R
＾ r and λ ＾ ｀ qer which is the output of the estimated value calculator 19,
This is a rotational angular velocity estimator that calculates from λ ＾ ｀ der and p ＾ ωs that is the output of the magnetic flux / slip angular frequency estimator.

An adder 23 adds p ＾ ωr output from the rotational angular velocity estimator 20 and p ＾ ωs output from the magnetic flux / slip angle frequency estimator to obtain a primary angular frequency ω. The integrator 22 integrates the frequency ω to obtain the phase θ.
6 is a trigonometric function generator for obtaining sin θ and cos θ to be input to 6.

Numeral 24 denotes a subtractor for subtracting ides output from the coordinate converter 15 from the exciting current command value ides *, 2
Reference numeral 5 denotes a subtractor for subtracting iqes, 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 calculates the primary voltages vdes, v
qes, the primary currents ides, iqes, the primary resistance set value R ＾ s, and the primary angular frequency ω are input, and 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 primary resistance set values of the induction motor inside the compressor 1, primary inductance, secondary inductance, mutual inductance, leakage coefficient, and P are differential operators, T is a time constant of the first-order lag.

The magnetic flux / slip angular frequency estimator 18 receives the primary currents ides and iqes and the secondary resistance set value R ＾ r (Equation 2), and the secondary chain in a vector-controlled state based on (Equation 3). An estimated value λ ＾ der of the intersecting 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 set value of the induction motor inside the compressor 1. The estimated value calculator 19 receives the estimated value λ ＾ der of the secondary flux linkage and the primary angular frequency ω,
Estimated value λ４d of secondary flux linkage equivalent based on (Equation 4)
er, λ ＾ ｀ qer are calculated.

[0024]

(Equation 4)

The rotational angular velocity estimator 20 calculates the secondary flux linkage equivalents λ｀der, λ｀qer and the secondary flux linkage equivalents λ ＾ ｀ der, λ ＾ ｀ qer, and the slip angular frequency estimate. p ＾ ωs is input, and an 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 of the rotational angular velocity p ＾ ωr and the estimated value of the slip angular frequency p ＾ ωs to output a primary angular frequency ω. The integrator 21 integrates the primary angular frequency ω and outputs a phase signal θ. The trigonometric function generator 22 receives the phase signal θ and outputs the corresponding sine and cosine.

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

[0029]

Since the conventional slip frequency type vector control device is configured as described above,
In an actual induction motor inside a compressor, the primary resistance value Rs is changed from 0 ° C. to 1 depending on conditions such as a load condition and an ambient temperature.
Since the resistance changes up to about 20 ° C., the resistance fluctuates up and down by about 20% based on the resistance value at 60 ° C., for example.
Secondary flux linkage equivalent amount λ｀der, λ represented by (Equation 1)
The arithmetic expression of ｀ qer becomes (Equation 6) when the differential term is omitted in a steady state.

[0030]

(Equation 6)

The estimated value of the slip angular frequency p 角 ωs in the steady state is (Equation 7) from (Equation 2) and (Equation 3), ignoring the differential term.

[0032]

(Equation 7)

(Equation 6) includes the primary resistance set value R ＾ s. Therefore, the temperature change between the primary resistance set value R ＾ s and the actual primary resistance Rs of the induction motor inside the compressor 1 due to temperature fluctuation. If an error occurs, the secondary flux linkage equivalent λ｀der, λ
The calculation accuracy of ｀ qer deteriorates. Further, in (Equation 6), in the low-speed region, | ωσLs |
Since s is sufficiently smaller than s, the error of the error of the primary resistance value Rs has a greater effect on the calculation of the secondary flux linkage equivalents λ｀der and λ｀qer. Therefore, the rotational angular velocity estimator 20 represented by (Equation 5) is equivalent to the secondary flux linkage equivalent amount λ｀der,
Since λ｀qer is included, an estimation error occurs in the estimated value of the rotational angular velocity p ＾ ωr due to the temperature fluctuation of the primary resistance value Rs, and there is a problem to be solved such that the control becomes unstable especially in a low-speed region. .

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

[0035]

In order to achieve the above object, an air conditioner according to the present invention comprises a compressor whose rotation speed is controlled by a power converter, and a current detector for detecting a primary current of the compressor. Estimating a shell discharge temperature and a motor temperature from an output signal of a shell discharge pressure detector that detects a discharge pressure of the compressor and an output signal of a refrigerant flow detector that detects a refrigerant flow rate in a shell discharge pipe of the compressor. A shell discharge temperature / motor temperature estimating circuit, a primary resistance estimating circuit for estimating a primary resistance of a motor from an output signal of the shell discharging temperature / motor temperature estimating circuit, and the three-phase power amplifier from an output signal of the primary resistance estimating circuit. It is constituted by a vector control command calculation circuit to be driven, and a primary resistance of a motor which is a calculation element of a vector control command is determined by an 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.

Further, an output signal of a shell discharge pressure detector for detecting a shell discharge pressure of the compressor, an output signal of a shell suction pressure detector for detecting a shell suction pressure of the compressor, and a shell suction temperature of the compressor. A discharge end temperature / motor temperature estimating circuit for estimating a discharge end temperature and a motor temperature inside the compressor from an output signal of a shell suction temperature detector for detecting a discharge end temperature / motor temperature estimating circuit. A primary resistance estimating circuit for estimating a primary resistance of a motor inside the compressor, and a vector control instruction calculating circuit for driving the three-phase power amplifier from an output signal of the primary resistance estimating circuit; And a primary resistance estimating circuit for compensating for a change in the primary resistance of the motor due to the temperature, which is an element of the above calculation.

Further, an output signal of a shell discharge pressure detector for detecting a shell discharge pressure of the compressor, an output signal of a shell suction pressure detector for detecting a shell suction pressure of the compressor, and a shell suction pressure of the compressor. A discharge end temperature inside the compressor is estimated from an output signal of a shell suction temperature detector for detecting a temperature, and a motor temperature inside the compressor is estimated from the discharge end temperature and an output signal of the shell discharge temperature detector. A discharge end temperature / motor temperature estimating circuit, a primary resistance estimating circuit for estimating a primary resistance of a motor inside the compressor from an output signal of the discharge end temperature / motor temperature estimating circuit, and an output signal of the primary resistance estimating circuit. It is constituted by a vector control command operation circuit for driving the three-phase power amplifier. And a primary resistance estimating circuit to compensate for changes caused by.

[0038]

According to the present invention, the primary resistance Rs, which changes with temperature, is compensated for by the above-described configuration to prevent a decrease in control accuracy due to a change in the primary resistance, and an efficient air conditioner can be realized.

[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. Components having the same configuration as the conventional example are denoted by the same reference numerals, and description thereof is omitted.

FIG. 1, FIG. 2, FIG. 3, FIG. 4, FIG.
1 shows a first embodiment of the present invention. In FIG. 1, reference numeral 33 denotes a shell discharge pressure detector for detecting a shell discharge pressure of the compressor 1, and reference numeral 34 denotes a refrigerant flow detector for detecting a refrigerant flow rate in a shell discharge pipe of the compressor 1. The heater 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.

A secondary flux linkage equivalent amount λ represented by (Equation 1)
The arithmetic expressions of ｀ der and λ｀qer are (Equation 6) when the differential term is omitted in a steady state.

Since the equation (6) includes the primary resistance set value R ＾ s, an error occurs due to temperature fluctuation between the primary resistance value R ＾ s and the actual primary resistance value Rs of the induction motor inside the compressor 1. Occurs, the secondary flux linkage equivalent λ｀der, λ｀q
The calculation accuracy of er deteriorates. Further, in (Equation 6), in the low-speed region, | ωσLs |
Therefore, the error of the primary resistance value Rs has a greater influence on the calculation of the secondary flux linkage equivalents λ｀der and λ｀qer. Accordingly, the rotational angular velocity estimator 20 expressed by (Equation 5) is equivalent to the secondary flux linkage equivalent amount λ｀de.
Since r and λ｀qer are included, an estimation error occurs in the estimated value of the rotational angular velocity p ＾ ωr due to the temperature fluctuation of the primary resistance value Rs. I do.

In this embodiment, a shell discharge pressure detector 33 for detecting the shell discharge pressure of the compressor 1, a refrigerant flow detector 34 for detecting a refrigerant flow in the shell discharge pipe of the compressor 1,
A shell discharge temperature / motor temperature estimating circuit 32 for estimating the shell discharge temperature and the motor temperature inside the compressor 1 and a primary resistance estimating circuit 31 for estimating the primary resistance of the motor inside the compressor 1 from the motor temperature are added. Compute the result by a considerable amount
7 is intended to be reflected in the calculation of the amount of secondary linkage flux.

Hereinafter, the flow of the method of correcting the primary resistance will be described.
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
If the shell discharge temperature T2 is known, the motor temperature Mo can be estimated.

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 detector 34 are input to a 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 of the refrigerant flow rates G0, G1, and G2 of the compressor 1 set at the design stage as shown in FIG. Further, 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 estimating circuit 31 calculates a primary resistance set value R ＾ s from a characteristic indicating the relationship between the primary resistance and the motor temperature set at the design stage as shown in FIG.
The correction amount is input to the computing unit 17 to correct the temperature of the primary resistance.

As described above, according to this embodiment, the sensors required for correcting the primary resistance need only be of two types that detect the discharge pressure of the shell of the compressor 1 and the flow rate of the refrigerant flowing in the discharge pipe. All types are easy to install, the correlation between the refrigerant flow rate, the shell discharge pressure and the shell discharge temperature, and the compressor 1
Correction of the primary resistance using the correlation characteristics between the temperature of the internal motor and the motor's primary resistance, and in the calculation of the amount of secondary flux linkage equivalent to the calculation in which the primary resistance Rs is a fixed value compared to the conventional method. 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 the suction temperature of the compressor 1. Is a shell suction temperature detector for detecting the temperature. The shell discharge pressure detector 33, the shell suction pressure detector 36, and the shell suction temperature detector 37 correspond to the discharge end temperature
The discharge temperature / motor temperature estimating circuit 35 is connected to the primary resistance estimating 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 estimating circuit 35 for estimating a discharge end temperature and a motor temperature inside the compressor 1 and a primary resistance estimating circuit 31 for estimating a primary resistance from the motor temperature are added. Is intended to be reflected in the calculation of the amount of secondary interlinkage magnetic flux in.

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

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

The primary resistance estimating circuit 31 calculates the primary resistance set value R ＾ s from the characteristic indicating the relationship between the primary resistance and the motor temperature set at the design stage as shown in FIG. At 17, the temperature of the primary resistance is corrected in the calculation of the amount of secondary flux linkage.

As described above, according to the present embodiment, three types of sensors, ie, the detection of the discharge pressure of the compressor 1, the detection of the suction pressure, and the detection of the suction temperature, are required to correct the primary resistance. (1) By estimating the motor temperature from the internal discharge end temperature, the correction of the primary resistance can be accurately detected with respect to the load fluctuation. The calculation of the amount of secondary linkage flux can be performed more accurately.

Next, a 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, reference numeral 37 denotes a shell suction temperature detector for detecting the suction temperature of the compressor 1, 36 a shell suction pressure detector for detecting the suction pressure, and 38 a shell discharge temperature detector for detecting the discharge temperature. Reference numeral 33 denotes a shell discharge pressure detector for detecting a 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 a discharge end temperature / motor temperature estimation circuit 39 in FIG. The discharge end temperature / motor temperature estimating circuit 39 is connected to the primary resistance estimating 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 a discharge pressure, a discharge end temperature / motor temperature estimation circuit 39 for estimating a discharge end temperature and a motor temperature inside the compressor 1,
A primary resistance estimating circuit 31 for estimating the primary resistance of the motor inside the compressor 1 from the motor temperature is added, and the result is reflected in the calculation of the interlinkage secondary magnetic flux equivalent in the equivalent calculator 17. is there.

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

Therefore, the shell suction temperature T1, the shell suction pressure P1, and the shell discharge pressure of the compressor 1 detected by 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 detected. 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 estimating 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, a 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 estimating circuit 3
9 is the output of the motor temperature Mo, the primary resistance estimating circuit 3
1 is input.

The primary resistance estimating circuit 31 calculates a primary resistance set value R ＾ s based on the characteristic indicating the relationship between the primary resistance set value and the motor temperature shown in FIG. At 17, a correction is made for the temperature of the primary resistance.

As described above, according to the present embodiment, four types of sensors for detecting the suction temperature of the compressor 1, detecting the suction pressure, detecting the discharge temperature, and detecting the discharge pressure are used to correct the primary resistance. Although it is necessary, the primary resistance correction can be accurately detected with respect to the load fluctuation, and in addition to responding precisely and precisely to the fine system load fluctuation, the temperature of the motor inside the compressor 1 is controlled by the shell. Since the estimated temperature range can be narrowed by estimating 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. I can do it.

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

[0069]

As described above, the present invention provides a compressor whose rotation speed is controlled by a three-phase power amplifier, a current detector for detecting a primary current of the compressor, and a vector control for performing vector control of a power converter. In addition to the command operation circuit, the output of the shell discharge pressure detector is output from a shell discharge pressure detector that detects a shell discharge pressure of the compressor and a refrigerant flow detector that detects a refrigerant flow rate in a shell discharge pipe of the compressor. A shell discharge temperature / motor temperature estimating circuit for estimating a shell discharge temperature based on a signal and information on an output signal of the refrigerant flow rate detector and further estimating a motor temperature inside the compressor from the shell discharge temperature and the refrigerant flow rate; By providing a primary resistance estimating circuit for estimating the primary resistance of the motor inside the compressor from the temperature, the sensor necessary for correcting the primary resistance can detect the discharge pressure and discharge pressure of the compressor. 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 motor temperature inside the compressor and the motor primary resistance The correction of the primary resistance is performed by utilizing the correlation characteristic of the above, and the calculation of the secondary flux linkage equivalent amount can be performed accurately, unlike the conventional case where the calculation is performed with the primary resistance being a constant value.

Further, a shell discharge pressure detector for detecting the discharge pressure of the compressor, a shell suction pressure detector for detecting the suction pressure of the compressor, and a shell suction temperature detector for detecting the suction temperature of the compressor, A discharge end temperature inside the compressor is estimated based on information of an output signal of the shell discharge pressure detector, an output signal of the shell suction pressure detector, and an output signal of the shell suction temperature detector, and the estimated discharge end A discharge end temperature / motor temperature estimating circuit for estimating a motor temperature inside the compressor from a temperature; and a primary resistance estimating circuit for estimating a 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 required 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 prior art, it responds more sensitively and more accurately to load fluctuations in the system, and can calculate the secondary flux linkage equivalent amount more accurately for fine 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, From the shell discharge temperature detector for detecting the discharge temperature of the compressor, the output signal of the shell discharge pressure detector, the output signal of the shell suction pressure detector, and the information of the output signal of the shell suction temperature detector, the compressor A discharge end temperature / motor temperature estimating circuit for estimating a motor temperature inside the compressor based on an output signal of the shell discharge temperature detector and information on the estimated discharge end temperature, estimating an internal discharge end temperature; A primary resistance estimating circuit for estimating the primary resistance of the motor inside the compressor from the motor temperature inside the compressor, so as to correct the primary resistance. 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 reacting to system load fluctuation sensitively and accurately,
The estimated temperature range can be narrowed by estimating the motor temperature inside the compressor from the shell discharge temperature and the discharge end temperature inside the compressor, so that 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 to prevent the control accuracy from being reduced by the change in the primary resistance, and an efficient air conditioner can be realized, and its practical effect is large. 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 also be used for the compensation control of the primary resistance of the present invention and can be easily realized. It is possible.

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

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

FIG. 6 is a characteristic diagram showing a relationship between a motor temperature and a primary resistance set in a 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 of an air conditioner according to a second embodiment of the present invention.

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

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

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 of an air conditioner according to a third embodiment of the present invention.

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

FIG. 14 is a characteristic diagram illustrating a relationship between a motor temperature and a primary resistance set in a 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 of an air conditioner in a conventional example.

[Description of Signs] 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

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F25B 1/00 F24F 11/02 102 F04B 49/06 341

Claims (3)

(57) [Claims] 1. A compressor whose rotation speed is controlled by a power converter, a current detector for detecting a primary current of the compressor,
A shell for estimating a shell discharge temperature and a motor temperature from an output signal of a shell discharge pressure detector for detecting a discharge pressure of the compressor and an output signal of a refrigerant flow detector for detecting a refrigerant flow rate in a shell discharge pipe of the compressor. A discharge temperature / motor temperature estimating circuit, a primary resistance estimating circuit for estimating a primary resistance of a motor from an output signal of the shell discharge temperature / motor temperature estimating circuit, and driving the power converter from an output signal of the primary resistance estimating 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, based on the output signal of the primary resistance estimation circuit, An air conditioner characterized by compensating for a decrease in vector control characteristics due to a change. 2. A compressor whose rotation speed is controlled by a power converter, a current detector for detecting a primary current of the compressor,
An output signal of a shell discharge pressure detector for detecting a shell discharge pressure of the compressor, an output signal of a shell suction pressure detector for detecting a shell suction pressure of the compressor, and a shell suction for detecting a shell suction temperature of the compressor. A discharge end temperature / motor temperature estimating circuit for estimating a discharge end temperature and a motor temperature inside the compressor from an output signal of a temperature detector, and an internal circuit of the compressor based on an output signal of the discharge end temperature / motor temperature estimation circuit. A primary resistance estimating circuit for estimating a primary resistance of the motor;
A vector control command calculation circuit for driving the power converter from an output signal of the primary resistance estimation circuit, wherein the vector control command calculation circuit calculates a vector control command based on an output signal of the primary resistance estimation circuit. An air conditioner characterized by correcting a temperature change of a primary resistance of a motor as an element and compensating for a decrease in a vector control characteristic due to a temperature change. 3. A compressor whose rotation speed is controlled by a power converter, a current detector for detecting a primary current of the compressor,
An output signal of a shell discharge pressure detector for detecting a shell discharge pressure of the compressor, an output signal of a shell suction pressure detector for detecting a shell suction pressure of the compressor, and a shell suction for detecting a shell suction temperature of the compressor. Estimating the discharge end temperature inside the compressor from the output signal of the temperature detector, and detecting the discharge end temperature and the shell discharge temperature of the compressor from the output signal of the shell discharge temperature detector to detect the inside 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 a 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 includes 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.