JPWO2016051456A1 - Winding switching motor driving apparatus, winding switching motor driving control method, and refrigeration air conditioning equipment using them - Google Patents

Abstract

A motor drive circuit 1 for driving the permanent magnet synchronous motor 3, a winding switching circuit 2 for switching the connection of the windings of the permanent magnet synchronous motor 3, and a control for controlling the motor drive circuit 1 and the winding switching circuit 2 Circuit 4, the motor drive circuit 1 stops the permanent magnet synchronous motor 3 under the control of the control circuit 4, and the winding switching circuit 2 is controlled with the permanent magnet synchronous motor 3 under the control of the control circuit 4. When the motor drive circuit 1 restarts the permanent magnet synchronous motor 3 under the control of the control circuit 4, the control circuit 4 starts the motor current initial of the permanent magnet synchronous motor 3. The value is set to be equal to or greater than the motor current value calculated from the motor current value before stopping and the wiring connection state.

Description

  The present invention relates to a winding switching motor driving device that drives a permanent magnet synchronous motor at a variable speed, a drive control method for the winding switching motor (permanent magnet synchronous motor), and a refrigeration and air conditioning apparatus using them.

Permanent magnet synchronous motors (as appropriate, also simply referred to as “motors”) have higher efficiency than induction motors, and thus have a wide range of applications from home appliances to industrial equipment or electric vehicle fields.
In addition, devices equipped with the motor are required to have high efficiency in a low and medium speed range (light load) in accordance with the trend of global warming prevention and energy saving. At the same time, in order to improve the usability (comfort) of the device, it is also required to expand the drive range in a high speed region (high load).
For example, in the case of a room air conditioner for home appliances, an improvement in annual energy consumption efficiency (annual performance factor, hereinafter referred to as “APF” where appropriate), which is an energy saving index, and an outside temperature of 2 ° C., which is an index for higher output. There is a need to improve both the heating capacity (hereinafter referred to as “low temperature heating capacity”).
In addition, a main machine such as an electric vehicle is in an operation state of low speed and large torque and high speed and small torque, and high efficiency is required under these operation conditions.

The following technologies are available for these requests and requests.
As a means for improving the efficiency (especially in the low and medium speed range) by the motor drive device, there is a low speed design of the motor by increasing the magnet amount and the winding amount.

Further, as a means for expanding the high-speed driving area of a motor designed at a low speed, there is a method of boosting a DC voltage in the motor driving device.
Patent Document 1 describes a technique in which a motor is stopped and a motor switch is switched by a mechanical switch while a load of an air conditioner, that is, a room temperature is stable near a set temperature.

Further, in relation to Patent Document 1, there are Patent Documents 2, 3, and 4 as related techniques of the restarting means of the compressor having a differential pressure when the motor is stopped.
Patent Document 2 describes a technique for reducing a differential pressure by reversing the compressor when stopped in a scroll compressor.
Patent Document 3 describes a technique in a reciprocating compressor in which a compressor load is estimated from a motor current value during synchronous operation (during open loop control) and used as a current command value during sensorless operation. Yes.
Patent Document 4 describes a technique that does not use synchronous operation by applying the fact that the position of the rotor can be detected even when the motor is stopped by detecting the terminal voltage when a pulse is applied. Has been.

  Patent Document 5 discloses a technology of an air conditioner that includes a permanent magnet synchronous motor in which coils are variable in series and in parallel, and selects connection of the motor coil according to a deviation between a set temperature of the indoor unit and a room temperature. Is described.

JP 2008-178207 A JP 2004-011473 A JP 2012-249355 A JP 2013-0555744 A Japanese Patent No. 5501132

However, the low-speed design method of the motor that increases the magnet amount and winding amount of the permanent magnet synchronous motor described above increases the induced voltage generated in the high-speed region, so that the drivable region becomes narrow and the efficiency in the high-speed region is reduced. There is a problem of a significant drop.
In addition, the above-described method of simply boosting the DC voltage of the motor drive device requires an additional circuit for boosting the DC voltage, which causes problems such as an increase in circuit scale and an increase in loss of the booster circuit.

In addition, the technique for switching the motor windings disclosed in Patent Document 1 between series connection and parallel connection has a problem that the timing (switching conditions) for switching the motor windings is limited. In addition, if the differential pressure of the compressor (the difference between the discharge pressure and the suction pressure) is large at the time of restart, the load torque applied to the motor will increase, and the motor may not be able to start, so the differential pressure of the compressor will be low There is a problem that the compressor needs to be stopped up to a long time, and the stop time at the time of winding switching becomes long. Also, depending on the environmental conditions, there is a problem that the room temperature changes greatly during the stop time, which makes the user uncomfortable.
In addition, the technology for ensuring restart by eliminating the differential pressure of the compressor disclosed in Patent Document 2 is a waste of energy when considered as an air conditioner system to eliminate the differential pressure of the compressor. There is. That is, in order to ensure the capacity of the air conditioner before stopping, it is necessary to increase the pressure difference before stopping again, and energy is wasted correspondingly. Furthermore, since the output of the air conditioner also decreases until the differential pressure returns to the value before stopping, there is a problem that the room temperature cannot be stably controlled and uncomfortable.

Moreover, since the technique disclosed in Patent Document 3 estimates the load during the synchronous operation at the time of startup, there is a problem that it cannot be applied unless the synchronous operation is stable. In other words, in order to start reliably, since it starts at the maximum current of the drive circuit during synchronous operation, it may become overtorque depending on the state of the differential pressure (when the differential pressure is small). There's a problem.
In addition, the technique disclosed in Patent Document 4 may accelerate rapidly or accelerate slowly depending on the setting of the initial current value at startup. That is, there is a problem that control cannot be performed at a desired acceleration rate.

  Moreover, the technique disclosed in Patent Document 5 has a problem that the stop time when the motor is switched from series (parallel) to parallel (series) is relatively long, and the transient characteristic change of the air conditioner during the stop period is a problem. There is a possibility.

  Accordingly, an object of the present invention is to achieve both high efficiency in the low and medium speed range and expansion of the drive range in the high speed range, and a motor that can be stably restarted in a short time while maintaining the differential pressure of the compressor. A drive device, a drive control method thereof, and a refrigerating and air-conditioning apparatus using them.

In order to solve the above problems, the present invention is configured as follows.
That is, the winding switching motor driving device of the present invention includes a motor driving circuit that drives a permanent magnet synchronous motor, a winding switching circuit that switches connection of windings of the permanent magnet synchronous motor, the motor driving circuit, and the winding. A control circuit for controlling a line switching circuit, wherein the motor driving circuit stops the permanent magnet synchronous motor by the control of the control circuit, and the winding switching circuit is controlled by the control circuit When the motor driving circuit restarts the permanent magnet synchronous motor by the control of the control circuit, the control circuit sets the initial value of the motor current of the permanent magnet synchronous motor before the stop. And the motor current value calculated from the connection state of the windings.

  Other means will be described in the embodiment for carrying out the invention.

  According to the present invention, a motor drive device that achieves both high efficiency in the low and medium speed range and expansion of the drive range in the high speed range and stably restarts in a short time while maintaining the differential pressure of the compressor. , Its drive control method, and refrigerating and air-conditioning equipment using them.

It is a figure which shows the example of a structure of the coil | winding switching motor drive device which concerns on 1st Embodiment of this invention, the motor which a coil switching motor drive device drive-controls, and the whole structure of the compressor which a motor drives, and a relationship. . It is a figure which shows the structural example of the motor drive circuit of the coil | winding switching motor drive device which concerns on 1st Embodiment of this invention. The figure which shows the internal structural example of the coil | winding switching circuit of the coil | winding switching motor drive device which concerns on 1st Embodiment of this invention, the connection relationship with each winding of a motor, and the connection relationship with the connection terminal of a motor drive circuit. It is. It is a figure which shows the state by which the winding of the motor switched by the coil | winding switching circuit of the coil | winding switching motor drive device which concerns on 1st Embodiment of this invention, (a) is the state in which the winding of each phase was connected in series (B) is a figure which shows the state which each coil | winding of each phase became parallel. It is a block diagram which shows the structural example of the process of the control circuit of the coil | winding switching motor drive device which concerns on 1st Embodiment of this invention. It is a block diagram which shows the structural example of the process inside the Iq ^* setting process of the control circuit of the coil | winding switching motor drive device which concerns on 1st Embodiment of this invention. It is a flowchart which shows the operation example of the Iq ^* setting process of the control circuit of the coil | winding switching motor drive device which concerns on 1st Embodiment of this invention. It is a flowchart which shows the operation example of the Id ^* setting process of the control circuit of the coil | winding switching motor drive device which concerns on 1st Embodiment of this invention. It is a flowchart which shows the operation example of the electricity supply system switch determination process of the control circuit of the coil | winding switching motor drive device which concerns on 1st Embodiment of this invention. It is a figure which shows the relationship between the induced voltage of a motor, and the phase mode at the time of 120 degree | times energization. It is a figure explaining the example of a drive control method of a coil switching motor which is a starting method of the coil switching motor drive device concerning a 1st embodiment of the present invention, and each waveform example. It is the figure which showed the example of an actual motor current waveform at the time of applying the restarting method demonstrated in FIG. It is a figure which shows the example of a characteristic of an air conditioner and a compressor when the coil | winding switching motor drive device which concerns on 1st Embodiment of this invention is applied as a compressor drive device of an air conditioner. It is a figure which shows the structural example of an air conditioner. It is a figure which shows the example of the total efficiency of a motor and an inverter with respect to rotational speed when the coil | winding switching motor drive device which concerns on 1st Embodiment of this invention is applied as a compressor drive device of an air conditioner. It is a schematic diagram which shows the outline | summary of the rotational speed-torque characteristic of a motor when the coil | winding switching motor drive device which concerns on 1st Embodiment of this invention is applied as a compressor drive device of an air conditioner. It is a figure which shows the structural example of the motor drive circuit of the coil | winding switching motor drive device which concerns on 2nd Embodiment of this invention. It is a figure which shows the structure and state which the coil | winding of the motor which concerns on 2nd Embodiment of this invention switches, (a) is each phase connecting each 3 coil | windings in series, and making it Y connection, (B) is a Y connection with one winding for each phase, and three Y connections are connected in parallel. It is a figure which shows the example of the starting method at the time of starting in 2nd Embodiment of this invention, and a waveform example. It is a figure which shows the example of the total efficiency of a motor and an inverter with respect to the rotational speed in 2nd Embodiment of this invention. It is a schematic diagram which shows the outline | summary of the rotational speed-torque characteristic of the motor in 2nd Embodiment of this invention. It is a figure which shows the example of a structure of the coil | winding switching motor drive device which concerns on 3rd Embodiment of this invention, the whole structure of a motor, and a compressor, and a relationship. It is a figure which shows the drive method of the motor of a 120 degree | times electricity supply system, a motor induced voltage, and the relationship of a motor current. It is a figure which shows the relationship of the drive method of a 180 degree energization system motor, a motor induced voltage, and a motor current. It is a figure which shows the computing equation corresponding to the electricity supply system and winding state in the coil | winding switching motor drive device which concerns on 1st Embodiment of this invention. It is a figure explaining the three-step series-parallel winding switching method in U phase as other embodiment of this invention, (a) is U1-U4 winding connected in series, (b) is U1, U2 and U3, U4 are respectively connected in parallel, and (c) shows that all the windings of U1 to U4 are connected in parallel. It is a figure explaining the starting method of a comparative example. It is a figure which shows the relationship between the capability of an air conditioning machine at the time of using a comparative example, the discharge pressure of a compressor, and suction pressure.

  Hereinafter, modes for carrying out the invention of the present application (hereinafter referred to as “embodiments”) will be described with reference to the drawings.

(First embodiment: winding switching motor driving device)
A winding switching motor driving apparatus (100) according to a first embodiment of the present invention will be described with reference to FIGS. It also serves as a description of the drive control method for the winding switching motor.

As will be described later, the windings of each phase of the motor 3 (FIG. 1) are switched in series and in parallel by the winding switching circuit 2 (FIG. 1) of the winding switching motor driving device 100 (FIG. 1).
Incidentally, in the case of a low rotational speed (number of revolutions per unit time), in each phase of the motor 3 (FIG. 1), the connection of two windings is connected in series (U1, U2 in the U phase: FIG. 4). (A)).
Further, in the case of a high rotational speed, the connections of the two windings are arranged in parallel in each phase of the motor 3 ((b) in FIG. 4).
The reason for this is that when the rotational speed is low, the induced voltage (counterelectromotive force) in the winding is small, so that a higher voltage is applied and the motor efficiency is better when the windings are connected in series. On the other hand, in the case of a high rotational speed, the induced voltage in the winding increases, so that the motor efficiency is better when the windings are connected in parallel in order to reduce the influence.
In addition, when switching the connection of the winding from the series connection to the parallel connection, it is desirable that the induced voltage in the winding is in a saturated state exceeding the terminal voltage of the winding.
Further, when switching the winding of the motor 3 from serial to parallel, the motor 3 is temporarily stopped.

≪Configuration of winding switching motor drive system≫
Hereinafter, a specific configuration, operation, and processing of the winding switching motor driving device will be described.
FIG. 1 shows a configuration example of a winding switching motor driving apparatus 100 according to the first embodiment of the present invention, a motor (permanent magnet synchronous motor) 3 that is controlled by the winding switching motor driving apparatus 100, and the motor 3. It is a figure which shows the whole structure and relationship of the compressor 5 which drive.
In FIG. 1, a winding switching motor driving apparatus 100 includes a motor driving circuit 1, a winding switching circuit 2 for switching the windings of the motor 3 in series connection and parallel connection, and a control circuit 4 for controlling the whole. Configured.
First, the details of the configuration of the winding switching motor driving apparatus 100 will be described.

<Motor drive circuit 1>
FIG. 2 is a diagram illustrating a configuration example of the motor drive circuit 1.
As shown in FIG. 2, the motor drive circuit 1 includes a rectifier circuit 10 that converts an alternating current power source (not shown) into direct current, a smoothing circuit 11 that includes a capacitor, and an inverter circuit that drives the motor 3 (FIG. 1). 12.
That is, the AC power (voltage) of the AC power supply is converted into DC power (voltage) by the rectifier circuit 10, and the DC voltage (power) is smoothed and stabilized by the smoothing circuit 11. Is converted into three-phase (U-phase, V-phase, W-phase) AC power (voltage) of variable frequency by the inverter circuit 12.
The inverter circuit 12 receives a drive signal 4C for driving each element of the inverter by the control circuit 4 (FIG. 1), and operates under the control of this signal.

The motor drive circuit 1 further includes a terminal voltage detection circuit 14 that detects a terminal voltage of each phase of the motor 3, a current detection circuit 13 that detects a direct current flowing into the inverter circuit 12, and a smoothing circuit 11. And a DC voltage detection circuit 15 for detecting a DC voltage at both ends.
Here, the terminal voltage detection circuit 14 is configured by a voltage dividing resistor by a plurality of resistors 14R, and detects the terminal voltage of each phase of the U phase, V phase, and W phase, which is the three-phase output of the inverter circuit 12, The terminal voltage detection value 4D is output to the control circuit 4.
Although not shown in detail, the DC voltage detection circuit 15 is composed of a voltage dividing resistor as in the case of the terminal voltage detection circuit 14 described above, and controls a DC voltage detection value 4A that is a DC voltage across the smoothing circuit 11. It is output to the circuit 4.
The current detection circuit 13 detects a direct current flowing into the inverter circuit 12 and outputs a direct current detection value 4 </ b> B to the control circuit 4.

<Winding switching circuit 2>
Next, the winding switching circuit 2 will be described with reference to FIGS.
FIG. 3 shows an example of the internal configuration of the winding switching circuit 2, the connection relationship between the U-phase, V-phase, and W-phase windings of the motor 3 (FIG. 1), and the connection of the motor drive circuit 1 (FIG. 1). It is a figure which shows the connection relationship with the terminals U, V, and W.
FIG. 4 is a diagram showing a state in which the motor windings are switched by the winding switching circuit 2. FIG. 4A shows a state in which the windings of each phase are connected in series, and FIG. It is a figure which shows the state which each coil | winding of became parallel.

In FIG. 3, the switches 21, 22, 23, and 24 operate according to the winding switching signal 4 </ b> E from the control circuit 4.
The switches 21, 22, 23 are connected to the “parallel” side of the switches 21, 22, 23 in FIG. When the signal indicates series, it is connected to the “series” side of the switches 21, 22, and 23.
The switch 24 is connected together when the winding switching signal 4E is a signal for instructing parallelism, and is not connected when the signal for instructing series is used.

A terminal on the fixed side of the contact of the switch 21 (terminal on the left side in the drawing, hereinafter referred to as “fixed side terminal” terminal) is connected to the first terminal (first terminal) of the winding U2.
In addition, the movable side parallel side terminal of the two contacts of the switch 21 (the terminal indicated as “parallel” on the right side in the drawing, hereinafter referred to as “movable parallel side terminal”) is the first terminal (2 of the winding U1). The terminal on the movable side in series with the two contacts (terminal indicated as “series” on the right side in the drawing, hereinafter referred to as “movable series terminal”) is the second terminal of the winding U1. (No. 3 terminal) is connected.

The fixed terminal of the switch 22 is connected to the first terminal (fourth terminal) of the winding V2.
Further, the movable parallel side terminal of the switch 22 is connected to the first terminal (No. 5 terminal) of the winding V1, and the movable series side terminal is connected to the second terminal (No. 6 terminal) of the winding V1. .

The fixed terminal of the switch 23 is connected to the first terminal (7th terminal) of the winding W2.
The movable parallel terminal of the switch 23 is connected to the first terminal (8th terminal) of the winding W1, and the movable series terminal is connected to the second terminal (9th terminal) of the winding W1. .

The two contact fixed side terminals of the switch 24 are connected to the second terminal (No. 9 terminal) of the winding W <b> 1 and the movable series side terminal of the switch 23.
Further, the two contact movable parallel terminals of the switch 24 are connected to the second terminal (No. 6 terminal) of the winding W <b> 1 and the movable series terminal of the switch 22.
Further, the two contact movable series side terminals of the switch 24 are connected to the second terminal (third terminal) of the winding U1 and the movable series side terminal of the switch 21.

The connection terminal U of the motor drive circuit 1 (FIG. 1) is connected to the first terminal (second terminal) of the winding U1 and the movable parallel terminal of the switch 21.
The connection terminal V of the motor drive circuit 1 is connected to the first terminal (No. 5 terminal) of the winding V <b> 1 and the movable parallel terminal of the switch 22.
The connection terminal W of the motor drive circuit 1 is connected to the first terminal (8th terminal) of the winding W1 and the movable parallel terminal of the switch 23.

  The second terminals of the winding U2, winding V2, and winding W2 of the motor 3 are connected to each other.

With the above configuration, when the winding switching signal 4E from the control circuit 4 issues a “series” command, the switches 21, 22, 23 and the switch 24 of the winding switching circuit 2 are positioned on the series side.
At this time, as shown in FIG. 4A, the windings U1 and U2, the windings V1 and V2, and the windings W1 and W2 of the motor 3 are connected in series, and the connection terminals U and A Y connection is formed between V and W (series connection “1Y”).

Further, when the winding switching signal 4E from the control circuit 4 gives a command "parallel", the switches 21, 22, 23 and the switch 24 of the winding switching circuit 2 are positioned on the parallel side.
At this time, as shown in FIG. 4B, the winding U1, the winding V1, and the winding W1 of the motor 3 are Y-connected to the connection terminals U, V, and W of the motor driving circuit 1. The
Further, the winding U2, the winding V2, and the winding W2 of the motor 3 are configured with a Y connection between the connection terminals U, V, and W of the motor driving circuit 1.
That is, the Y connection by the windings U1, V1, and W1 and the Y connection by the windings U2, V2, and W2 are configured in parallel with the two Y connections between the connection terminals U, V, and W (in parallel). Connection “2Y”).

The motor 3 having the windings U1, U2, V1, V2, W1, and W2 and the winding switching circuit 2 are connected by nine wires. In FIGS. 1 and 3, these nine wires are connected. Is denoted by reference numeral 2A.
In FIG. 3, switches 21 to 24 are represented as mechanical switches (mechanical contacts, opening and closing are controlled by electric signals), but semiconductor switches may be used.

<Processing of control circuit 4: Part 1>
FIG. 5 is a block diagram showing a configuration example of processing of the control circuit 4 of the first embodiment. In order to understand why the processing shown in FIG. 5 is performed, first, the first embodiment of the present invention is used. The form activation method and the related technology will be described first.
Thereafter, a detailed method and technique of the first embodiment such as a processing block diagram of the control circuit 4 of FIG. 5 will be described.

≪Starting method of the present invention≫
Next, the starting method of the present invention will be described with reference to FIG.
FIG. 11 is a diagram illustrating an example of a drive control method for a winding switching motor, which is a starting method for the winding switching motor driving device according to the present invention. 6 to 10 will be described later as in FIG.
In FIG. 11, the horizontal axis represents the history of time, and the vertical axis represents the items of rotation speed command, current command (Id ^* ), current command (Iq ^* ), motor current (Iu), and energization method switching signal. Have been described.
The current command (Id ^* ) is an excitation current command, and the current command (Iq ^* ) is a torque current command. Further, since it is a synchronous motor, the central axis of the field magnetic pole (permanent magnet) is d-axis and the direction perpendicular to it is q-axis.
In addition, the energization method switching signal selects and switches between two types of energization methods: 120-degree energization (120-degree energization method) and 180-degree energization (180-degree energization method).
Details of the 120-degree energization method and the 180-degree energization method will be described later.

<Before time T1>
Prior to time (time) T1, the motor is stopped in order to change the rotational speed of the motor 3 (FIG. 1). In addition, before stopping the motor 3, it shall operate | move by 180 degree | times energization (180 degree energization system).

<< Section of time T1-T2 >>
In order to restart the motor 3 properly, the motor (rotor) is positioned during the time T1 to T2 (section). This positioning is performed by issuing a current command (Id ^* ) which is an excitation current command.
When starting at time T1, the initial setting current value calculated during driving is set as the final value of the current command (Id ^* ) that is the excitation current command, and the current value is gradually increased (characteristics) Line 111).
Note that the characteristic line 111 indicates that the current command (Id ^* ) rises at time T1 to T2. Further, the motor current (Iu) is also increased by the current command (Id ^* ) (characteristic line 112).

<< Interval from time T2 to T3 >>
At time T2, the positioning process is completed, and the mode is switched to the 120-degree energization method (120-degree energization) that allows easy variable speed control.
At the time of switching, similarly to the above, the initial setting current value at the time of 120-degree energization calculated during driving is set in the torque current command (Iq ^* ).
Since acceleration occurs during the period from time T2 to time T3, the motor current value of 120-degree energization increases as the torque current command (Iq ^* ) increases by the speed control process described later (characteristic line 114).
The characteristic line 114 shows how the torque current command (current command Iq ^* ) gradually increases.
Further, the rotational speed command is a command for increasing the rotational speed of the motor in the section of time T2-T3 (characteristic line 113).

A characteristic line 115 indicates a current waveform of the motor current (Iu) in the T2-T3 section.
In the 120-degree energization method (120-degree energization), the drive waveform (drive signal) has a rectangular wave shape (FIG. 23), as will be described later. Therefore, also in FIG. 11, the motor current (Iu) is close to a rectangular wave. It is a waveform (characteristic line 115).
Further, as described above, since the rotational speed command (characteristic line 113) rises and the current command (Iq ^* ) also rises, the current waveform of the motor current (Iu) becomes a current wave while the oscillation period becomes faster. The high value is also rising (characteristic line 115).

<< Interval from time T3 to T4 >>
Thereafter, when the motor rotational speed reaches a rotational speed at which 180-degree energization control is possible, the energization method is switched from 120-degree energization to 180-degree energization with a small torque fluctuation at time T3.
At this time, the motor current value at the time of 120-degree energization immediately before switching and the initial setting current value at the time of 180-degree energization calculated from the winding specifications are set in the torque current command (Iq ^* ) (value at T3 of the characteristic line 116) ).
Since the section from time T3 to T4 is also accelerating, the torque current command (Iq ^* ) is increased by the speed control process, and the motor current (Iu) increases the frequency of vibration and the peak value of the current. (Characteristic line 117).

<After time T4>
When the acceleration is completed at time T4, a predetermined current value corresponding to the state of the compressor load and the rotational speed is settled.
That is, the torque current command (Iq ^* ) is a characteristic line 118, and the motor current (Iu) is a current waveform having a frequency and a peak value indicated by the characteristic line 119.

  By performing the above processing, the compressor can be restarted stably and in a short time even when the differential pressure after switching the windings is maintained.

As described above, this activation method adopts the 120-degree energization method without performing the conventional synchronous operation processing (see the comparative example described later, FIG. 27) after the positioning processing.
Then, at a predetermined rotational speed or higher, the 120-degree energization method is switched to 180-degree energization (vector control).
Here, the 180 degree energization method is used because the torque fluctuation of the motor can be reduced compared to the 120 degree energization method, and field weakening control in the high speed region (excitation current is made to flow negatively at the time of voltage saturation to make the field This is because control to weaken the image is possible.
In addition, as shown in FIG. 11, other features of the present invention include a current value (characteristic line 111) at the time of positioning processing and an initial current value (characteristic line 116 at T3 when switching from the 120-degree energization method to the 180-degree energization method). Current value) is variable.

Another object of the present invention is to immediately and stably restart the motor while temporarily switching the winding and maintaining the differential pressure.
Therefore, the motor torque (load torque) immediately before the stop is calculated from the motor current value immediately before the motor stop, the winding state, and the energization method, the motor current value after the coil switching is calculated from this torque, and the value is positioned. The current value is set. By doing so, the necessary torque current is ensured, so that the motor torque is not excessive or insufficient, and stable start-up is possible.
Also, when switching between 120-degree energization and 180-degree energization, the value of the generated torque differs even with the same motor current due to the difference in energization method, so the motor current should be set by compensating for the difference in output torque for the difference in energization method. Thus, torque fluctuation at the time of switching can be minimized, and stable starting can be ensured.

<Actual motor current waveform>
FIG. 12 is a diagram illustrating an example of an actual motor current waveform when the restart method described in FIG. 11 is applied.
In FIG. 12, the horizontal axis is the time course and the vertical axis is the current value. Further, the meanings of “positioning”, “120-degree energization”, and “180-degree energization” correspond to FIG. 11, and “stopped” corresponds to the state before T1 in FIG.
Further, “in acceleration” corresponds to the state of the section from T2 to T4 in FIG.
FIG. 12 is a waveform when restarting with a rotational speed command of 1800 [rpm] in a state of a load torque of 6 [Nm].
It can be seen that it takes about 1 s from the start (positioning) until the rotational speed becomes stable, and there is no significant disturbance of the motor current during that time.

<Characteristics of air conditioner and compressor>
FIG. 13 is a diagram illustrating an example of characteristics of an air conditioner and a compressor when the winding switching motor drive device of the first embodiment is applied as a compressor drive device of an air conditioner.
In FIG. 13, the horizontal axis represents the course of time, and the vertical axis represents the capacity of the air conditioner, the discharge pressure of the compressor, and the suction pressure.
Since the winding switching motor driving device according to the first embodiment of the present invention can freely switch without any restriction on the timing of switching the winding, the stop time (compressor stop time 131) after switching the winding is described later. Compared to the comparative example (FIG. 28, compressor stop time 281), it can be made very small.
In addition, the compressor 134 is compared with the comparative example (FIG. 28, ability 284, discharge pressure 283, suction pressure 282) described later also with respect to the air conditioner capacity 134, compressor discharge pressure 133, and suction pressure 132 during the compressor stop time 131. A decrease (fluctuation) in the stop time 131 can be suppressed very small.

≪About 120 degree conduction method and 180 degree conduction method≫
Here, the operation principle, effects, and features of the 120-degree energization method and the 180-degree energization method will be briefly described.

<120 degree energization method>
First, the 120-degree energization method will be described.
FIG. 23 is a diagram illustrating a relationship between a 120-degree energization motor driving method, a motor induced voltage, and a motor current. 14 to 22 will be described later.
In FIG. 23, the horizontal axis represents an electrical angle (or time course). Also, on the vertical axis, the induced voltage (induced voltage) of the motor, the magnet position detection signal of the rotor (position detection signal) detected from the motor terminal voltage, the drive signal (drive signal) that is the drive signal of the inverter switching element, the motor The motor current (motor current) is shown.

The motor terminal voltage is obtained from a terminal voltage detection value 4D which is a detection signal of the terminal voltage detection circuit 14 (FIG. 2).
Drive signals U, V, and W correspond to control signals for the switching elements of the upper and lower arms that generate the output signal of the inverter circuit 12 (FIG. 2) corresponding to each phase winding of the motor. Indicates an upper arm element, and − indicates a lower arm element.
The position detection signal is a signal that changes at a point where the induced voltage of each phase of the motor-induced voltage becomes the isotope voltage (intersection point).
Also, as shown in FIG. 23, when the energization elements of the switching elements of the inverter are sequentially switched at the point where the position detection signal changes, the period of energization in one phase (either U phase, V phase, or W phase) The electric angle is 120 degrees, and the motor current is a substantially rectangular wave current.

As described above, the 120-degree energization method can easily drive the permanent magnet synchronous motor by creating a position detection signal based on the motor terminal voltage and sequentially switching the energization elements of the inverter according to the position detection signal.
In other words, the constant of the permanent magnet synchronous motor is not required unlike 180 degree energization (vector control) to be described later, so that the variable speed control of the permanent magnet synchronous motor can be easily performed.
However, as shown in FIG. 23, since the motor current has a rectangular wave shape, torque fluctuation due to fluctuation of the motor current occurs at the timing when the switching element of the inverter is switched.
In the above description, the position detection signal is generated from the terminal voltage of the motor. However, in a system in which a magnetic pole position sensor using a Hall element or the like is attached to the motor, the position detection signal is output using the magnetic pole position sensor. You may create it.

<180 degree conduction method>
Next, the 180 degree energization method will be described.
FIG. 24 is a diagram illustrating a relationship between a 180-degree energization motor driving method, a motor induced voltage, and a motor current.
In FIG. 24, the horizontal axis represents the electrical angle (or time course). Also, on the vertical axis, the induced voltage of the motor (induced voltage), the phase signal (phase signal) obtained by estimating the magnet position of the rotor from the motor current by vector calculation, and the drive signal (drive signal) that is the drive signal of the switching element of the inverter The motor current of the motor (motor current) is shown.

The phase signal indicates the rotational phase of the dq coordinate system with reference to the position of the U-phase winding, and is estimated by a 180-degree energization speed / position estimation process 404 in FIG.
Specifically, from the detected motor current value (dq coordinate system) and the motor applied voltage (dq coordinate system), the control axis and the real axis (motor axis) are expressed using the following equation (1). The axis error, which is the error of, is directly calculated. Then, the speed of the control axis is adjusted so that the axis error becomes zero.
The phase signal is created by integrating the adjusted speed.
Further, since the position estimation period is calculated at a high speed such as a 500 μs period, the phase signal changes substantially linearly.

ここで、Δθd：軸誤差演算値、Ｖｄ^*：ｄ軸モータ印加電圧指令値、
Ｖｑ^*：ｑ軸モータ印加電圧指令値、Ｒ：巻線抵抗、
Ｌｄ：ｄ軸インダクタンス、Ｌｑ：ｑ軸インダクタンス
ω^＊：電気角周波数指令、Ｉｄ：ｄ軸モータ電流検出値、
Ｉｑ：ｑ軸モータ電流検出値

Where Δθd: axis error calculation value, Vd ^* : d-axis motor applied voltage command value,
Vq ^* : q-axis motor applied voltage command value, R: winding resistance,
Ld: d-axis inductance, Lq: q-axis inductance
ω ^* : electrical angular frequency command, Id: d-axis motor current detection value,
Iq: q-axis motor current detection value

Further, since the drive signals (U +, U−, V +, V−, W +, W−) are controlled by PWM (Pulse Width Modulation) so that the motor current becomes a sine wave, they are finely divided as shown in FIG. Signal sequence (signal).
As described above, the motor current has a sinusoidal waveform due to the finely divided driving so that the sine wave is reproduced and the large winding (coil) inductance of the motor.
As described above, the 180-degree energization can control the motor current as a sine wave, so the motor output torque is almost constant and the torque fluctuation is small.
In addition, since the phase difference between the induced voltage and the motor current can be freely controlled, maximum control of the torque / current ratio and field-weakening control can be easily performed.
However, in order to perform vector calculations, it is necessary to know the motor constants of the permanent magnet synchronous motor, and a microcomputer capable of performing vector calculations at high speed (referred to as “microcomputer” as appropriate) is also required. Become. Therefore, the control circuit is more expensive than the 120-degree energization method.

<Relationship between induced voltage of motor and phase mode at 120 degrees energization>
Next, the relationship between the induced voltage of the motor and the phase mode at 120 degrees energization will be described.
FIG. 10 is a diagram showing the relationship between the induced voltage of the motor and the phase mode at 120 degrees energization.
As shown in FIG. 10, in the 120-degree energization, the phase mode (1 to 6) is set for each electrical angle of 60 degrees, and the energization phase of the inverter element is determined according to the phase mode.
In FIG. 10, since the energization method is set to be switched in the phase mode (mode) 1, the switching is executed when the phase signal of the induced voltage is from 240 degrees to 300 degrees.
By executing the above processing, the energization method can be switched.

Here, a supplementary explanation will be given regarding the matters related to the phase mode.
As shown in FIG. 10, the phase mode is a mode (1 to 6) in which the phase of the induced voltage is arbitrarily set by dividing the phase of the induced voltage every 60 degrees.
In other words, as shown in FIG. 23, in the 120-degree energization method, the position of the rotor is known only at every electrical angle of 60 degrees (the detailed position below the electrical angle of 60 degrees is unknown), so the electrical angle is 60 degrees. Is set to specify the position of the rotor.
For example, in FIG. 10, the phase mode (mode) 3 shows a range of the induced voltage phase from 330 degrees to 30 degrees, and the energized state between them is as shown in FIG. ) And the W-phase lower arm element (W−) is turned on, and the on / off state of the switching element of the inverter is uniquely determined in the phase mode.

<Processing of control circuit 4: Part 2>
Since the start-up method of the first embodiment of the present invention behind the configuration of the control circuit 4 and related technologies and matters, and the 120-degree energization method and the 180-degree energization method have been described, the description of the control circuit 4 Return to.
FIG. 5 is a block diagram showing a configuration example of processing of the control circuit 4 as described above.
The block diagram of FIG. 5 mainly describes portions relating to motor driving (portions relating to control of the entire system are omitted).
The control circuit 4 uses a microcomputer to realize all processing by software.

The Iq ^* setting process 401 is a rotation speed command N ^* , an operation state signal, a winding switching signal, an energization method switching signal 400A to be described later, a rotation speed N, and a dq conversion of motor current. Excitation current Id and torque current Iq, which are values, are input as signals.
Based on these signals, current command values Iq ^* and Id ^* initial values are calculated. Details will be described later.
In FIG. 5, the "Iq ^* setting process" notation in the block, as "Iq ^* Setting", is omitted for simplicity the word "treatment".
In the following, the description of each block 401 to 412 in FIG. 5 is expressed by omitting the word “processing” from the wording of the explanation.

The Id ^* setting process 412 calculates a current command Id ^* based on the operation state signal, the energization method switching signal 400A, and the Id ^* initial value. Details will be described later.

The current control process 402 sets the second current command value (Id ^** , Iq ^** ) so that the difference between the current command value (Id ^* , Iq ^* ) and the current detection value (Id, Iq) becomes zero. Calculate.
Specifically, the second current command values (Id ^** , Iq ^** ) are calculated using proportional integral control based on each current deviation.

The vector calculation process 403 receives the second current command value (Id ^** , Iq ^** ), the rotation speed N ₁₈₀ and the rotation phase θ ₁₈₀ of the motor 3 to be described later.
The vector calculation processing 403 is based on the second current command value (Id ^** , Iq ^** ) and the set motor constants (R, Ld, Lq, Ke). Is used to calculate motor applied voltages (Vd ^* , Vq ^* ) at 180 degrees energization.

ここで、
Ｋｅ：発電定数

here,
Ke: Power generation constant

  In this vector calculation processing 403, there are two types of motor constants, a series winding constant and a parallel winding constant, and the motor constant is changed in synchronization with the winding switching signal.

The voltage calculation process 406 calculates a voltage command value V ₁₂₀ ^* at 120 degrees energization based on the current command value Iq ^* .

The voltage command selection / pattern generation processing 407 selects either the motor applied voltage (Vd ^* , Vq ^* ) or the voltage command value V ₁₂₀ ^* according to the energization method switching signal 400A, and the voltage corresponding to the energization method. A pattern (180 degree energization is a sine wave, 120 degrees energization is a rectangular wave) is output.
The voltage command selection / pattern generation processing 407 also receives a DC voltage detection value 4A that is a DC voltage across the smoothing circuit 11 (FIG. 2).

  The PWM signal output processing 408 converts the voltage pattern output from the voltage command selection / pattern generation processing 407 into a PWM pulse signal (drive signal) 4C and outputs the PWM pulse signal (drive signal) 4C to the inverter circuit 12.

The 120-degree energization speed / position estimation process 405 calculates the rotation speed N ₁₂₀ and the rotation phase θ ₁₂₀ of the motor 3 based on the terminal voltage detection value 4D.

  The current reproduction process 411 reproduces the motor current detection values (Id, Iq) from the switch timing of the DC current detection value 4B and the PWM pulse signal (drive signal) 4C.

The 180-degree energization speed / position estimation process 404 uses the current detection values (Id, Iq) and the motor applied voltages (Vd ^* , Vq ^* ) to rotate the motor 3 at a rotational speed N ₁₈₀ and a rotational phase θ _180. Is calculated.

The speed selection process 410 selects either the rotation speed N ₁₈₀ or the rotation speed N ₁₂₀ based on the energization method switching signal 400A and outputs it as the rotation speed N.
Specifically, when the energization method is 120-degree energization, the rotational speed N ₁₂₀ is selected, and when the energization method is 180-degree energization, the rotational speed N ₁₈₀ is selected.

The energization method switching determination processing 409 outputs an energization method switching signal 400A using the operation state signal, the rotation speed N, the rotation phase θ ₁₈₀ , and the rotation phase θ ₁₂₀ . Details will be described later.

≪Iq ^* setting process, Id ^* setting process, energization method switching determination process≫
Next, Iq ^* setting processing 401, Id ^* setting processing 412, and energization method switching determination processing 409, which are main parts of the present invention, will be described in detail.

FIG. 6 shows an internal configuration of the Iq ^* setting process 401, and FIG. 7 shows a flowchart of the Iq ^* setting process 401. These will be described in order.

<Block Diagram of Iq ^* Setting Process 401>
FIG. 6 is a block diagram illustrating a configuration example of processing inside the Iq ^* setting processing 401.
The Iq ^* setting process 401 includes a speed control process 401A, an initial value selection process 401B, a 120 degree initial value process 401C, and a 180 degree initial value process 401D.
Here, the speed control process 401A calculates the torque current command Iq ^* from the deviation between the rotational speed command N ^* and the rotational speed N from the host process. The speed control process 401A has an integral (integral term) in the calculation process.
In addition, the initial value selection processing 401B uses the energization method switching signal 400A, the operation state signal, and the winding switching signal (for understanding the winding state) to integrate the Iq ^* setting processing 401 and the Id ^* setting processing 412. Select the term initial value.
The 120 degree initial value process 401C calculates the initial value of 120 degree energization selected in the initial value selection process 401B.
The 180 degree initial value process 401D calculates the initial value of 180 degree energization selected in the initial value selection process 401B.

<Flowchart of Iq ^* setting process 401>
FIG. 7 is a flowchart illustrating an operation example of the Iq ^* setting process 401.
The operation of the Iq ^* setting process 401 will be described using the flowchart of FIG.

<< Steps S100 and S101 >>
In FIG. 7, step S100 indicated by “1” in a circle is the start state.
First, in step S101, the driving state is determined using the driving state signal (what is the exercise state?).
If it is “stopping and positioning”, the process proceeds to step S102.
If it is “driving”, the process proceeds to step S105.

<< Step 102 >>
In step 102, it is confirmed whether positioning is completed (positioning complete?).
If it is stopped or positioning (“stopping / positioning”), the process proceeds to step S103.
If the positioning is complete (“positioning complete”), the process proceeds to step S104.

<Step 103>
In step S103, 0 is set to the torque current command Iq ^* .
Then, the process proceeds to the step “1” indicated by a circle. That is, the process returns to the start state of step S100.

<< Step 104 >>
In step 104, the torque current command Iq ^* and the integral term of the speed control process 401A are set to the Iq ^* 120 degree initial value calculated in the 120 degree initial value process 401C.
Then, the process proceeds to the step “1” indicated by a circle. That is, the process returns to the start state of step S100.

<Step 105>
If “in driving” in step S101 described above, the process proceeds to step S105.
In step S105, the energization method is confirmed based on the energization method switching signal 400A (180-degree energization?).
If “120 degrees energized”, the process proceeds to step S106. On the other hand, in the case of “180 ° energization”, the process proceeds to step S108.

<Step 106>
In step 106, the Iq ^* 180 degree initial value is calculated and held in the 180 degree initial value process 401D. Then, the process proceeds to step S107.

<< Step 107 >>
In step 107, the energization method switching signal 400A is confirmed to determine whether or not the energization method is switched (180-degree energization switching?).
In the case of “180 degree switching”, that is, if there is a request for switching to 180 degree energization, the process proceeds to step S110.
If there is no request for switching to 180-degree energization, the process proceeds to step 111.

<< Step 110 >>
In step 110, the integral term of the torque current command Iq ^* and the speed control processing 401A described above, sets the ^Iq * 180 initial value calculated by the 180 degree initial value processing 401D (Iq ^* and the above-mentioned speed control Iq ^* 180 degree initial value is set in the integral term).

<Step 111>
In step 111, as described above, the torque control command Iq ^* is calculated in the speed control process 401A (speed control).

<Step 108>
In step S105 described above, if “180 degrees energized”, the process proceeds to step S108.
In step S108, the Iq ^* 120 degree initial value in the 120 degree initial value processing 401C described above is calculated and held.
Then, the process proceeds to step S109.

<< Step S109 >>
In step S109, the energization method switching signal 400A is confirmed to determine whether or not the energization method is switched (120-degree energization switching?).
If there is a request for switching to 120-degree energization (when switching to 120 degrees), the process proceeds to step S112.
If there is no switching request (No), the process proceeds to step S111.

<< Step S111: Repost >>
Since step S111 has been described above, a duplicate description is omitted.

<< Step S112 >>
In step S112, it sets the ^Iq * 120 degrees initial value is calculated by the 120-degree initial value processing 401C to the integral term of the torque current command Iq ^* and the speed control processing 401A.

By performing the above steps S101 to S112, the Iq ^* 120 degree initial value and the Iq ^* 180 degree initial energization value are calculated and maintained, while the speed control process and the restart after the stable coil switching and the energization method are performed. Switching processing is possible.
Further, by the process and operation of the Iq ^* setting process 401 described above, the initial value of the motor current after the coil switching is set to be equal to or greater than the motor current value calculated from the motor current value before the stop and the connection state of the winding. Is set.
Further, since the torque current command (Iq ^* ) is made by the Iq ^* setting process 401, the torque after the winding switching is ensured to be equal to or higher than the torque before the stop for the torque of the motor 3 (FIG. 1).

<Calculation method of initial current set value (120-degree conduction, 180-degree conduction)>
Here, a method for calculating the above-described initial current setting values (120-degree energization, 180-degree energization) will be described.
FIG. 25 is a diagram illustrating an example of an arithmetic expression corresponding to the energization method and the winding state. 8 to 10 will be described later.
In FIG. 25, items “180-degree energization → 120-degree energization”, “120-degree → 180-degree energization”, “180-degree energization”, and “120-degree energization” are entered from the top to the bottom in the leftmost column. ing.
These items mean whether the energization method is switched or continued at the time of restart in FIG.
That is, “180 degree energization → 120 degree energization” means switching from the 180 degree energization method to the 120 degree energization method.
Further, “120 ° → 180 ° energization” means switching from the 120 ° energization method to the 180 ° energization method.
“180 degree energization” means that the 180 degree energization method is continued.
Further, “120 degree energization” means that the 120 degree energization method is continued.

In FIG. 25, in the upper column, items “parallel connection → series connection”, “series connection → parallel connection”, “parallel connection”, and “series connection” are described from left to right.
These items mean whether to switch or continue the connection of the motor windings before T1 in FIG. 11, “during stop” in FIG. 12, or compressor stop time 131 in FIG. 13.
That is, “parallel connection → series connection” means switching from the connection shown in FIG. 4B to the connection shown in FIG.
Further, “series connection → parallel connection” means switching from the connection shown in FIG. 4A to the connection shown in FIG.
“Parallel connection” means that the connection shown in FIG. 4B is continued.
Further, “series connection” means that the connection shown in FIG. 4A is continued.

As described above, the initial current setting is made by various combinations of switching the energization method or continuing at the time of restart, and switching or continuing the connection of the motor winding when the motor is stopped. Values (120 degree energization, 180 degree energization) are different.
FIG. 25 is a list of arithmetic expressions for calculating initial current setting values (120-degree energization, 180-degree energization) for the above combinations.
In the arithmetic expressions in the respective columns in FIG. 25, “Ia” means the initial current set value, and the subscript “120” or “180” means 120 degree energization and 180 degree energization, respectively. The subscript “s” or “p” means series or parallel, respectively.

In the first embodiment of the present invention, the initial current set value according to each situation is calculated in advance using the arithmetic expression shown in FIG.
Here, equations that are the basis of the arithmetic expression shown in FIG. 25 are shown as equations (3) and (4) below.
The arithmetic expression shown in FIG. 25 is a relational expression obtained by using equations (3) and (4) and obtaining a current value at which the output torque is constant under each condition.

Here, for example, when the motor windings are energized 180 degrees in parallel connection and the motor windings are switched to series connection and restarted at 120 degrees energization when restarting after stopping, The formula of (A) of FIG. 25 is used.
Further, when the motor windings are energized 180 degrees in series connection before the stop, and the motor windings are switched to the parallel connection and restarted after being stopped, the motor windings are driven with 180 degrees energization as shown in FIG. (B) is used.
As described above, the calculation formula is selected based on the connection state of the windings and the energization method before the stop and at the restart after the stop.

ここで、
Ｔ１８０：１８０度通電の出力トルク
Ｔ１２０：１２０度通電の出力トルク
Ｋｔａ：１相あたりのトルク定数、
Ｉａ１８０：１８０度通電時のモータ相電流波高値
Ｉａ１２０：１２０度通電時のモータ相電流波高値

here,
T180: Output torque of 180 degree energization
T120: Output torque of 120 degree energization
Kta: torque constant per phase,
Ia180: Motor phase current peak value at 180 degrees energization
Ia120: Motor phase current peak value at 120 degrees energization

In FIG. 25, the torque constant is calculated by setting the torque constant at the time of series connection to twice that of the torque constant at the parallel connection.
That is, as shown in FIG. 4, the torque constant has a one-to-two relationship because of switching between parallel connection (1Y) and series connection (2Y).
In addition, the current value is subscripted to distinguish the current in parallel connection from the current in series connection (parallel connection “p”, series connection “s”).
Here, the motor phase current peak value Ia has the relationship of Expression (5). In the present embodiment, since a motor having no saliency is assumed, Id is 0. Therefore, it can be handled as Ia = Iq.

  In this embodiment, the formula (3) is applied as the torque formula, but it is also possible to use the formula (6) which is a torque formula (expressed by relative conversion) in the dq coordinate system.

ここで、τ：モータ出力トルク、Ｐ：極対数

Where τ: motor output torque, P: number of pole pairs

When using a motor with saliency, it is necessary to use an equation (such as equation (6)) that also considers saliency. In other words, the arithmetic expression shown in FIG. 25 changes according to the motor winding specifications and the applied torque arithmetic expression.
In the present embodiment, the acceleration torque is not taken into account for simplification of description, but in a system that requires rapid acceleration, it is also necessary to take into account the acceleration torque.
That is, it is desirable to set the initial current set value calculated in FIG. 25 by adding the current value for the acceleration torque.

<Flowchart and Operation of Id ^* Setting Process 412>
FIG. 8 is a flowchart illustrating an operation example of the Id ^* setting process 412.
Next, the operation of the Id ^* setting process 412 will be described using the flowchart of FIG.

<< Steps S200 and S201 >>
In FIG. 8, step S200 indicated by “2” in a circle is in the start state.
First, an operation state is determined in step S201. If it is stopped or driving (stopping / driving), the process proceeds to step S202, if it is activated (activated), the process proceeds to step S206, and if positioning is being performed, the process proceeds to step 207.

<< Step S202 >>
In step S202, the energization method is confirmed (180-degree energization?).
If it is 120 degrees energization (120 degrees energization), the process proceeds to step S203.
On the other hand, if the current is 180 degrees, the process proceeds to step S204.

<< Step S203 >>
In step S203, the excitation current command (Id ^* ) is set to 0 (Id ^* = 0 set).
Then, the process proceeds to the step “2” indicated by a circle. That is, the process returns to the start state of step S200.

<< Step S204 >>
In step S204 after confirming that 180-degree energization is being performed, it is confirmed whether field-weakening control is being performed (field-weakening control?).
If it is under normal control, the process proceeds to step S203.
If the field is weak, the process proceeds to step S205.

<< Step S203: Repost >>
Since step S203 has been described above, a duplicate description is omitted.

<< Step S205 >>
In step S205, the excitation current command (Id ^* ) is changed by field weakening control.
Then, the process proceeds to the step “2” indicated by a circle. That is, the process returns to the start state of step S200.
The field weakening control method is not particularly specified.

<< Step S206 >>
In step S206, the Id ^* positioning current value (final value) is set to the Iq ^* 120 degree initial value calculated in the Iq ^* setting process 401 (Id ^* positioning current (final value) = Iq ^* 120 degree initial value. set).
Here, the positioning current value may be calculated and set separately, but it is desirable to set the Iq ^* 120 degree initial value in order to match the current value with the 120 degree energization after the positioning process.
Then, the process proceeds to the step “2” indicated by a circle. That is, the process returns to the start state of step S200.

<< Step S207 >>
Step S207 is a process for increasing the positioning current, and the excitation current (Id ^* ) is increased until it reaches the set value (final value) (Id ^* is gradually increased until it reaches the Id ^* final value).
Then, the process proceeds to the step “2” indicated by a circle. That is, the process returns to the start state of step S200.

<Flowchart of energization method switching determination processing 409>
FIG. 9 is a flowchart illustrating an operation example of the energization method switching determination process 409.
Next, the operation of the energization method switching determination process 409 will be described using the flowchart of FIG.

<< Steps S300 and S301 >>
In FIG. 9, step S300 indicated by “3” in a circle is the start state.
First, in step S301, the operating state is confirmed.
If positioning is in progress, the process proceeds to step S302.
If driving, the process proceeds to step S304.
If it is stopped, the process returns to the start state of step S300 indicated by “3” in a circle.

<< Step S302 >>
In step S302, it is confirmed whether positioning has been completed (positioning is completed?).
If the positioning has been completed, the process proceeds to step S303.
If positioning is in progress, the process returns to step S301.
That is, in step S302, it is confirmed whether the positioning is completed, and the processes in steps S301 and S302 are repeated until completion.

<< Step S303 >>
In step S303, the energization method switching signal is set to 1 (120-degree energization).
Then, the process proceeds to the step “3” indicated by a circle. That is, the process returns to the start state of step S300.

<< Step S304 >>
In step S304, the current energization method is confirmed.
In the case of 120-degree energization, the process proceeds to step S305.
In the case of 180 degree energization, the process proceeds to step S308.

<< Step S305 >>
In step S305, the operating rotational speed (the rotational speed per unit time) N is compared with N ₁₂₀ , which is the rotational speed before switching to 180-degree energization (N ≧ N ₁₂₀ ).
If the rotational speed N is equal to or higher than the switching rotational speed (N ₁₂₀ ), the process proceeds to step S306.
If the rotational speed N is less than the switching rotational speed (N ₁₂₀ ), the process proceeds to the step “3” circled. That is, the process returns to the start state of step S300.

<< Step S306 >>
In step S306, it is determined whether or not the 120 ° energization phase signal θ ₁₂₀ is mode 1.
When the 120-degree energization phase signal θ ₁₂₀ is mode 1, the process proceeds to step S307. The process proceeds to step S307 when the 120-degree energization phase signal θ ₁₂₀ becomes mode 1 (FIG. 10). When the 120-degree energization phase signal θ ₁₂₀ is other than mode 1, the circle indicates “3”. Go to step. That is, the process returns to the start state of step S300.

<< Step S307 >>
In step S307, the energization method switching signal is set to 0 (180-degree energization).
Then, the process proceeds to the step “3” indicated by a circle. That is, the process returns to the start state of step S300.

<< Step S308 >>
In step S308, the rotational speed N is compared with N ₁₈₀ which is the rotational speed for switching to 120-degree energization (N ≦ N ₁₈₀ ).
If the rotation speed N is equal to or lower than the switching rotation speed (N ₁₈₀ ), the process proceeds to step S309.
Further, if the rotational speed N is higher than the switching rotational speed (N ₁₈₀ ), the process proceeds to the step “3” in a circle. That is, the process returns to the start state of step S300.

<< Step S309 >>
In step S309, the when the 180-degree energization of the phase signal theta ₁₈₀ is mode 1, the process proceeds to step S310.
In step S309, if the 180 ° energization phase signal θ ₁₈₈₀ is not in mode 1, the process proceeds to step “3” in a circle. That is, the process returns to the start state of step S300.

<< Step S310 >>
In step S310, the energization method switching signal is set to 1 (120-degree energization).
Then, the process proceeds to the step “3” indicated by a circle. That is, the process returns to the start state of step S300.

<Relationship between winding switching operation and effect>
The relationship between the winding switching operation and the effect when the motor driving device described so far is applied to an air conditioner (refrigeration air conditioning equipment) will be described.
FIG. 14 is a diagram illustrating a configuration example of an air conditioner.
In FIG. 14, the air conditioner includes an air conditioner indoor unit (evaporator) 141 and an air conditioner outdoor unit (condenser) 142.
Winding switching motor drive device (motor drive device) 100 (FIG. 1), motor 3 (FIG. 1) driven by this motor drive device, and compressor 5 driven by this motor 3 (FIG. 1) ) Is mounted on the air conditioner outdoor unit (condenser) 142 in FIG.

<Total efficiency of motor and inverter>
Next, the overall efficiency of the motor and inverter will be described.
FIG. 15 is a diagram illustrating an example of the total efficiency of the motor and the inverter with respect to the rotation speed. In addition, the winding state and the capacity of the air conditioner (APF measurement conditions) are also shown.
In FIG. 15, a characteristic line 151 indicates the overall efficiency of a conventional general motor (a motor that does not switch windings).
In addition, the characteristic line 152 is an efficiency using a motor connected in series with a motor (winding switching motor) driven by the winding switching drive device of this embodiment, and the characteristic line 153 is a motor using a parallel connection. Efficiency.

In the case of a motor that does not switch windings (characteristic line 151), since it is necessary to ensure driving in the overload capacity region, the efficiency peak point cannot be set in a very low rotational speed region.
For this reason, the efficiency improvement in the minimum capacity area and the intermediate capacity area having a long operation time is reduced, and the APF cannot be expected to be significantly improved.

On the other hand, the winding switching motor driven by the winding switching drive device of this embodiment can change the peak point of efficiency by switching the winding. For this reason, in the region below the intermediate capacity, the peak value of the switching efficiency is moved to the low rotation side in series connection (characteristic line 152).
On the other hand, when outputting a capacity higher than the rated capacity, the connection is switched to the parallel connection (characteristic line 153) in order to improve the efficiency of the rated capacity and to secure driving in the overload capacity range.

In FIG. 15, the minimum capacity, the intermediate capacity, the rated capacity, and the overload capacity are indicated, but these are predetermined items determined in the APF evaluation test. For example, the rated capacity indicates a range and does not necessarily match the rated value described as a device. Even in the case of an air conditioner, the characteristics near the rated value are different in cooling, ventilation and heating. Therefore, the rated capacity in the evaluation test has a predetermined range as shown in FIG.
The intermediate capacity is set to approximately 50% of the rated capacity. Moreover, the range between the rated capacity and the overload capacity is a range without a special name in the evaluation test.

FIG. 16 is a schematic diagram showing an outline of the rotational speed-torque characteristics of the motor. In addition, it also indicates in which range the capacity range (minimum capacity, intermediate capacity, rated capacity, overload capacity) of the air conditioner is located in the rotational speed-torque characteristics.
In FIG. 16, the characteristic line 171 is conventional (a motor that does not switch windings).
Further, when the characteristic line 172 is connected in series with a motor (winding switching motor) driven by the winding switching drive device of this embodiment, the characteristic line 173 is a motor (winding) driven by the winding switching drive device of this embodiment. It is the characteristic of the motor at the time of the parallel connection of the motor of a line switch.
As can be seen from FIG. 16, as the motor winding is changed from a low load to a high load, the overload capacity range can be expanded by appropriately switching from the series connection to the parallel connection.

  As described above, by applying the winding switching motor and the starting method, it is possible to improve the efficiency corresponding to a wide range of loads (rotational speed and capacity). In other words, a method that achieves both high efficiency in the low and medium speed range and expansion of the drive range in the high speed range, and stably restarts the compressor maintaining the differential pressure in a short time, and a motor using the same It becomes possible to provide a drive device and a refrigerating and air-conditioning apparatus.

In the above, in 1st Embodiment of this invention, the timing (time) which switches a motor winding was demonstrated as between the intermediate conditions and rated conditions of an air-conditioner. However, specifically, if the winding switching timing is determined using a preset rotation speed, motor current value, motor output, voltage saturation state (state where induced voltage exceeds terminal voltage), etc. good.
In particular, when switching from series connection to parallel connection, maximum efficiency can be maintained by switching in the voltage saturation region. For example, like the timing indicated by the symbol A in FIG. 15, the efficiency curves of the series connection (characteristic line 152) and the parallel connection (characteristic line 153) intersect.
However, in the case of a large-scale system, it is possible to determine the switching timing by actually calculating the efficiency during system driving.
Further, the winding switching motor needs to be designed with a winding specification so that the maximum efficiency can be obtained as a system.

(Second Embodiment: Winding Switching Motor Drive Device)
A winding switching motor driving apparatus according to a second embodiment of the present invention will be described with reference to FIGS.
In the second embodiment, a booster circuit 16 (FIG. 17) is added after the rectifier circuit in the motor drive circuit of the winding switching motor drive device of the first embodiment, and the motor specifications are also changed. It aims to drive a wide range of high efficiency.

<Configuration of Motor Drive Device of Second Embodiment>
FIG. 17 is a diagram illustrating a configuration example of a motor drive circuit of the winding switching motor drive device according to the second embodiment.
17 is different from the configuration of FIG. 2 in that a boost chopper circuit (boost circuit) 16 is added to the subsequent stage of the rectifier circuit 10.
The added step-up chopper circuit 16 includes a step-up reactor 160, a diode 161, and a switching element 162.
By switching the switching element 162, the output voltage of the rectifier circuit 10 can be boosted. Although the basic boost chopper circuit 16 is shown in FIG. 17, an interleave method or other boost circuits may be applied.
Note that in FIG. 17, circuits and elements having the same reference numerals as those in FIG. 2 have the same functions and operations, and thus redundant description is omitted.

<Winding structure of motor of second embodiment>
Next, the winding structure of the motor of the second embodiment will be described.
FIG. 18 is a diagram showing a structure and a state in which the windings of the motor according to the second embodiment are switched. FIG. 18A is a diagram showing a Y-connection by connecting three windings in series for the U phase, the V phase, and the W phase. (B) is one in which each of the U-phase, V-phase, and W-phase windings is Y-connected, and three Y-connections are connected in parallel.
In FIG. 18A, the windings U1, U2, U3, windings V1, V2, V3 and windings W1, W2, W3 of the motor (3) are connected in series, and the motor drive circuit (1). Are connected to the connection terminals U, V, and W (series connection 1Y).
In FIG. 18B, the windings U1, V1, and W1 of the motor (3) form one Y connection, and the windings U2, V2, and W2 form the second Y connection. A third Y connection is formed by the lines U3, V3, and W3 (parallel connection 3Y).

That is, in the first embodiment, the series connection (1Y) and the parallel connection (2Y) are achieved by switching two windings. In the second embodiment, the series connection (1Y) and the parallel connection are achieved by switching three windings. Connection (3Y) is assumed.
In the switching between the series connection and the parallel connection by the three windings, the difference in characteristics between the series connection and the parallel connection becomes more prominent. Therefore, the second embodiment has a low frequency and a high frequency compared to the first embodiment. Further efficiency improvement of the motor can be achieved in each region of the rotational speed.
In addition, although it is obvious that the specific circuit configuration of the winding switching circuit (2) from (a) to (b) of FIG. 18 exists, the description is omitted because it is complicated.

<Waveform at startup in the second embodiment>
FIG. 19 is a diagram illustrating an example of a starting method and a waveform example at the time of starting in the second embodiment.
In the second embodiment, as described above, the step-up chopper circuit 16 is added to the motor drive circuit, and the winding of the motor and the winding switching circuit are switched in series and parallel of three windings. In addition, the startup procedure has been changed.
The waveform at the time of activation in the second embodiment shown in FIG. 19 is different from the waveform at the time of activation in the first embodiment shown in FIG. 11 in that the positioning process is eliminated.

If the rotor position is known even when the motor is stopped, the positioning process is not necessarily required.
In the second embodiment, instead of the positioning process, an initial phase detection pulse is output, an initial phase detection process for detecting the initial phase from the terminal voltage at that time is performed, and driving is performed by energizing 120 degrees from the detected initial phase. is there.
The operation after the 120-degree energization operation is the same as in FIGS.

<The overall efficiency of the motor and inverter of the second embodiment>
FIG. 20 is a diagram illustrating an example of the overall efficiency of the motor and the inverter with respect to the rotation speed according to the second embodiment. FIG. 20 also shows the DC voltage across the smoothing circuit 11 after the output of the step-up chopper circuit 16 in the motor drive circuit. The DC voltage can be boosted by adding the boost chopper circuit 16.
In the second embodiment, as shown in FIG. 18, three windings of each phase (U1 to U3, V1 to V3, W1 to W3) are connected in series (1Y) -parallel connection (3Y). Since switching is performed, a lower speed design is possible in the case of series connection (1Y) than in the case of the first embodiment.
That is, as shown in FIG. 20, the efficiency peak value of the efficiency curve (characteristic line 202) at the time of series connection can be moved to the minimum capacity side.
Here, if the efficiency peak value is moved to the minimum capacity side, it is necessary to perform field-weakening control in the intermediate capacity range, resulting in a decrease in efficiency.
Therefore, when the DC voltage is boosted (characteristic line 204) in the intermediate capacity range, the efficiency curve is reduced as shown in the characteristic line 202B, so that the loss of field weakening control is reduced and the efficiency can be improved.

  Under the rated conditions, the efficiency is improved near the rated capacity by switching to parallel connection (3Y) as shown in FIG. At this time, even if the DC voltage is not boosted (characteristic line 205), the efficiency is improved by the parallel connection (3Y).

  Thereafter, when the rotational speed increases, the DC voltage is boosted as in the intermediate capacity (characteristic line 206), so that the efficiency of the overload capacity area is improved and the overload capacity area is greatly expanded (characteristic line 203 → Characteristic line 203B).

<Rotational speed-torque characteristics of the motor of the second embodiment>
FIG. 21 is a schematic diagram illustrating an outline of the rotational speed-torque characteristics of the motor according to the second embodiment. In addition, it shows the range in which the capacity range (minimum capacity, intermediate capacity, rated capacity, overload capacity) of the air conditioner is located in the rotational speed-torque characteristics.
In FIG. 21, a characteristic line 201 is a conventional rotational speed-torque characteristic (a motor that does not switch the winding).
A characteristic line 202 is a rotational speed-torque characteristic when a motor (winding switching motor) driven by the winding switching drive device of the second embodiment is connected in series. However, the region where the DC voltage is boosted is indicated as the characteristic line 202B along with the characteristic line 202.
A characteristic line 203 is a rotational speed-torque characteristic when a motor (winding switching motor) driven by the winding switching drive device of the second embodiment is connected in parallel. However, the region where the DC voltage is boosted is indicated as the characteristic line 203B along with the characteristic line 203.

As shown in FIG. 21, in comparison with the characteristics of the conventional non-winding-switching motor indicated by the characteristic line 201, the above-described series connection (1Y) -parallel connection (3Y) switching winding switching motor is combined with the boosting operation. As a result, the efficiency improvement in the low speed region (characteristic lines 202 and 202B) and the overload capacity range can be greatly expanded (characteristic line 203 (203B)).
Further, when FIG. 21 is compared with FIG. 16 (only switching of serial connection (1Y) -parallel connection (2Y)), the characteristic line 202 (202B) shown in FIG. 21 increases the torque in the low speed range. . In addition, the characteristic line 203 (203B) widens the high rotational speed region in the high speed region.
That is, in the second embodiment, the combination of the above-described series connection (1Y) -parallel connection (3Y) switching coil switching motor and boosting operation improves the efficiency in the low speed range (characteristic lines 202 and 202B) and overload. The capability range can be greatly expanded (characteristic line 203 (203B)).

  In the second embodiment, the method is changed to the method using the initial phase detection pulse instead of the positioning method of the first embodiment, but this difference is different from the rotational speed-torque characteristic shown in FIG. Unrelated. The rotation speed-torque characteristic shown in FIG. 21 is a characteristic obtained by combining the above-described winding switching motor of series connection (1Y) -parallel connection (3Y) and boosting operation, and is effective.

(Third embodiment: winding switching motor driving device)
Next, as a third embodiment, a description will be given of a configuration in which switching is performed so that half and all of the series-connected windings are used.
FIG. 22 shows a configuration example of a winding switching motor driving device 103 according to the third embodiment of the present invention, a motor (permanent magnet synchronous motor) 30 controlled by the winding switching motor driving device 103, and the motor 30. It is a figure which shows the whole structure and relationship of the compressor 5 which drive.
22 is different from FIG. 1 showing the first embodiment in the configuration of the winding switching circuit 20 and the motor 30 in the winding switching motor driving device 103.

In the first and second embodiments, the winding structure of the motor is described on the assumption that the parallel connection and the series connection are switched. However, for example, half the winding of the series connection winding (the series connection in which the induced voltage is reduced). ) And all the windings (series connection in which the induced voltage increases) can be applied to the present application.
Specifically, in the diagram of the series connection (1Y) in FIG. 4A, in the U phase, the winding U1 and the winding U2 are used in a state of being connected in series, and the winding U1 and the winding U2 are connected. This is a case where terminals are provided between them and only the winding U2 is used.
In addition, the switching is performed similarly for the V phase and the W phase.
In the configuration shown in FIG. 22, the number of output terminals of the motor 30 is six (U1, U2, V1, V2, W1, W2), which is 3 compared to the nine output terminals (FIG. 3) of the motor 3 of FIG. This can be reduced, and it is advantageous to reduce the cost of a built-in motor such as a compressor. However, the winding utilization of the motor is reduced.

(Fourth embodiment: Refrigeration and air conditioning equipment)
In FIG. 14, the motor 3 is driven by the winding switching motor driving apparatus 100 of the first embodiment, the compressor 5 is operated by this motor, and the air conditioner (141, 142: refrigeration air conditioner) on which the compressor 5 is mounted. showed that.
Thus, the motor (3, 30) is driven by the winding switching motor driving device (100, 103) of the first to third embodiments, the compressor 5 is operated by this motor, and the compressor 5 is provided. The refrigeration and air-conditioning equipment can be expected to improve performance due to the above-described improvement in characteristics in the low-speed range and high-speed range of the motor.
The refrigerating and air-conditioning equipment is not limited to the above-described air conditioner. Multi-type air conditioners for buildings, refrigerators, water coolers, ice makers, chillers, vending machines, food refrigeration showcases, etc.

(Other embodiments)
As mentioned above, although embodiment of this invention was described with reference to drawings, this invention is not limited to these embodiment, There may be a design change etc. of the range which does not deviate from the summary of this invention, and the following. An example is given below.

<< Three-stage series-parallel winding switching method >>
In the first and second embodiments, the method of switching the windings in two stages of series and parallel has been described, but the switching is not limited to two stages. Next, a three-stage series / parallel winding switching method will be described.
FIG. 26 is a diagram for explaining a three-stage series-parallel winding switching method in the U phase, where (a) shows the windings U1 to U4 connected in series, and (b) shows U1, U2 and U3, U4. Are connected in parallel, and (c) shows that all the windings of U1 to U4 are connected in parallel.

In FIG. 26 (a), since all the windings of U1 to U4 are connected in series, the motor has excellent characteristics in a low rotational speed region, and (c) shows that all of the windings of U1 to U4 are in parallel. Because it is connected, the motor has excellent characteristics in the high rotation speed range.
However, if the windings U1 to U4 in FIG. 26A are all connected in series to the state in which all windings U1 to U4 in FIG. 26 are connected in parallel, the characteristics are changed at the time of switching. There may be large fluctuations.
In order to reduce this sudden fluctuation in characteristics, in FIG. 26 (b), the windings of U1 and U2 and the windings of U3 and U4 are connected in parallel, and these two are connected in parallel. The windings are connected in series.
That is, more desirable characteristics can be obtained by sequentially shifting or selecting the configurations shown in FIGS. 26A, 26B, and 26C according to the load status.
In addition, although the example which transfers to 3 steps | paragraphs was given in FIG. 26, you may transfer to 4 steps | paragraphs or more.

《Method of using winding part other than half》
In the third embodiment, when the U-phase windings U1 and U2 in FIG. 4A are used in a state of being connected in series, a terminal is provided between the winding U1 and the winding U2, and only the winding U2 is provided. However, the present invention is not limited to the case of two windings U1 and U2.
As shown in FIG. 18 (a), when three windings U1, U2, U3 are connected in series in the U phase, when two windings U2, U3 are connected in series, only the winding U3 is used. There is also a way to switch between cases.

《Method for Δ connection》
In FIG. 4 of the first embodiment and FIG. 18 of the second embodiment, the method of switching the serial connection and the parallel connection in the Y connection has been described. However, the method is not limited to the Y connection.
U-phase windings U1 and U2 are connected in series, V-phase windings V1 and V2 are connected in series, W-phase windings W1 and W2 are connected in series, and U-phases are connected in series. A Δ connection is formed by windings of V phase and W phase.
As a next switching method, the windings U1, V1, and W1 constitute a first Δ connection, the windings U2, V2, and W2 constitute a second Δ connection, and the first Δ connection Y connection and The second Δ connection is connected in parallel.
In this way, there is a method of switching between serial connection and parallel connection not only with Y connection but also with Δ connection.

《Method of mixing Y connection and Δ connection》
In the above, the method of switching the serial connection and the parallel connection with the Y connection and the method of switching the series connection and the parallel connection with the Δ connection have been described, but there is also a method of mixing the Y connection and the Δ connection.
The case where the Y connection is connected in series is the lowest rotation speed region, and the case where the Δ connection is used in parallel is the highest rotation speed region. There is also a method in which a series connection with a Δ connection or a parallel connection with a Y connection is used as an intermediate region of the rotation speed.

《Equipment other than refrigeration and air conditioning equipment》
In the fourth embodiment, the motor (3, 30) is driven by the winding switching motor driving device (100, 103) of the first to third embodiments, and the compressor 5 is operated by this motor. The refrigeration and air conditioning equipment equipped with 5 was explained.
However, since the winding switching motor driving device of the first to third embodiments is effective when driving the motor, the winding switching motor driving device (100, 103) and the motor of the first to third embodiments are effective. A device to which (3, 30) is applied is not limited to a refrigerating and air-conditioning device.
If the motor is allowed to stop temporarily at the time of switching the windings, the winding switching motor driving device and the winding switching motor driving method according to the first to third embodiments in a device using the motor. Is effective and widely available.

(Comparison example of motor starting method)
Next, in order to make the characteristics of the winding switching motor driving device and the winding switching motor driving method of the present invention easier to understand, the characteristics of the motor starting method will be described with reference to a comparative example.
FIG. 27 is a diagram illustrating a starting method of a motor of a comparative example. Note that the activation method shown in FIG. 27 is a position sensorless control method.
In FIG. 27, the horizontal axis represents the history of time. The vertical axis indicates the rotational speed command, current command (Id ^* , Iq ^* ), and motor current (U-phase current) from the top.

Since the position sensorless control method uses an induced voltage, the position of the rotor cannot be detected at the time of stop and at extremely low speed. Therefore, processing called positioning and synchronous operation is necessary. The positioning process is a process in which a direct current is passed through a predetermined phase of the motor winding to attract the rotor to a predetermined position.
In the comparative example, current flows from the U phase to the V phase and the W phase. At this time, if the rotor does not come near the predetermined position, the rotor does not rotate even if the operation shifts to the synchronous operation process.
Therefore, as shown in FIG. 27, it is assumed that the maximum torque is applied to the motor, and a maximum current is passed (Id ^* maximum value, characteristic line 271).

The synchronous operation process is a process of increasing the frequency while flowing an alternating current from the phase positioned at a predetermined position in the process. When alternating current flows, rotational torque is generated and the motor starts to rotate.
However, since the synchronous operation is an open loop, if the load torque is large with respect to the torque generated by the motor, it will step out (stop) immediately.
For this reason, it is assumed that the maximum torque is applied to the motor and the maximum current is supplied (Id ^* maximum value).

However, when the load torque is small, the generated torque of the motor becomes excessive and becomes unstable such as sudden acceleration.
When the rotational speed increases, the control shifts to position sensorless control (sensorless operation).
As described above, positioning and synchronous operation are indispensable for driving a permanent magnet synchronous motor by position sensorless control.
When the technique of the comparative example is applied as a compressor driving device for an air conditioner, since the compressor cannot be driven in a state where an excessive differential pressure is applied, processing for stopping the compressor for a certain time is set.

FIG. 28 is a diagram illustrating the relationship between the capacity of the air conditioner, the discharge pressure of the compressor, and the suction pressure when the comparative example is used.
In FIG. 28, the horizontal axis represents the time course, and the vertical axis represents the relationship between the capacity of the air conditioner, the discharge pressure of the compressor, and the suction pressure. In addition, the compressor stop time is also shown.
As described above, when the starting method of the comparative example is used, the compressor is stopped for a predetermined time (compressor stop time 281), and the discharge pressure 283 and the suction pressure 282 are balanced before starting. Therefore, it takes time until the capacity 284 of the air conditioner reaches the capacity before stopping.

(Contrast between the first embodiment of the present invention and a comparative example)
When comparing FIG. 28 showing the relationship between the characteristics of the comparative example and FIG. 13 showing the relationship between the characteristics of the first embodiment of the present invention, the compressor stop time 131 of FIG. The time is significantly shorter than the machine stop time 281.
Therefore, when the winding switching motor driving device and the winding switching motor driving method according to the first embodiment of the present invention are used, the motor 3 (FIG. 1) and the compressor 5 (FIG. 1) are stably provided in a short time. You can restart.

DESCRIPTION OF SYMBOLS 1 Motor drive circuit 2, 20 Winding switching circuit 3, 30 Permanent magnet synchronous motor, motor 4 Control circuit 5 Compressor 10 Rectifier circuit 11 Smoothing circuit 12 Inverter circuit 13 Current detection circuit 14 Terminal voltage detection circuit 14R Resistance 15 DC voltage detection Circuit 16 Booster circuit, Booster chopper circuit 21, 22, 23, 24 Switch 100, 103 Winding switching motor drive device 141 Air conditioner indoor unit (refrigeration air conditioner)
142 Air conditioner outdoor unit (refrigeration air conditioner)
160 Step-up reactor 161 Diode 162 Switching element 401 Iq ^* Setting process 401A Speed control process 401B Initial value selection process 401C 120 degree initial value process 401D 180 degree initial value process 402 Current control process 403 Vector calculation process 404 180 degree conduction speed / position estimation Process 405 120-degree energization speed / position estimation process 406 Voltage calculation process 407 Voltage command selection / pattern generation process 408 PWM signal output process 409 Energization method switching determination process 410 Speed selection process 411 Current reproduction process 412 Id ^* Setting process U1 to U3 V1-V3, W1-W3 Winding, Winding

Claims (13)

A motor drive circuit for driving a permanent magnet synchronous motor;
A winding switching circuit for switching the wiring connection of the permanent magnet synchronous motor;
A control circuit for controlling the motor drive circuit and the winding switching circuit;
With
Under the control of the control circuit, the motor driving circuit stops the permanent magnet synchronous motor, and under the control of the control circuit, the winding switching circuit switches connection of the windings of the permanent magnet synchronous motor. When the motor driving circuit restarts the permanent magnet synchronous motor, the control circuit calculates the initial motor current value of the permanent magnet synchronous motor from the motor current value before stopping and the connection state of the windings. A winding switching motor driving device, characterized by being set to be equal to or greater than a calculated motor current value. In claim 1,
The motor drive circuit is controlled by the control circuit,
As the energization method after restarting the permanent magnet synchronous motor, there are two energization methods of a 120-degree energization method and a 180-degree energization method,
When switching between the 120-degree energization method and the 180-degree energization method, the motor current initial value after switching between the two energization methods is set based on the motor current value before switching the energization method. A winding-switching motor drive device. In claim 2,
The initial value of the motor current after the switching of the energization method is set to the initial value of the motor current before the stop, or the initial value of the motor current that is equal to or greater than the motor output torque before the switching of the energization method, Winding switching motor drive device. In any one of Claims 1 thru | or 3,
The winding switching circuit driving device, wherein the winding switching circuit switches the connection of windings of the permanent magnet synchronous motor between a serial connection and a parallel connection. In any one of Claims 1 thru | or 3,
The winding switching circuit is characterized in that the winding connection of the permanent magnet synchronous motor is switched between a series connection in which the induced voltage is increased and a series connection in which the induced voltage is reduced. In claim 1,
The winding switching circuit switches the connection of the windings of the permanent magnet synchronous motor from a connection in which the induced voltage is increased to a connection in which the induced voltage is lowered, and when the switching is performed, the induced voltage exceeds the terminal voltage of the winding. A winding switching motor driving device characterized by being in a state. In claim 1,
The motor drive circuit has a booster circuit,
The winding switching motor driving device, wherein the voltage of the booster circuit is increased in accordance with an increase in load or rotation speed of the permanent magnet synchronous motor. A method for controlling a winding switching motor composed of a permanent magnet synchronous motor,
A motor drive circuit drives the permanent magnet synchronous motor;
The winding switching circuit switches the winding of the permanent magnet synchronous motor,
A control circuit controls the motor drive circuit and the winding switching circuit;
Under the control of the control circuit, the motor driving circuit stops the permanent magnet synchronous motor, and under the control of the control circuit, the winding switching circuit switches connection of the windings of the permanent magnet synchronous motor. When the motor driving circuit restarts the permanent magnet synchronous motor, the control circuit calculates the initial motor current value of the permanent magnet synchronous motor from the motor current value before stopping and the connection state of the windings. A drive control method for a winding switching motor, characterized by being set to be equal to or greater than a calculated motor current value. In claim 8,
The motor drive circuit is controlled by the control circuit,
As the energization method after restarting the permanent magnet synchronous motor, there are two energization methods of a 120-degree energization method and a 180-degree energization method,
When switching between the 120-degree energization method and the 180-degree energization method, the motor current initial value after switching between the two energization methods is set based on the motor current value before switching the energization method. A drive control method for a winding switching motor. In claim 9,
The initial value of the motor current after the switching of the energization method is set to the initial value of the motor current before the stop, or the initial value of the motor current that is equal to or greater than the motor output torque before the switching of the energization method, Drive control method for winding switching motor. In any one of Claims 8 to 10,
The winding switching circuit switches the connection of windings of the permanent magnet synchronous motor between a serial connection and a parallel connection. A permanent magnet synchronous motor;
A motor driving circuit for driving the permanent magnet synchronous motor, a winding switching circuit for switching the wiring connection of the permanent magnet synchronous motor, and a control circuit for controlling the motor driving circuit and the winding switching circuit. A winding switching motor driving device,
A compressor driven by the permanent magnet synchronous motor;
With
The motor driving circuit stops the permanent magnet synchronous motor by the control of the control circuit of the winding switching motor driving device, and the winding switching circuit connects the windings of the permanent magnet synchronous motor by the control of the control circuit. When the motor drive circuit restarts the permanent magnet synchronous motor by the control of the control circuit, the control circuit sets the motor current initial value of the permanent magnet synchronous motor as the motor current value before stopping. A refrigerating and air-conditioning apparatus characterized by being set to a motor current value or more calculated from the connection state of the winding. In claim 12,
The motor drive circuit is controlled by the control circuit,
As the energization method after restarting the permanent magnet synchronous motor, there are two energization methods of a 120-degree energization method and a 180-degree energization method,
When switching between the 120-degree energization method and the 180-degree energization method, a motor current initial value after switching the energization method is set based on a motor current value before switching the energization method. Air conditioning equipment.

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