JP4124425B2 - Electric motor and driving device thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electric motor and a driving device thereof, and more particularly to an electric motor used for a refrigeration apparatus or the like.
[0002]
[Prior art]
In refrigeration / air-conditioning devices (hereinafter referred to as refrigeration devices), the drive of inverters for compressor motors and the use of synchronous motors for compressor motors are progressing due to demands for higher efficiency. That is, from the viewpoint of the synchronous machine, the use of a permanent magnet type synchronous motor and a reluctance type synchronous motor can be cited, and Japanese Patent Application Laid-Open No. 2001-346364 discloses the application of this permanent magnet type synchronous motor.
[0003]
In addition, in applications where this permanent magnet type synchronous motor is operated with a commercial power supply, for example, a configuration as a self-starting synchronous motor with a cage as disclosed in Japanese Patent Laid-Open No. 2001-003864 is proposed, For example, as disclosed in Japanese Patent Laid-Open Nos. 2000-130824 and 2001-258224, a configuration is proposed in which an inverter is started and switched to a commercial power source.
[0004]
Based on this, driving motors for compressor applications are generally driven by high-speed rotation using a two-pole motor. However, when using a synchronous motor, a multi-pole machine with four or more poles is a countermeasure for efficiency and vibration. The necessary machine rotation speed is secured by supplying a high-frequency power supply voltage higher than the commercial power supply by inverter operation.
[0005]
Here, in the case of a compressor, especially in the case of a refrigerator, it is also necessary to perform an emergency operation in which the compressor is continuously driven by a commercial power supply even when the inverter is damaged. During this emergency operation, the machine rotates during commercial power supply operation and during operation by the inverter. The difference in number, that is, the lack of refrigeration capacity particularly during rated operation, is a problem that should be avoided.
[0006]
In the conventional electric motor, Japanese Patent Application Laid-Open No. 2001-157427 discloses the problem of achieving both the advantage of the high efficiency of the synchronous machine and the matching of the machine rotational speed when driving the inverter and the commercial power source. As disclosed, the operation as a 4-pole synchronous motor and the operation as a 2-pole induction motor are realized by switching the stator winding to one corresponding to each of the 2-pole and 4-pole. Japanese Patent Laid-Open No. 2001-227778 discloses that a compressor motor is operated by a two-pole permanent magnet synchronous motor.
[0007]
[Problems to be solved by the invention]
Focusing on conventional motors used for compressors of refrigeration systems, for example, rotation control was performed by frequency control using an inverter using a 4-pole permanent magnet type synchronous motor and a reluctance type synchronous motor. The problem like this has arisen. That is, in the stator winding switching method corresponding to 2 poles and 4 poles, the characteristics in each operation can be individually adjusted, so there is no problem, but two types of windings are wound on the stator. Therefore, the increase in size and cost is inevitable.
[0008]
The present invention has been made in view of the above, and solves the problem of the high efficiency of the synchronous machine and the matching of the machine rotation speed when driving the inverter and the commercial power supply with a simpler configuration, and further for four poles. Alternatively, it is an object of the present invention to provide an electric motor that does not require two types of windings for two poles to be individually wound and a driving device thereof.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, an electric motor according to the present invention comprises two sets of three-phase windings disposed on a stator at positions that are mechanically and electrically opposed to each other, and connection terminals for the three-phase windings of each set. With 6 terminals to pull out the part to the outside Voltages of the same phase are supplied to opposite windings of two sets of three-phase windings by a three-phase commercial power source connected to switching means provided for each set of two sets of three-phase windings. Thus, a two-pole electric motor is constructed by obtaining a three-phase power source, and a voltage type inverter composed of a one-way switching element and an anti-parallel rectifier element is connected in parallel with the opening / closing means. A four-pole motor is configured by supplying a six-phase power source by supplying voltages of opposite phases to opposite windings of two sets of three-phase windings by a voltage-type inverter supplied with electric power. It is characterized by that.
[0010]
According to the present invention, as in the prior art There is no need to separately wind two types of windings for 4 poles or 2 poles, and a simple winding structure consisting of two sets of three-phase windings, a two-pole motor and a voltage type inverter with a three-phase commercial power supply 4-pole motor by Can be obtained.
[0013]
The electric motor according to the next invention is characterized in that, in the above invention, the rotor is provided with a permanent magnet or a reluctance torque support structure.
[0014]
According to the present invention, a highly efficient synchronous motor can be obtained.
[0015]
The electric motor according to the next invention is characterized in that, in the above invention, the rotor has an induction cage structure.
[0016]
According to the present invention, consistency can be maintained in terms of the characteristics of the motor when switching from four poles to two poles.
[0017]
The electric motor according to the next invention is characterized in that, in the above invention, the electric motor is applied to drive a compressor of a refrigeration apparatus.
[0018]
According to the present invention, with respect to the operation of the compressor, the winding structure can be simplified and the features of high efficiency and energy saving can be sufficiently exhibited.
[0021]
An electric motor drive device according to the next invention is configured to connect a three-phase commercial power source to a set of three-phase windings of an electric motor via an opening / closing means, and a reverse-parallel switching element in parallel with the opening / closing means. A voltage type inverter composed of a rectifier element is connected, and two sets of this switching means and voltage type inverter are provided corresponding to the two sets of three-phase windings of the motor, and all the voltage type inverters are opened during driving of the motor. The rear opening / closing means is closed and switched to a three-phase commercial power source.
[0022]
According to the present invention, it is possible to suitably perform the three-phase and six-phase operations when driving the inverter, and it is possible to smoothly switch between the inverter driving and the commercial power source driving. In this case, simultaneous switching becomes unnecessary, and surge can be prevented at the time of switching.
[0023]
The motor drive device according to the next invention is the above-described invention, wherein the open / close means is connected so as to be a two-pole motor when driven by a three-phase commercial power supply, and when driven by a voltage type inverter, The voltage type inverter control is performed so as to be a pole motor or a quadrupole motor.
[0024]
According to the present invention, it is possible to perform the three-phase power drive by the inverter and the opening / closing means and the six-phase power drive by the voltage type inverter, and the switching of the power drive becomes smooth.
[0025]
The motor drive apparatus according to the next invention is characterized in that, in the above invention, the inverter operates as a four-pole synchronous motor when the inverter is driven, and operates as a two-pole induction motor when the three-phase commercial power source is driven.
[0026]
According to the present invention, when switching from a voltage type inverter to a commercial power source and switching from four poles to two poles, consistency can be maintained in terms of the characteristics of the motor.
[0027]
In the motor drive apparatus according to the next invention, in the above invention, the voltage type inverter capable of generating a six-phase voltage from two sets of three-phase power supplies has a PWM timing based on comparison of an output waveform and a carrier waveform by a program calculation or a control circuit. When the control is performed as a two-pole motor, a carrier waveform whose phase is inverted at the time of PWM control of the inverter arm that generates a common-phase voltage is used.
[0028]
According to the present invention, it is possible to easily obtain a three-phase power source out of three phases and six phases only by using a carrier waveform having an inverted phase, thereby obtaining a two-pole motor. In addition, carrier frequency is canceled by canceling the frequency component of the carrier waveform, the noise is reduced by the cancellation effect of PWM switching noise, the leakage current is reduced, the loss such as iron loss is reduced, and the stress of the smoothing capacitor is also suppressed.
[0029]
In the motor drive apparatus according to the next invention, in the above invention, the voltage type inverter capable of generating a six-phase voltage from two sets of three-phase power supplies has a PWM timing based on comparison of an output waveform and a carrier waveform by a program calculation or a control circuit. The drive signal applied during PWM control of the inverter arm that generates a reverse-phase voltage when controlling as a four-pole motor is used for each of the three-phase power supply signals. It is characterized by being exchanged with an arm.
[0030]
According to this invention, it is possible to easily obtain a 6-phase power source by using a carrier waveform having an inverted phase and exchanging the drive signal between the upper arm and the lower arm, thereby obtaining a four-pole motor. In addition, carrier frequency is canceled by canceling the frequency component of the carrier waveform, the noise is reduced by the cancellation effect of PWM switching noise, the leakage current is reduced, the loss such as iron loss is reduced, and the stress of the smoothing capacitor is also suppressed.
[0031]
The motor drive apparatus according to the next invention is characterized in that, in the above invention, the arms of the voltage type inverter are close to each other and fixed to the same casing.
[0032]
According to the present invention, the noise component canceling effect can be improved due to the reverse phase of the frequency component of the carrier, and the canceling effect of the noise component generated between the grounds can be improved by the arms arranged close to each other.
[0033]
The motor drive apparatus according to the next invention is characterized in that, in the above invention, the wiring connecting the voltage type inverter and the motor is close to each other.
[0034]
According to the present invention, it is possible to improve the noise component cancellation effect due to the reverse phase of the frequency component of the carrier.
[0035]
In the motor drive device according to the next invention, in the above invention, the six-phase voltage type inverter is provided with a switching element breakage detecting means, and the phase in which the breakage is detected is always off, and the motor is controlled only by controlling the other phases. It is characterized by being driven.
[0036]
According to the present invention, when the short circuit breakage is 1 or less, the rotating magnetic field is generated by the operation of the remaining five phases without operating the phase (arm) including the damaged element, and the electric motor is The rotation can be controlled.
[0037]
According to another aspect of the present invention, there is provided an electric motor drive device comprising the restraint operation control means for controlling the six-phase voltage type inverters so that the outputs of the two sets of three-phase output inverters cancel each other from the rotating magnetic field. It is characterized by that.
[0038]
According to the present invention, the electric motor does not rotate, and only a heat generation effect is obtained, and the residual heat of the electric motor is used as exhaust heat, and the effect of vaporization movement of the refrigerant around the electric motor is obtained by applying it to the refrigerator compressor.
[0039]
The electric motor drive device according to the next invention is characterized in that, in the above invention, the electric motor drive device is applied to drive a compressor of a refrigeration apparatus.
[0040]
According to the present invention, it is possible to obtain a drive device suitable for a compressor of a refrigeration apparatus by enabling a high-efficiency merit and matching of machine rotation speeds when driving an inverter and a commercial power supply with a simple configuration. I was able to.
[0041]
DETAILED DESCRIPTION OF THE INVENTION
Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
[0042]
Embodiment 1 FIG.
FIG. 1 shows a circuit configuration of an electric motor and a driving apparatus thereof according to Embodiment 1 of the present invention. In FIG. 1, the electric motor and its driving device are inserted between a three-phase power source 1, a motor 2 having a total of six terminals including U 1, V 1, W 1, U 2, V 2, and W 2, and between the three-phase power source 1 and the motor 2. Opening / closing means 3 (divided into 3A and 3B in the figure), rectifying means 4 of the three-phase power source 1, DC smoothing capacitor 5, voltage type six-phase inverter 6 (divided into three-phase inverters 6A and 6B in the figure) Consists of.
[0043]
Here, the opening / closing means 3 contacts and separates the three phases of the R, S, and T phases of the three-phase power source 1 and the terminals U1, V1, and W1 (3A side) U2, V2, and W2 (3B side) of the electric motor 2. R, U1, U2, S, V1, V2, T, W1, W2 correspond to each other.
[0044]
As for the inverter 6, the inverter output arms X1, Y1, Z1 (6A side) X2, Y2, Z2 (6B side) and the terminals U1, V1, W1, U2, V2, and W2 of the electric motor 2 are connected. X1 and U1, Y1 and V1, Z1 and W1, X2 and U2, Y2 and V2, and Z2 and W2 correspond to each other.
[0045]
Further, the stator of the electric motor 2 having the terminals U1, V1, W1, U2, V2, and W2 is configured as shown in FIG. In FIG. 2, for the sake of simplicity, a concentrated winding structure is shown, but the concept is the same for distributed winding.
[0046]
In FIG. 2A, the stator iron core 7 is formed with six salient poles (concentrated winding salient poles in FIG. 2) every 60 ° in mechanical angle, and each salient pole has a winding end U1A.・ U1 winding with U1B, V1 winding with winding ends V1A and V1B, W1 winding with winding ends W1A and W1B, U2 winding with winding ends U2A and U2B, winding ends V2A and V2B And a W2 winding having winding ends W2A and W2B are wound, and an N pole is formed on the black circle side by energization from the winding ends A to B of each winding. In addition, each phase of the U1 winding, the V1 winding, the W1 winding, the U2 winding, the V2 winding, and the W2 winding is arranged in the order of U1, W2, V1, U2, W1, and V2 in the clockwise direction. The windings U2, V1 and V2, and W1 and W2 are opposed to each other. That is, two sets of three-phase windings that are positioned so as to be mechanically opposed to each other are arranged in each winding of the stator.
[0047]
Here, the U1 winding is wound such that the side that is not close to the rotor becomes the N pole of the magnet when a current flows in the direction from the winding end U1A to U1B. The W2 winding is wound so that the side close to the rotor becomes the N pole of the magnet when a current flows from the winding end W2A to W2B. Furthermore, the V1 winding is wound so that the side that is not close to the rotor becomes the N pole of the magnet when a current flows in the direction from the winding end V1A to V1B. Further, the U2 winding is wound so that the side close to the rotor opposite to the U1 winding is the N pole of the magnet when a current flows in the direction from the winding end U2A to U2B. The W1 winding is wound such that when a current flows in the direction from the winding end W1A to W1B, the side not close to the rotor opposite to the W2 winding is the N pole of the magnet. The V2 winding is wound so that the side close to the rotor opposite to the V1 winding is the N pole of the magnet when a current flows in the direction from the winding end V2A to V2B.
[0048]
As shown in FIG. 2 (b), there are two types of connection methods for stator windings that take such a winding state: Δ connection and Y connection. Δ connection is as follows: U1 terminal at winding ends U1A and W1B, V1 terminal at winding ends U1B and V1A, W1 terminal at winding ends V1B and W1A, W2 terminal at winding ends V2B and W2A, and winding end W2B. U2A is connected to the U2 terminal, and winding ends U2B and V2A are connected to the V2 terminal.
[0049]
As the Y connection, the winding ends U1B, V1B, and W1B constitute a first neutral point, and the winding ends U2B, V2B, and W2B constitute a second neutral point, and the winding end U1A is a U1 terminal, The winding end V2A is connected to the V2 terminal, the winding end W1A is connected to the W1 terminal, the winding end U2A is connected to the U2 terminal, the winding end V2A is connected to the V2 terminal, and the winding end W2A is connected to the W2 terminal.
[0050]
Under such a configuration, voltages are applied to the U, V, and W windings of each phase as shown in FIG. 3, and U1 = U2 and V1 = V. 2 , W1 = W2 (where = means the same phase), a two-pole motor can be configured clockwise in the drawing by applying a three-phase voltage in the U → V → W phase rotation direction. As shown in FIG. 4, voltages are applied to the U, V, and W windings of each phase, and U1 = −U2, V1 = −V2, and W1 = −W2 (where “−” means reverse phase) A four-pole motor can be configured clockwise in the drawing by applying a six-phase voltage consisting of in the direction of phase rotation of U → W → V. That is, the stator has two sets of three-phase windings that are electrically opposed to each other (electrically in phase or in phase).
[0051]
In FIG. 1, the connection of the opening / closing means 3 is U1 = U2 and V1 = V with respect to the three-phase power source 1. 2 , W1 = W2 is connected, so it is compatible with two-pole motors. The inverter 6 can cope with both two and four poles by realizing each arm output state equivalent to the voltage application state of FIGS. 3 and 4 by PWM control.
[0052]
U1 = U2, V1 = V on the U, V, W windings of each phase 2 When a two-pole motor that applies a three-phase voltage consisting of W1 = W2 in the direction of phase rotation of U → V → W is to be achieved by inverter driving, as shown in FIG. A contrivance is made such that carriers that are triangular waves for cutting a voltage waveform that is a sine wave are reversed in phase with respect to the three-phase inverter 6A / 6B.
[0053]
In FIG. 6, the output PWM waveform generation state of the half cycle of each phase where U1 = U2 is shown as a representative example, but the same applies to other phases and other phases. In FIG. 6, PWM is a principle in which a triangular wave of a carrier cycle and a voltage waveform are superimposed and generated by comparing both waveforms to obtain a rectangular wave as shown, and at the rising and falling times of this rectangular wave. Inverter commutation takes place.
[0054]
Here, as shown in the figure, the same voltage waveforms applied to the windings U1 and U2 are compared with a triangular wave having an opposite phase, so that the arms X1 and X2 of the inverter 6 are crossed at the intersection of both waveforms. The switching element is turned on and off, but the phase of the carrier frequency component contained in the output waveform which is a rectangular wave is inverted due to the triangular wave having the opposite phase.
[0055]
This cancels out the frequency component of the carrier waveform, leading to a reduction in carrier sound. Further, it is possible to realize a reduction in noise by a canceling effect of PWM switching noise based on the carrier waveform and a reduction in leakage current as one of the influences.
[0056]
Further, since the total carrier component current flowing through the iron core is reduced by the canceling effect, the loss such as iron loss is reduced, and a cost reduction effect such as an increase in the thickness of the iron core material can be expected.
[0057]
Similarly, the total carrier component current decreases due to the canceling effect, so that the inflow and outflow of current to the smoothing capacitor is canceled out, and stress on this capacitor is also suppressed. And cost reduction can be expected.
[0058]
Although a general triangular wave comparison method is used here as a PWM waveform generation method, the same effect can be obtained by changing the vector output order in other methods such as vector pattern selection.
[0059]
A voltage is applied to the U, V, and W windings of each phase described above, and a 6-phase voltage including U1 = −U2, V1 = −V2, and W1 = −W2 is applied in the phase rotation direction of U → W → V. Even when trying to achieve a four-pole motor to be driven by an inverter, a carrier that is a triangular wave that cuts a voltage waveform that is a sine wave having opposite phases as shown in FIG. The idea is to make it out of phase.
[0060]
In FIG. 7, the output PWM waveform generation state of a half cycle of U1 = −U2 is shown as a representative example, but the same applies to other phases and other phases. In FIG. 7, as in FIG. 6, the PWM is generated by comparing the triangular waveform of the carrier period and the voltage waveform and comparing the two waveforms in principle to obtain a rectangular wave as shown in the figure. The commutation of the inverter is performed at the time of falling. Also here, as shown in the figure, the opposite phase voltage waveforms applied to the windings U1 and U2 are compared with the opposite phase triangular wave, so that the arm of the inverter 6 is crossed at the intersection of both waveforms. The switching elements X1 and X2 are on / off controlled.
[0061]
Here, as shown in FIG. 7, in the actual PWM output, a slight blank period Td (upper and lower short-circuit prevention period) is provided to prevent the upper arm and the lower arm from being simultaneously turned on. Further, when the U2 winding output is generated with respect to the U1 winding output in order to obtain a four-pole motor, the drive signals for the upper arm and the lower arm are switched. By doing so, the U2 winding output waveform is in reverse phase with respect to the U1 winding.
[0062]
As a result, the frequency component of the carrier waveform is canceled, so that carrier noise can be reduced, noise can be reduced due to the effect of canceling PWM switching noise, and leakage current can be reduced as one of the effects. In particular, in this control, since the rising / falling waveforms of the output voltage rectangular wave in the U1 winding and the U2 winding are completely at the same timing in the opposite directions as shown in the figure, the noise and leakage current canceling effect is Very large.
[0063]
Further, since the total carrier component current flowing through the iron core is reduced due to the canceling effect, a cost reduction effect such as an increase in the thickness of the iron core material can be expected.
[0064]
Similarly, the total carrier component current is reduced due to the canceling effect, so that the stress on the smoothing capacitor is also suppressed, and it is possible to expect a longer life and / or a reduction in the size and cost of parts corresponding to the longer life.
[0065]
Although a general triangular wave comparison method is used here as a PWM waveform generation method, the same applies to other methods such as vector pattern selection because of the operation at the drive signal level of each generated upper and lower arm. The effect is obtained.
[0066]
Here, the rotor side structure as an electric motor is not particularly shown, but considering the compatibility between the effect of starting and operation with a commercial power source as an induction machine and the efficiency during normal operation as a synchronous machine, From the viewpoint of securing the machine speed in the operating state, it is effective to apply a 4-pole synchronous rotor with a cage so that it can be operated as a 2-pole induction machine and a 4-pole synchronous machine. And as a structure of a synchronous rotor here, a permanent magnet built-in type and a reluctance torque type structure can be utilized.
[0067]
In addition, as an application of the electric motor and its driving device described above, a compressor driving of a refrigeration device is effective as a product that requires both energy saving and an emergency operation request when a partial function of the device is lost. It is believed that there is. Normally, high-efficiency energy-saving operation is realized as a four-pole synchronous machine by inverter operation, and when one of the three-phase inverters 6A or 6B of the inverter 6 is damaged, two poles are supplied by a commercial power source by turning on the switching means 3. Operation can be continued as an induction machine. By making the rated machine rotation speed in a 4-pole synchronous machine equivalent to a 2-pole induction machine, it is possible to maintain the consistency of characteristics as an electric motor.
[0068]
In a normal inverter control system, a three-phase output is common, but this time, both the three-phase output and the six-phase output are driven as a six-phase inverter. In addition to the effects of low noise and low noise as described above, this also expects the effect of suppressing component costs based on the increase in market distribution due to the downsizing of the inverter main circuit elements due to the fact that the required capacity of the elements is halved. Yes. In particular, when the element capacity can be reduced to 30-50A or less by using 6 phases, the current component price level is extremely cost-effective with respect to the capacity because the inverter parts are changed from the module structure to the DIP or SIP structure. The I can expect a lot.
[0069]
Embodiment 2. FIG.
Next, a second embodiment of the present invention will be described. In the configuration of FIG. 1, the number of phases of the electric motor 2, the opening / closing means 3, and the inverter 6 is not limited to six, but may be three. However, in any case, the effect is particularly effective when the electric motor is a synchronous machine. A control method for switching from a certain inverter operation to commercial power operation will be described. Here, a case will be described in which the number of poles when the inverter is driven and when the commercial power source is driven is the same.
[0070]
In FIG. 5, it is determined in step S1 whether or not the inverter is operating. If it is operating, the process proceeds to step S2, and if the inverter is not operating, this control is terminated. In step S2, it is determined whether or not the phases of the inverter output and the power supply voltage match. If they match, the process proceeds to step S3. If they do not match, this control is terminated. In step S3, all output switching elements of the inverter are turned off (open), and the process proceeds to step S4. In step S4, the commercial power supply switching means 3 is turned on (closed), and this control is terminated.
[0071]
As can be seen from the description of FIG. 5, when switching between the inverter power supply and the commercial power supply, it is not necessary to measure the timing of supplying voltage simultaneously from both power supplies, and when the voltage supply from the inverter output is stopped. There is a feature that it is not necessary to have an opening / closing means for opening the output circuit.
[0072]
Here, the behavior until the inverter power supply is shut off in step S3 and connected to the commercial power supply in step S4 will be further described. In this case, in the switching from the inverter power source to the commercial power source, the processing of the motor current at the time of switching is a problem of the generation of a surge voltage due to the interruption of the continuity current. During this switching, the motor is used for the return of the inverter. A surge voltage is not generated because a path is secured for the current that is connected to the DC smoothing capacitor via the diode, that is, the current that continues to flow through the motor.
[0073]
After switching to the commercial power supply, the inverter freewheeling diode is always connected, but for the inverter 6, only the rectification operation from the secondary side is added, and the smoothing capacitor 5 has already been connected. There is no particular problem when the battery is fully charged. Also, for the electric motor 2, only the rectifying means 4 is connected to the three-phase power source 1 in parallel with the electric motor 2, and the operation is not affected.
[0074]
In addition, since the return diode of the inverter 6 remains connected even when the commercial power supply is shut off, a flow path for the motor continuity at the time of the shut-off is ensured, and an effect of suppressing the surge voltage is obtained.
[0075]
Thus, in the synchronous switching during operation from the inverter power supply to the commercial power supply, it is not necessary to configure a particularly complicated circuit, and smooth switching can be realized. The above-described switching operation is often required for a synchronous machine that is difficult to start, but the same control can be performed by an induction machine in order to eliminate the loss caused by the inverter.
[0076]
Embodiment 3 FIG.
Next, a third embodiment of the present invention will be described. In this embodiment, a structural measure for noise suppression in the configuration of FIG. 1 will be described with reference to FIG. FIG. 8 shows a heat sink 8 for heat dissipation and a connection wiring 9 to which the inverter 6 is fixed. That is, the inverter 6A / 6B is fixed on the heat sink 8, and the output of the inverter 6A / 6B is connected to the electric motor 2 through the connection wiring 9. In this case, the connection wiring 9 has the U1 terminal and U2 terminal of the inverter output, the V1 terminal and V2 terminal, and the W1 terminal and W2 terminal close to each other. These close wirings are controlled so that the carrier frequency components are in opposite phases during inverter operation, and the cancellation effect is increased by arranging them close to each other.
[0077]
As for the noise generated between the ground due to the switching operation of each inverter element, it is effective to arrange the inverter elements in the vicinity of each other in order to increase the effect of canceling the noise component between the elements arranged in the vicinity through the heat sink. It is.
[0078]
When the above concept is expanded, it is also effective for noise cancellation to arrange opposing arms such as U1 terminal and U2 terminal in the same module.
[0079]
Embodiment 4 FIG.
Next, a fourth embodiment of the present invention will be described. In the fourth embodiment, an emergency operation at the time of an overcurrent abnormality due to an inverter operation will be described with reference to FIG.
[0080]
As shown in FIG. 1, in the case of applying a 6-phase inverter having 2 sets of 3 phases, a rotating magnetic field can be secured although an increase in distortion is caused for an output phase loss for one phase. Even without switching to the power supply drive, an emergency operation with an inverter drive is possible. In this case, a flowchart of emergency operation is shown in FIG. In FIG. 9, temporary variables i and j are used, where i indicates the positions on the P side and N side of each arm of the inverter, and j indicates the number of failures.
[0081]
That is, the correspondence between i and each switching element of the inverter 6 is as follows: i = 1 = X1P side, i = 2 = X1N side, i = 3 = Y1P side, i = 4 = Y1N side, i = 5 in FIG. = Z1P side, i = 6 = Z1N side, i = 7 = X2P side, i = 8 = X2N side, i = 9 = Y2P side, i = 10 = Y2N side, i = 11 = Z2P side, i = 12 = Z2N side.
[0082]
In the flowchart of FIG. 9, in the emergency operation at the time of an overcurrent abnormality, in step S11, the inverter output is stopped in response to the overcurrent abnormality, and the process proceeds to step S12. In step S12, the temporary variable i = 1, that is, the position on the X1P side, j = 0, that is, the number of failures is assumed, and the process proceeds to step S13. In step S13, the i-th (here, 1) switching element is turned from OFF to ON, and the process proceeds to step S14. In step S14, it is determined whether or not an overcurrent interruption occurs due to the i-th (here, the first) ON operation in step S13. If it occurs, the process proceeds to step S15, and if not, the process proceeds to step S17. When the current interruption occurs, in step S15, the arm including the i-th (here, the first) switching element is fixed to be off at both the P side and the N side, and the process proceeds to step S16. In step 16, the number of failures j = j + 1 is set, and the process proceeds to step S17. In step S17, the i-th (here, the first) switching element is turned from on to off, and the process proceeds to step S18. In step S18, the position is shifted to i = i + 1, and the process proceeds to step S19. In step S19, it is determined whether or not the position i is larger than 12. If it is larger, the process proceeds to step S20, and if it is 12 or less, the process returns to step S13 and steps S13 to S18 are repeated. In step S20, it is determined whether or not the number of failures j = 0. If it is 0, the present control is terminated, and if it is not 0, the process proceeds to step S21. In step S21, it is determined whether j = 1, and if it is 1, this control is terminated, and if not, the process proceeds to step S22. In step S22, at the time of driving the motor after the next time, switching to commercial power supply driving is performed, and this control is finished. In this case, the overcurrent determination in step S14 detects a defective arm by detecting a short-circuit current when an element paired with the same arm as the switching element operated at that time is short-circuited. I am doing so.
[0083]
By controlling in this way, when the short-circuit damage of the switching element is 1 or less, the rotating magnetic field is generated by the operation of the remaining five phases without operating the phase (arm) including the damaged element. It is possible to generate and control the rotation of the electric motor.
[0084]
Embodiment 5. FIG.
Next, a fifth embodiment of the present invention will be described. In the fifth embodiment, a method of generating heat without rotating an electric motor will be described with reference to FIG. The basic configuration is the same as in FIG.
[0085]
When the six-phase applied voltages shown in FIG. 10A are applied to the motor, the rotating magnetic fields of the U1, V1, and W1 windings are applied clockwise, U2 winding, The rotating magnetic fields of the W2 winding and the V2 winding are counterclockwise. When the same frequency and the same voltage value are used, the combined magnetic field reciprocates as shown in FIG. 10B, and no rotating magnetic field is generated. Therefore, the electric motor does not rotate and only the heat generation effect is obtained.
[0086]
This is effective for the residual heat of the electric motor and the vaporization movement of the refrigerant around the electric motor when applied to the refrigerator compressor. In the refrigerator compressor, if the liquid refrigerant is advanced to the compression process as it is, it causes overcurrent interruption due to overload and leads to mechanical breakage of the compressor, so this heat generation process is important.
[0087]
【The invention's effect】
As described above, according to the invention of this electric motor, two sets of three-phase windings disposed on the stator at positions that are mechanically and electrically opposed to each other, and connection terminals of the three-phase windings of each set With 6 terminals to pull out the part to the outside Voltages of the same phase are supplied to opposite windings of two sets of three-phase windings by a three-phase commercial power source connected to switching means provided for each set of two sets of three-phase windings. Thus, a two-pole electric motor is constructed by obtaining a three-phase power source, and a voltage type inverter composed of a one-way switching element and an anti-parallel rectifier element is connected in parallel with the opening / closing means. A four-pole motor is configured by supplying a six-phase power source by supplying voltages of opposite phases to opposite windings of two sets of three-phase windings by a voltage-type inverter supplied with electric power. As usual, There is no need to separately wind two types of windings for 4 poles or 2 poles, and a simple winding structure consisting of two sets of three-phase windings, a two-pole motor and a voltage type inverter with a three-phase commercial power supply 4-pole motor by Can be obtained.
[0089]
According to the next invention of the electric motor, the rotor can be provided with a permanent magnet or a reluctance torque compatible structure, whereby a highly efficient synchronous motor can be obtained.
[0090]
According to the next electric motor invention, the rotor is provided with an induction cage structure, so that the consistency of the electric motor can be maintained when switching from four poles to two poles.
[0091]
According to the next invention of the electric motor, by applying it for driving the compressor of the refrigeration system, the winding structure can be simplified for the operation of the compressor, and the features of high efficiency and energy saving can be sufficiently exhibited. .
[0093]
According to the following motor drive device invention, a three-phase commercial power source is connected to a set of three-phase windings of an electric motor through switching means, and a one-way switching element is connected in reverse parallel to the switching means. The voltage type inverter composed of the rectifier element is connected, and two sets of this switching means and voltage type inverter are provided corresponding to the two sets of three-phase windings of the motor, and all the voltage type inverters are opened while the motor is driven. After that, by closing the opening / closing means and switching to the three-phase commercial power source, it is possible to suitably perform the three-phase and six-phase operation at the time of driving the inverter and to smoothly switch between the inverter driving time and the commercial power source driving time. be able to. In this case, simultaneous switching becomes unnecessary, and surge can be prevented at the time of switching.
[0094]
According to the following motor drive device invention, when driving with a three-phase commercial power source, the opening / closing means is connected so as to be a two-pole motor, and when driving with a voltage-type inverter, a two-pole motor or 4 By controlling the voltage type inverter so as to be a pole motor, it becomes possible to perform three-phase power drive with the voltage type inverter and switching means, and to perform six-phase power source drive with the voltage type inverter. Will also be smooth.
[0095]
According to the following motor drive device invention, when the inverter is driven, it operates as a 4-pole synchronous motor, and when the 3-phase commercial power source is driven, it operates as a 2-pole induction motor. When switching from 4 poles to 2 poles, consistency can be maintained due to the characteristics of the motor.
[0096]
According to the following motor drive device invention, a voltage-type inverter capable of generating a six-phase voltage from two sets of three-phase power supplies determines the PWM timing by comparing the output waveform and the carrier waveform by a program calculation or control circuit. In the case of controlling as a two-pole motor, by using a carrier waveform whose phase is inverted during PWM control of the inverter arm that generates a voltage of the same phase, only using the carrier waveform whose phase is reversed, the three-phase and the six-phase Among them, a three-phase power source can be easily obtained and a two-pole motor can be obtained. In addition, carrier frequency is canceled by canceling the frequency component of the carrier waveform, the noise is reduced by the cancellation effect of PWM switching noise, the leakage current is reduced, the loss such as iron loss is reduced, and the stress of the smoothing capacitor is also suppressed.
[0097]
According to the following motor drive device invention, a voltage-type inverter capable of generating a six-phase voltage from two sets of three-phase power supplies determines the PWM timing by comparing the output waveform and the carrier waveform by a program calculation or control circuit. When controlling as a four-pole motor, the drive signal applied during PWM control of the inverter arm that generates reverse-phase voltage is to replace each signal corresponding to one three-phase power supply between the upper arm and the lower arm. By applying this, it is possible to easily obtain a 6-phase power source by using a carrier waveform having an inverted phase and exchanging drive signals between the upper arm and the lower arm, thereby obtaining a four-pole motor. In addition, carrier frequency is canceled by canceling the frequency component of the carrier waveform, the noise is reduced by the cancellation effect of PWM switching noise, the leakage current is reduced, the loss such as iron loss is reduced, and the stress of the smoothing capacitor is also suppressed.
[0098]
According to the next motor drive device invention, the arms of the voltage type inverter are close to each other and fixed to the same housing, so that the noise component can be canceled due to the reverse phase of the frequency component of the carrier. The effect can be improved, and the effect of canceling the noise component generated between the grounds can be improved by the arms arranged close to each other.
[0099]
According to the next motor drive device invention, the wiring connecting the voltage type inverter and the motor is close to each other, thereby improving the noise component canceling effect due to the reverse phase of the carrier frequency component. Can do.
[0100]
According to the following motor drive device invention, the switching element breakage detecting means is provided in the 6-phase voltage type inverter, the phase where the breakage is detected is always off, and the motor is driven only by controlling the other phases. If the number of short-circuit breakage is 1 or less, a rotating magnetic field is generated by operating the remaining five phases without operating the phase (arm) including the damaged element, and the motor can be controlled to rotate. it can.
[0101]
According to the next invention of the motor drive device, the six-phase voltage type inverter is provided with the restraint operation control means for controlling the outputs of the two sets of the three-phase output inverters so as to cancel the rotating magnetic field with each other. The electric motor does not rotate and only the heat generation effect is obtained, and the residual heat of the electric motor is used as exhaust heat, and the effect of vaporization movement of the refrigerant around the electric motor is obtained by applying it to the refrigerator compressor.
[00102]
According to the following motor drive device invention, by applying to the drive of the compressor of the refrigeration system, the advantage of high efficiency and the matching of the machine speed at the time of inverter drive and commercial power supply drive can be made with a simple configuration. By making it possible, a drive device suitable for the compressor of the refrigeration apparatus could be obtained.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram according to a first embodiment of the present invention;
FIGS. 2A and 2B are a configuration diagram and a connection diagram of a stator of the electric motor according to the first embodiment of the present invention. FIGS.
FIG. 3 is an operating voltage waveform diagram of the two-pole motor according to the first embodiment of the present invention.
FIG. 4 is an operating voltage waveform diagram of the four-pole motor according to the first embodiment of the present invention.
FIG. 5 is a control flowchart according to a second embodiment of the present invention.
FIG. 6 is a waveform diagram for an operating voltage generation method for the two-pole motor according to the first embodiment of the present invention;
FIG. 7 is a waveform diagram for an operating voltage generation method for the four-pole motor according to the first embodiment of the present invention;
FIG. 8 is a structural conceptual diagram according to Embodiment 3 of the present invention;
FIG. 9 is a control flowchart according to a fourth embodiment of the present invention.
FIG. 10 is an electric motor operating voltage waveform diagram and conceptual diagram according to a fifth embodiment of the present invention.
[Explanation of symbols]
1 three-phase power source, 2 electric motor, 3 opening / closing means, 4 rectifying means, 5 DC smoothing capacitor, 6 inverter, 7 stator core.

Claims (14)

The stator includes two sets of three-phase windings that are mechanically and electrically opposed to each other, and six terminals that lead out the connection terminal portions of the three-phase windings of each set ,
Voltages of the same phase are supplied to opposite windings of two sets of three-phase windings by a three-phase commercial power source connected to switching means provided for each set of two sets of three-phase windings. A two-pole motor is constructed by obtaining a three-phase power source,
A voltage-type inverter composed of a single-conducting switching element and an anti-parallel rectifier element is connected in parallel with the opening / closing means, and two sets of three-phase windings are made by a voltage-type inverter supplied with power from a three-phase commercial power source. A four-pole motor is configured by supplying a six-phase power source by supplying voltages of opposite phases to opposite windings of the wires.
An electric motor characterized by that. The electric motor according to claim 1, wherein the rotor is provided with a structure corresponding to a permanent magnet or a reluctance torque. The electric motor according to claim 1, wherein the rotor has an induction cage structure. The electric motor according to any one of claims 1-3, characterized in that applied to drive the compressor of the refrigeration apparatus.   A three-phase commercial power source is connected to a set of three-phase windings of an electric motor through switching means, and a voltage type inverter composed of a one-way switching element and an antiparallel rectifying element is connected in parallel with the switching means. Two sets of this switching means and voltage type inverter are provided corresponding to the two sets of three-phase windings of the motor, all the voltage type inverters are opened while the motor is driven, and then the switching means is closed to close the three-phase commercial power supply. An electric motor drive device characterized by switching to When driving with a three-phase commercial power source, the opening / closing means is connected so as to be a two-pole motor, and when driving with a voltage-type inverter, the voltage-type inverter is controlled so as to be a two-pole motor or a four-pole motor. The motor drive device according to claim 5, wherein the motor drive device is a motor drive device. 7. The motor drive device according to claim 6, wherein when the voltage type inverter is driven, the motor operates as a four-pole synchronous motor, and when the three-phase commercial power source is driven, the motor operates as a two-pole induction motor. A voltage type inverter capable of generating a 6-phase voltage from two sets of 3-phase power supplies adopts a method of determining PWM timing by comparing the output waveform and the carrier waveform by a program calculation or control circuit, and when controlling as a two-pole motor, The motor drive device according to claim 6 or 7, wherein a carrier waveform whose phase is inverted at the time of PWM control of an inverter arm that generates an in-phase voltage is used. A voltage type inverter capable of generating a 6-phase voltage from two sets of 3-phase power supplies has a method of determining PWM timing by comparing the output waveform and the carrier waveform by a program calculation or control circuit, and when controlling as a 4-pole motor, drive signal applied to the PWM control of the inverter arm which generates a voltage of opposite phase is characterized by applying interchanged in the upper arm and the lower arm of each signal of one of the three phase power supply corresponds, according to claim 6 or 8. A driving apparatus for an electric motor according to item 7 . The motor drive device according to claim 8 or 9 , wherein the arms of the voltage type inverter are close to each other and fixed to the same casing. The motor drive device according to claim 8 or 9 , wherein wirings connecting the voltage type inverter and the electric motor are close to each other. A voltage-type inverter 6 phase, the switching element breakage detection means is provided, the detected phase corruption is characterized by driving the motor in only the control of the other phase as an off constantly claim 5-11 The drive device of the electric motor as described in one. 12. The restraint operation control means for controlling the six-phase voltage type inverter so that the outputs of the two sets of three-phase output inverters cancel each other's rotating magnetic field is provided. The drive device of the electric motor described in 1. 14. The electric motor drive device according to claim 5 , wherein the electric motor drive device is applied to drive a compressor of a refrigeration apparatus.

Images