JP3711749B2 - Permanent magnet type synchronous motor and control method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a permanent magnet type synchronous motor and a control method thereof. Permanent magnet synchronous motors have the property that they can only rotate at synchronous speeds. Therefore, it is necessary to detect the phase of the rotor (rotor) and the stator (stator) and determine the timing for exciting the stator winding (coil).
[0002]
[Prior art]
Conventionally, there are two methods for detecting the phase of the rotor and the stator. In the first method, a position detector (rotary encoder, magnetic detection element, etc.) is attached to the rotor to detect the position, and in the second method, induction generated when the rotor rotates. The position is detected by voltage.
[0003]
[Problems to be solved by the invention]
By the way, the method of detecting the position by attaching the position detector to the rotor as in the former requires the position detector, and thus increases the manufacturing cost of the motor and increases the scale of the motor. It will be. In addition, the position detector is deteriorated in reliability or responsiveness in the case of high speed rotation, and the reliability is inferior because the wiring is increased to provide the position detector. In addition, there are various problems that the number of steps for mounting the position detector is increased and the manufacturing process is troublesome.
[0004]
On the other hand, the method of detecting the induced voltage by the rotation of the rotor has the problem that the induced machine cannot be smoothly driven from the stopped state because the induced voltage cannot be detected when the rotor is stopped. Had. Under such circumstances, it has been usual to use an expensive electric motor with a large apparatus scale equipped with a position detector.
[0005]
Accordingly, an object of the present invention is to solve the above-mentioned problems in the conventional technology, and without stopping the sensor for detecting the position of a rotary encoder, a magnetic detection element, etc. Provides a permanent magnet synchronous motor that can detect the phase between the rotor and the stator of the motor, and has high reliability and responsiveness without increasing the manufacturing cost and the equipment scale of the motor, and a control method therefor There is to do.
[0006]
[Means for Solving the Problems]
In order to solve the above technical problems, the first invention is a motor (1) having a rotor using a permanent magnet and a stator provided with a winding, and supply of positive and negative currents to each winding. And the inverter circuit (2) for switching between shut-off and the operation of the electric motor and the determination of when the motor is stopped. During operation, the phase between the rotor and the stator is detected based on the induced voltage induced in each winding, At the time of stopping, the inverter circuit is instructed to shut off after supplying a current for a predetermined time to each winding, and the phase is detected based on the back electromotive voltage generated in the winding after the current is cut off. A constant phase detection control circuit (3) for instructing the inverter circuit to supply or cut off current so as to draw the rotor into an appropriate winding position closest to the rotation according to the phase It is.
[0007]
Here, for phase detection, the current supplied to each winding at the time of stopping is either a positive current or a negative current, and a current having the same waveform is determined in advance in order to facilitate the structure and analysis. It is preferable to supply for a certain period of time.
“Instructing the inverter circuit 2 to supply or cut off current in accordance with the phase” is for rotating the rotor at a synchronous speed or the like during operation, and for stopping the rotor. This is to excite the winding at the winding position closest to the pole, pull the rotor, and start the initial state from a fixed position to increase the rotation frequency and smoothly shift to synchronous speed control.
[0008]
According to the present invention, when the induction voltage (induction voltage) is not detected on the winding and it is determined that the motor is stopped, if there is a command to start the motor 1 from the stopped state, the constant phase detection control means 3 By switching control 2, a positive or negative current is preferably caused to flow in each winding (coil) for a certain period of time. When a current flows through the winding, a magnetic flux is generated in the winding and stored as magnetic energy in the winding. This stored magnetic energy depends on the winding inductance. The inductance of the winding is determined by the total number of magnetic fluxes that are linked when a current flows through the winding, and is determined by the relative positions of the rotor and the stator.
[0009]
When the current is cut off after being supplied, the stored magnetic energy is changed to electric energy, and a counter electromotive voltage is generated in the winding. The stored magnetic energy amount is discharged as it is as an electric energy amount called back electromotive voltage. Therefore, the inductance value of the winding can be indirectly known by detecting the amount of the back electromotive voltage. In addition, the inductance value of the winding has a relationship that varies depending on the phases of the rotor and the stator.
[0010]
Therefore, the phase of the rotor and the stator can be known by measuring the amount of the back electromotive force generated by cutting off the current after supplying current to each winding without directly measuring the inductance value. The present invention uses this principle.
[0011]
As shown in the circuit block diagram of FIG. 1, according to a second aspect, in the first aspect, the constant phase detection control circuit is configured to detect the phase based on an induced voltage induced in each winding of the stator during operation. A phase detection circuit 3a that detects a phase, a phase detection circuit 3b that detects a phase based on a back electromotive voltage when stopped, a determination during operation and a stop, and a start command for the inverter circuit when it stops And a control circuit 3c for instructing current supply to each winding in the case of occurrence of a predetermined time and instructing current supply or interruption based on the phase.
[0012]
In a third aspect based on the second aspect, the constant phase detection control circuit has switching means 35 for switching connection and disconnection between the neutral point of each winding and the ground voltage, and the control circuit includes the switching circuit. The neutral point is connected to the ground voltage by means, and the counter electromotive voltage generated by supplying the currents to the respective windings at the same time for a predetermined time and then shutting off is applied to the stop phase detection circuit.
[0013]
According to the present invention, the switching means is provided, and the neutral point of the winding is switched to the ground voltage by the switching means, so that a current for a predetermined time flows through the windings of each phase all at once. By disconnecting the sex point from the ground voltage, the current can be cut off and the phase can be detected quickly in a short time.
[0014]
In a fourth aspect based on the second aspect, the control circuit of the constant phase detection control circuit supplies the current to each winding in a predetermined time by sequentially shifting the time to the inverter circuit, and then shuts off. The counter electromotive voltages generated in this manner are sequentially applied to the stop phase detection circuit.
[0015]
According to the present invention, the winding of each phase is sequentially controlled to shift the time, and then the current is supplied and then interrupted to generate the counter electromotive voltage by shifting the time. The phase at the time of stop can be detected without using switching means for switching the voltage at the point.
[0016]
In a fifth aspect of the present invention, in an electric motor including a rotor using a permanent magnet and a stator provided with a winding, a step of determining whether or not the electric motor is stopped, and a determination of being stopped. In this case, the current is supplied to each winding for a predetermined time and then shut off, the step of detecting the phase at the stop based on the back electromotive voltage generated for each winding, and the stop based on the phase And a step of controlling the start-up from.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of a permanent magnet type synchronous motor and a control method thereof according to the present invention will be described with reference to the drawings from FIG. 2 to FIG. Further, this embodiment does not limit the present invention unless otherwise specified.
[0018]
2 to 9 show a permanent magnet type synchronous motor system according to the first embodiment. As shown in FIG. 2, the permanent magnet type synchronous motor includes a two-pole rotor (rotor) 14 using a permanent magnet and a stator (stator) provided with three-phase windings 11, 12, and 13. It has an electric motor 10 and an inverter circuit 20 that switches between supply and interruption of positive and negative DC currents to the respective windings of the stator. In order to supply a positive or negative DC current to the inverter circuit 20, a three-phase AC power supply 40, a converter 50 that changes an AC current into a DC current for each phase using a diode or the like, and rectification by the converter 50 And a smoothing capacitor 60 for smoothing the waveform of the generated current.
[0019]
The inverter circuit 20 is provided with six transistors + W, −W, + V, −V, + U, and −U having the same characteristics, a W-phase winding 13, a V-phase winding 12, and a U-phase winding 11. And a switching element for supplying and blocking a positive or negative current, respectively. As shown in FIG. 2, these transistors are provided so as to form a transistor pair in which two emitters are connected to one another, and an output signal is taken out from the connected portion and supplied to the windings 11, 12, and 13 of the electric motor 10. To do. The inverter circuit 20 further includes a drive circuit 25 that outputs an on or off signal to the base of each transistor in response to an instruction.
[0020]
In order to cause each transistor to perform a switching operation at a predetermined period and rotate the rotor 14 at a predetermined synchronization speed, in each transistor pair, an ON signal is supplied to the base of one transistor and an OFF signal is supplied to the other transistor. In addition, after exciting the winding of a certain phase and pulling the rotor 14, an off signal is applied to the base of the one transistor and an on signal is applied to the other transistor to excite the winding in the reverse direction. While the rotor 14 is pulled away from the position, control is performed such that the winding of the next phase pulls the rotor 14 at the synchronous speed.
[0021]
The permanent magnet synchronous motor according to the present embodiment can always detect the phase between the rotor and the winding with respect to the inverter circuit 20 regardless of when it is stopped or operating. A constant phase detection control circuit 30 that can instruct current supply and cutoff timing based on the current is provided.
[0022]
As shown in FIG. 2, in detail, the constant phase detection control circuit 30 detects the induced voltage induced in the stator windings 11, 12, 13 of the electric motor 10 during operation, thereby rotating during operation. A phase detection circuit 31 that detects the phase of the child, a phase detection circuit 32 that detects the phase based on the back electromotive voltage when the motor is stopped, a determination that the motor 10 is operating and stopped, and the inverter circuit 20 On the other hand, when a start command is given at the time of stopping, an instruction to shut off after supplying positive or negative current for a predetermined time (here, for example, t seconds) to each winding, and positive or negative based on the phase And a control circuit 33 for instructing supply or interruption of a negative current.
[0023]
The constant phase detection control circuit 30 further divides the output signal of the inverter circuit 20 to an appropriate voltage value and applies it to each terminal of the phase detection circuit 31 and the stop phase detection circuit 32. And a switching means 35 using a relay or the like that switches connection and disconnection between the neutral point 15 of the winding of each phase and the ground voltage in accordance with an instruction from the control circuit 33.
[0024]
Next, the stop phase detection circuit 32 will be described with reference to FIG.
The stop-time phase detection circuit 32 holds back electromotive voltages from the U-phase, V-phase, and W-phase windings 11, 12, and 13 and outputs them in accordance with signals from the timing circuit 76. , 75w. The stop phase detection circuit 32 detects a maximum or minimum counter electromotive voltage generated when the N or S pole of the rotor 14 and the winding of the stator are closest to each other. A comparison circuit (comparator) 71u that compares the reference voltage (MAX reference voltage) and the minimum reference voltage (MIN reference voltage) with the back electromotive force generated in each winding and outputs a 1 or 0 signal depending on the magnitude of the comparison. , 72u, 71v, 72v, 71w, 72w. Further, the stop phase detection circuit 32 compares the back electromotive voltages generated in the windings of the respective phases, and outputs a 1 or 0 signal according to the magnitude of the comparison circuit 73u, 74u, 73v, 74v, 73w, 74w. Further, the stop-time phase detection circuit 32 detects a stop-time phase based on the signals output from the respective comparison circuits, and outputs a signal corresponding to the corresponding phase in accordance with a signal from the timing circuit 76. 33, and a timing circuit 76 for instructing the output timing to the logic circuit 77 and the hold circuits 75u, 75v, 75w in response to an instruction from the control circuit 33.
[0025]
Subsequently, the operation of the permanent magnet synchronous motor according to the first embodiment will be described with reference to FIGS. 4 to 9.
An induced voltage is generated during the operation in which the permanent magnet synchronous motor is rotating in a free-run state, and therefore the phase can be detected by the phase detection circuit 31 based on the induced voltage.
[0026]
In the stopped state, no induced voltage is generated, so the phase detection circuit 31 cannot detect the phase. When the induced voltage is not detected by the phase detection circuit 31, the control circuit 33 determines that the rotor 14 is in a stopped state. When the control circuit 33 is instructed to start from the outside in the stop state, the control circuit 33 enters a mode for detecting the phase between the rotor 14 and the stator.
[0027]
Next, the phase detection mode of the rotor and the stator at the time of stop will be described.
As shown in FIG. 4, in order to detect the phase between the rotor 14 and the stator at the time of stop, the control circuit 33 uses the W-phase positive current transistor + W of the inverter circuit 20 and the V-phase positive current transistor. Transistor + V and U-phase positive current transistor + U are turned on, W-phase negative current transistor -W, V-phase negative current transistor -V and U-phase negative current transistor -U The drive circuit 25 is instructed to be turned off. At the same time, the control circuit 33 connects the neutral point 15 to the ground voltage by the switching means 35, so that a positive current is simultaneously fixed to each of the U-phase winding 11, the V-phase winding 12 and the W-phase winding 13. Run for time (t seconds). As a result, each of the windings 11, 12, 13 stores magnetic energy depending on the inductance corresponding to the phase of the rotor 14 and the stator. After a certain period of time, the control circuit 33 cuts off the current by switching the transistor from the on state to the off state. Then, the magnetic energy stored in each winding 11, 12, 13 generates a counter electromotive voltage as shown in the lower part of FIG. 4, and this voltage is divided by the voltage dividing circuit 34 for each winding. The voltage is applied to each terminal of the phase detection circuit 32.
[0028]
As shown in FIG. 3, the counter electromotive voltages obtained by dividing the windings of the respective phases are respectively stored in the hold circuits 75u, 75v, and 75w, and are simultaneously compared with each of the comparison circuits 71u, 71v, 71w, 72u, 72v, 72w, 73u, 73v, 73w, 74u, 74v, 74w, and as shown in the respective phase examples of FIGS. 5, 6, and 7, there are various types according to the phases of the rotor 14 and the respective windings. A determination pattern corresponding to the voltage value is input to the logic circuit 77. The logic circuit 77 determines whether the phase is one of the phases shown in Examples 1 to 12 of FIG. 5, FIG. 6 or FIG. 7 according to each judgment pattern as shown in the table of FIG. A corresponding signal is sent to the control circuit 33.
[0029]
Here, for example, when it is indicated that the comparison result of the comparison circuit 71u, the comparison circuit 71v, or the comparison circuit 71w is larger than the MAX reference voltage, whatever the other comparison result is, it is more than the MAX reference voltage. It is determined that the N pole is closest to the winding of the phase in which the large voltage is detected. That is, in the case of the U phase, a signal representing a phase corresponding to Example 1 in FIG. 5, in the case of the V phase, in Example 3 in FIG. 5, and in the case of the W phase, the signal corresponding to Example 5 in FIG. Output from the circuit 77.
[0030]
Similarly, when it is indicated that the comparison result of the comparison circuit 72u, the comparison circuit 72v, and the comparison circuit 72w is smaller than the MIN reference voltage, a voltage smaller than the MIN reference voltage is detected regardless of other comparison results. It is determined that the south pole is closest to the winding of the phase that has been made. That is, in the case of the U phase, it is determined as Example 7 in FIG. 6, in the case of the V phase as Example 9 in FIG. 7, and in the case of the W phase as Example 11 in FIG.
[0031]
In other cases, the U-phase voltage is represented as U, the V-phase voltage is represented as V, and the W-phase voltage is represented as W. For example, in Example 2 of FIG. The voltage is U = V> W. In this case, the output of each comparison circuit is uncertain because the comparison circuits 73u and 74u for the U phase are U = V, respectively NO and NO, and the comparison circuits 73v and 74v are YES, since V> W. NO, comparison circuits 73w and 74w, and W <U, so NO and YES. Since each voltage is neither the maximum voltage nor the minimum voltage, the output results of the comparison circuits 71u, 72u, 71v, 72v, 71w, 72w are also NO, the output result of NO is set to “0”, and the output result of YES When “1” is set to “1”, a determination pattern “000100010” is obtained. Similarly, determination patterns corresponding to the examples of FIGS. 5, 6, and 7 are obtained as shown in the table of FIG. The determination pattern is converted by the logic circuit 77 into a signal of 6-digit phase information indicating the phase at the time of stop, and is sent from the logic circuit 77 to the control circuit 33 in accordance with the signal from the timing circuit 76.
[0032]
In this way, the control circuit 33 enters the start-up mode from the stop based on the detected phase information. Next, the start mode from the stop will be described.
When receiving the phase information from the logic circuit 77, the control circuit 33 performs pulling excitation control based on the phase information. This pulling excitation control is an operation of pulling the rotor position to a predetermined winding position of the stator as an initial state in order to start up the electric motor 10.
[0033]
For example, when the phases of the windings 11, 12, and 13 of the rotor 14 and the stator 16 are detected as shown in FIG. 9A, the position of the rotor 14 is set to a predetermined winding of the stator 16. In order to pull in to the line position, in this example, the control circuit 33 instructs the inverter circuit 20 to excite the S pole in the + U phase and the N pole in the −U phase.
[0034]
When the phases of the rotor 14 and the stator 16 reach the fixed positions as shown in FIG. 9B, a timer switching mode in which the rotation frequency is automatically increased is entered. When the rotational speed increases and the level of the induced voltage from the electric motor 1 becomes high and position detection becomes possible, the switching timing is performed based on the position information detected by the phase detection circuit 31.
[0035]
As described above, in the present embodiment, the counter electromotive voltage can be detected simultaneously for each phase simultaneously by passing currents through the windings 11, 12, and 13 for a certain period of time and then cutting them off. . In particular, when the number of phases increases, the time from the start command to the start of operation is shortened, and the responsiveness is increased.
[0036]
Next, the permanent magnet synchronous motor according to the second embodiment will be described with reference to FIGS. 10 and 11.
The same reference numerals as those in FIGS. 2 to 4 according to the first embodiment denote the same components. As shown in FIG. 10, the constant phase detection control circuit 36 according to the present embodiment is similar to the first embodiment in that the phase detection circuit 31, the stop phase detection circuit 32, and the And a voltage dividing circuit 34. However, unlike the first embodiment, the constant phase detection control circuit 36 is provided with switching means 35 for switching connection and disconnection between the neutral point of each phase winding of the stator and the ground voltage. Not. Therefore, the control circuit 38 is also different from the control circuit 33 according to the first embodiment in that there is no instruction to the switching means 35.
[0037]
Next, the operation of the permanent magnet type synchronous motor according to the present embodiment will be described with reference to FIG.
When the permanent magnet type synchronous motor is rotating in a free-running state, an induced voltage is generated and the phase can be detected by the phase detection circuit 31 as in the first embodiment.
[0038]
When the motor 10 is stopped, no induced voltage is generated, so the phase detection circuit 31 cannot detect the phase. When the induced voltage is not detected by the phase detection circuit 31, the control circuit 38 determines that the control circuit 38 is in a stopped state. When a start command is given to the control circuit 38, a mode for detecting the phase between the rotor 14 and the stator is entered.
[0039]
Next, the phase detection mode of the rotor and the stator at the time of stop will be described.
As shown in FIG. 11, in order to detect the phases of the rotor 14 and the stator at the time of stop, first, the positive current transistor + U, the negative current transistor -W and the transistor -V of the inverter circuit 20 are detected. Only in the ON state, a positive current is passed through the U-phase winding 11 for a certain period of time. As a result, magnetic energy depending on the inductance corresponding to the phase between the rotor 14 and the stator is accumulated in the U-phase winding 11. After a certain period of time, the transistor that is turned on is turned off to cut off the current. Then, the magnetic energy accumulated in the U-phase winding 11 generates a counter electromotive voltage as shown in the lower part of FIG. 11, and this voltage passes through the voltage dividing circuit 34 and the U phase of the stop phase detection circuit 32. Applied to phase terminals.
[0040]
Next, in order to allow a positive current to flow through the V-phase winding, only the positive current transistor + V, the negative current transistor -U, and the transistor -W of the inverter circuit 20 are turned on, so A current is passed through the winding 12 for a certain time. As a result, magnetic energy depending on the inductance determined according to the phase between the rotor 14 and the stator is accumulated in the V-phase winding 12. After a certain period of time, the transistor that is turned on is turned off to cut off the current. Then, the magnetic energy accumulated in the V-phase winding 12 generates a counter electromotive voltage as shown in the second stage below in FIG. 11, and the stop-time phase detection circuit 32 via the voltage dividing circuit 34. Applied to the V-phase terminal.
[0041]
Subsequently, in order to pass a current through the W-phase winding, only the transistor + W, the transistor -U, and the transistor -V are turned on, and a current is passed through the W-phase winding 13 for a certain period of time. Thus, magnetic energy is accumulated in the U-phase winding 13 based on the inductance determined according to the phase between the rotor 14 and the stator. After a certain period of time, the transistor turned on is turned off to cut off the current. Then, the magnetic energy accumulated in the W-phase winding 13 is converted into a counter electromotive voltage as shown in the third stage in the lower part of FIG. Apply to W phase terminal.
[0042]
The counter electromotive voltages input to the stop phase detection circuit 32 are sequentially held in the hold circuits 75u, 75v, and 75w. Finally, in synchronization with the W phase input, each counter electromotive voltage is received when there is a signal from the timing circuit 76. The voltages are input to the comparison circuits 71u, 71v, 71w, 72u, 72v, 72w, 73u, 73v, 73w, 74u, 74v, and 74w, and compared as described in the first embodiment. The signal is input to the circuit 77, and the corresponding phase information is sent to the control circuit 38 by a signal from the timing circuit 76. In this way, the control circuit 38 enters the start-up mode from the stop based on the detected phase information. The start mode from the stop is the same as that described in the first embodiment.
[0043]
As described above, according to the present embodiment, the switching means 35 is not required as compared with the first embodiment, and therefore a conductive wire that connects the neutral point of the motor and the switching means is also required. Therefore, the current can be applied to the winding by the on / off control of the existing transistor, so that the number of parts is small and the structure is relatively simple.
[0044]
These embodiments are specifically described for better understanding of the present invention, and are not intended to limit other embodiments. Therefore, changes can be made without changing the gist of the invention. For example, in the above description, the permanent magnet type synchronous motor has been described. However, the permanent magnet may be replaced with an electromagnet. In the above description, the case of two poles and three phases has been described. However, the present invention is not limited to these, and can be easily applied to other pole numbers and other phase numbers. In addition, the current supplied to detect the phase at the time of stoppage is not limited to the positive current but may be a negative current. The switching element provided in the inverter circuit is not limited to a transistor. Further, the stop phase detection circuit is not limited to the above-described circuit, and may be various. For example, the phase can be specified more finely.
[0045]
【The invention's effect】
As described above, according to the first invention or the fifth invention, even when the rotor is stopped, the currents to the windings are supplied all at once for a predetermined time and then shut off. The counter electromotive voltage can be detected simultaneously for each phase, the phase at the time of stop can be detected based on the generated counter electromotive voltage, and the rotor is rotated according to the detected phase. By moving so as to be drawn into an appropriate winding position such as the position of the winding closest to the pole of the child, it is possible to easily start from the stop. In particular, when the number of phases increases, it is possible to shorten the time from the start of operation to the start of operation and increase the responsiveness.
Therefore, according to the present invention, it is possible to detect the phase at the time of stopping without providing a position detector such as a rotary encoder, a resolver, and a magnetic detection element in the rotor.
For this reason, it is possible to reduce the manufacturing cost of the permanent magnet type synchronous motor and reduce the scale of the apparatus.
[0046]
According to the second invention, the constant phase detection control circuit includes a phase detection circuit during operation and a phase detection circuit during stop. Therefore, since the phase detection during operation can use the existing phase detection circuit, the manufacturing cost can be reduced correspondingly.
[0047]
According to the third aspect of the invention, the constant phase detection control circuit is provided with switching means for switching connection and disconnection between the neutral point of each phase winding and the ground voltage, and supplies current to the windings of each phase all at once. Then, the phase at the time of stoppage is detected based on the back electromotive voltage generated by shutting off. Therefore, when stopping, it is possible to detect the back electromotive force generated by supplying and shutting off currents to the windings of each phase at the same time, so that it is possible to shorten the time from the start command to the start of movement. High responsiveness because it can.
[0048]
According to the fourth aspect of the invention, the constant phase detection control circuit reverses the current generated by interrupting the current supplied to the windings of each phase of the stator by sequentially shifting the time by switching control of the inverter circuit. The phase at the time of stop is detected based on the electromotive voltage. Therefore, by using an existing circuit and supplying current sequentially to the windings of each phase, the phase at the time of stopping can be detected, so the number of parts can be reduced with a simple configuration and the manufacturing cost can be reduced. Can be planned.
[Brief description of the drawings]
FIG. 1 is a circuit block diagram of the present invention.
FIG. 2 is a circuit diagram showing the permanent magnet type synchronous motor according to the first embodiment.
FIG. 3 is a diagram showing a stop phase detection circuit according to the first embodiment;
FIG. 4 is an operation explanatory diagram of the permanent magnet type synchronous motor according to the first embodiment.
FIG. 5 is a phase explanatory diagram of the permanent magnet type synchronous motor according to the first embodiment.
FIG. 6 is a phase explanatory diagram of the permanent magnet type synchronous motor according to the first embodiment.
FIG. 7 is a phase explanatory diagram of the permanent magnet type synchronous motor according to the first embodiment.
FIG. 8 is a diagram showing a determination pattern according to the first embodiment.
FIG. 9 is a drawing explaining the pull-in operation of the permanent magnet type synchronous motor according to the first embodiment.
FIG. 10 is a circuit diagram of a permanent magnet type synchronous motor according to a second embodiment.
FIG. 11 is an operation explanatory diagram of the permanent magnet type synchronous motor according to the second embodiment.
[Explanation of symbols]
1, 10 Electric motor
11, 12, 13 winding
14 Rotor
2, 20 Inverter circuit
+ U, + V, + W, -U, -V, -W transistor
3, 30, 36 Constant phase detection control circuit
3a, 31 phase detection circuit
3b, 32 Stop phase detection circuit
3c, 33, 38 Control circuit
34 Voltage divider circuit
35 switching means
40 3-phase AC power supply
50 Converter circuit
60 Smoothing circuit
71, 72, 73, 74 Comparison circuit (comparator)
75 Hold circuit
76 Timing circuit
77 logic circuit

Claims (5)

Motor having a stator rotor and windings is applied using a permanent magnet (1), an inverter circuit (2) for switching supply and shutoff of the positive and negative current to the windings, during operation of the motor In the operation, the phase between the rotor and the stator is detected based on the induced voltage induced in each winding, and after the current is supplied to each winding in a predetermined time during the stop. instructs the cutoff to the inverter circuits, detecting the phase based on the counter electromotive voltage generated in the windings after the current interruption, it is closest to the poles of the rotor in accordance with the detected phase the supply or interruption of electric current to draw the poles of the rotor to the position of the winding at all times to indicate to the inverter circuits phase detection control circuit (3) and the permanent magnet synchronous motor and having a. The constant phase detection control circuit includes a phase detection circuit for detecting the phase based on the voltage induced on each winding of the stator during operation (3a), detecting a phase based on the counter electromotive voltage at the time of stopping a stop-time phase detector for (3b), the determination of when and during the stop operation, as well, against the said inverter circuits, a predetermined instruction of the current supply time to each winding in case of a start-up command when stopping And a control circuit (3c) for instructing to supply or cut off current based on the phase. The constant phase detection control circuit comprises a switching means (35) for switching the connection and disconnection between the neutral point and the ground voltage of each winding, the control circuit, a ground voltage the neutral point by the switching means and 3. The permanent magnet synchronous motor according to claim 2, wherein the counter electromotive voltage generated by connecting and connecting the windings to each winding for a predetermined time and then shutting off is applied to the phase detection circuit at the time of stop. The control circuit of the always-on phase detection control circuit sequentially shifts the time to the inverter circuit to supply a current to each winding for a predetermined time and then shuts off and generates a counter electromotive voltage sequentially . 3. The permanent magnet type synchronous motor according to claim 2, wherein the permanent magnet type synchronous motor is applied to a phase detection circuit when stopped. And have you the motor rotor and the windings using a permanent magnet is composed of a stator subjected, and determining whether the motor is stopped, when it is determined to be stopped a step of blocking after supply time determined in advance a current to each winding, and detecting the stop-time phase on the basis of the counter electromotive voltage generated in each of the windings, the start from stop based on the phase And a control method for the permanent magnet type synchronous motor.

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