JP4222814B2 - Brushless DC motor drive device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a brushless DC motor driving apparatus.
[0002]
[Prior art]
In a brushless DC motor (hereinafter simply referred to as a motor) drive device, when the motor temperature exceeds a reference temperature in order to prevent the motor temperature from rising excessively, the ON period of the switching element of the inverter circuit that drives the motor Has been proposed, and a drive circuit for the motor that prevents the temperature of the motor from rising by suppressing the drive current supplied to the motor has been proposed (Patent Document 1).
[0003]
[Patent Document 1]
JP-A-10-201280 [0004]
[Problems to be solved by the invention]
In the case where the inverter circuit in the motor driving circuit is a single package element, chips constituting the switching element are arranged therein.
[0005]
When energized to drive the motor, depending on the logic to be energized, there may be a location where the temperature rises and a location where the temperature does not rise easily in the package element.
[0006]
In particular, when the motor is in a locked state, there is a possibility of energizing two adjacent switching elements to cause a partial temperature increase. Therefore, not only the circuit configuration for preventing the temperature increase as described above but also the temperature It is necessary to increase the number of detection points for protection or to limit the use capacity.
[0007]
Accordingly, in view of the above problems, the present invention provides a brushless DC motor drive device capable of making the temperature rise distribution of the six switching elements constituting the inverter circuit uniform when the brushless DC motor is energized. .
[0008]
[Means for Solving the Problems]
The invention of claim 1 has an inverter circuit that supplies U-phase, V-phase, and W-phase drive signals Iu, Iv, and Iw to the U-phase, V-phase, and W-phase stator windings of the brushless DC motor, respectively. In the brushless DC motor driving apparatus, the inverter circuit is provided with switching elements Q1, Q2, Q3, Q4, Q5, and Q6, which are transistors or FETs. The switching element Q1 has an emitter terminal or a source terminal and the switching element. A U-phase drive signal Iu is output from the connection point of the collector terminal or drain terminal of the element Q4, and the V-phase drive signal Iu is output from the connection point of the emitter terminal or source terminal of the switching element Q2 and the collector terminal or drain terminal of the switching element Q5. A drive signal Iv is output, and an emitter terminal of the switching element Q3 Alternatively, a W-phase drive signal Iw is output from a connection point between the source terminal and the collector terminal or drain terminal of the switching element Q6, and the collector terminal or drain terminal of each of the switching elements Q1, Q2, and Q3 is connected via a power supply line. Connected to the positive electrode of the DC power supply, and the emitter terminal or source terminal of each of the switching elements Q4, Q5, Q6 is connected to the negative electrode of the DC power supply via a power supply line, and the six switching elements are attached. In the arrangement of the brushless DC motor, the two switching elements adjacent to each other are not energized and the two most distant switching elements are not energized.
[0009]
The invention of claim 2 is characterized in that the six switching elements Q1 to Q6 are arranged in the order of Q1, Q2, Q3, Q6, Q5, Q4. It is.
[0010]
According to a third aspect of the invention, the six switching elements Q1 to Q6 are arranged in the order of Q1, Q3, Q2, Q5, Q6, and Q4. It is.
[0011]
According to a fourth aspect of the invention, the six switching elements Q1 to Q6 are arranged in the order of Q2, Q1, Q3, Q6, Q4, and Q5. It is.
[0012]
The invention of claim 5 is characterized in that the six switching elements Q1 to Q6 are arranged in the order of Q2, Q3, Q1, Q4, Q6, Q5. It is.
[0013]
According to a sixth aspect of the invention, the six switching elements Q1 to Q6 are arranged in the order of Q3, Q1, Q2, Q5, Q4, and Q6. It is.
[0014]
The invention of claim 7 is characterized in that the six switching elements Q1 to Q6 are arranged in the order of Q3, Q2, Q1, Q4, Q5, and Q6. It is.
[0015]
The invention according to claim 8 is the invention according to claim 1, wherein the object to be attached is a wiring board, and the six switching elements Q1 to Q6 are sequentially arranged on the wiring board. It is a drive device of the described brushless DC motor.
[0016]
The invention according to claim 9 is characterized in that the object to be attached is one package element, and the six switching elements Q1 to Q6 are sequentially arranged inside the package element. The brushless direct-current motor drive device according to one of the above.
[0017]
[Operation]
In the brushless DC motor drive device according to claim 1, when energization is performed by energizing the six switching elements constituting the inverter circuit by rectangular wave energization, there is no energization between the two adjacent switching elements. Since there is no energization between two distant switching elements, the distribution of temperature rise can be suppressed uniformly in this inverter circuit.
[0018]
And in order to realize that there is no energization of two adjacent switching elements and no energization of the two most distant switching elements, by using the six arrangements described in claims 1 to 7 Can be realized.
[0019]
According to the brushless DC motor driving apparatus of the eighth aspect, the temperature distribution of one package element can be made uniform.
[0020]
According to the brushless DC motor driving apparatus of the ninth aspect, the temperature distribution of the six switching elements wired on the wiring board can be made uniform.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a driving apparatus 1 for a brushless DC motor (hereinafter simply referred to as a motor) 2 according to an embodiment of the present invention will be described.
[0022]
The motor 2 is used as a drive source for electric tools, fan devices, air conditioners, and the like.
[0023]
(1) Configuration of Driving Device 1 for Motor 2 The configuration of the driving device 1 for the motor 2 will be described with reference to FIG.
[0024]
The motor 2 has three phases, a stator having three stator windings 3, 4, and 5 to which drive signals Iu, Iv, and Iw of U phase, V phase, and W phase are supplied, and a pair of magnetic poles. The rotor 6 which consists of a permanent magnet etc. which has is provided.
[0025]
Further, the motor 2 includes a Hall element or the like for detecting the rotation speed of the rotor 6 and includes a magnetic pole detection element 7 that outputs magnetic pole signals Hu, Hv, and Hw for each phase.
[0026]
The drive device 1 includes an inverter circuit 8, a gate drive circuit 9, a three-phase distribution circuit 10, a PWM circuit 12, a lock detection circuit 15, and a DC power supply 20, and performs bipolar drive by 120 ° rectangular wave energization.
[0027]
The Y-connected stator windings 3, 4, and 5 of the motor 2 are connected to an inverter circuit 8 that supplies U-phase, V-phase, and W-phase drive signals Iu, Iv, and Iw, respectively. The inverter circuit 8 is provided with six transistors Q1, Q2, Q3, Q4, Q5 and Q6. Diodes D1, D2, D3, D4, D5, and D6 are provided in parallel with the transistors Q1 to Q6, respectively. The anodes of the diodes D1 to D6 are connected to the emitter terminals of the transistors Q1 to Q6, and the transistors Q1 to Q6 are connected to the DC power source 20.
[0028]
Each connection of the emitter terminal of the upper transistor Q1, the collector terminal of the lower transistor Q4, the emitter terminal of the upper transistor Q2 and the collector terminal of the lower transistor Q5, the emitter terminal of the upper transistor Q3 and the collector terminal of the lower transistor Q6 From the point, U-phase, V-phase and W-phase drive signals Iu, Iv and Iw are output, respectively.
[0029]
The collector terminals of the upper transistors Q <b> 1 to Q <b> 3 are connected to the positive electrode of the DC power supply 20 through the power supply line 18. The emitter terminals of the lower transistors Q 4 to Q 6 are connected to the negative electrode of the DC power supply 20 through the power supply line 19.
[0030]
The magnetic pole detection element 7 is connected to the three-phase distribution circuit 10. The output of the three-phase distribution circuit 10 is input to the gate drive circuit 9.
[0031]
The gate drive circuit 9 outputs a control signal for turning on / off each of the transistors Q1, Q2, Q3, Q4, Q5, and Q6 to each base terminal.
[0032]
A PWM (pulse width conversion) circuit 12 and a lock detection circuit 15 are connected to the three-phase distribution circuit 10.
[0033]
In the PWM circuit 12, the signal from the speed command input unit 11 is compared with the triangular wave from the triangular wave generation circuit 13 by the comparison circuit 14, and an on-period PWM signal corresponding to a predetermined rotational speed is output to the three-phase distribution circuit 10. The
[0034]
As an example, the lock detection circuit 15 detects the rotational speed of the motor 2 and the detected rotational speed is abnormally low although the drive current is supplied to the stator windings 3, 4, and 5. In some cases, the circuit outputs a lock signal. When the motor 2 is locked, the lock detection circuit 15 outputs a lock signal, and the three-phase distribution circuit 10 outputs a current limit signal based on this lock signal. On the other hand, when the motor 2 is in a normal rotation state that is not locked, the three-phase distribution circuit 10 outputs an energization on signal to the motor 2.
[0035]
Thereby, when the motor 2 is not locked, the gate drive circuit 9 turns on / off the transistors Q1 to Q6 at a timing corresponding to a predetermined rotational speed.
[0036]
Further, when the locked state of the motor 2 is detected, the three-phase distribution circuit 10 shuts off the transistors Q1 to Q6 via the gate drive circuit 9 and stops the rotation of the motor 2.
[0037]
(2) Arrangement Configuration of Six Transistors Q1 to Q6 The six transistors Q1 to Q6 in the inverter circuit 8 described above are sequentially arranged in one package element 22 as shown in FIG. .
[0038]
This package element 22 is electrically connected by soldering to a wiring board (not shown) constituting the gate drive circuit 9, the three-phase distribution circuit 10, the lock detection circuit 15, and the PWM circuit 12.
[0039]
As shown in FIG. 2, the arrangement order of the six transistors Q1 to Q6 in the package element 22 is arranged in the order of Q1, Q2, Q3, Q6, Q5, and Q4 from the left side.
[0040]
(3) Reason for Arrangement of Six Transistors Q1 to Q6 The reason why the six transistors Q1 to Q6 are arranged as described above will be described based on FIGS. 3 to 5 in comparison with the conventional arrangement method.
[0041]
FIG. 3 is a diagram and a table showing a state in which six transistors Q1 to Q6 of this embodiment are arranged, and FIG. 4 is a diagram and a table showing a conventional arrangement.
[0042]
In FIG. 3, as described above, the transistors Q1 to Q6 are arranged in the order of Q1, Q2, Q3, Q6, Q5, and Q4 from the left side. And in this state, in order to rotate the motor 2, 120 degree conducting rectangular wave drive is performed. The six energization patterns 1 to 6 are shown in the lower table of FIG. In this table, the energized transistors are indicated by hatching.
[0043]
For example, no. 3 will be described based on the circuit diagram of FIG.
[0044]
The current flowing through the transistor Q2 flows as Iv in the V-phase stator winding, passes through the middle point as Iu current in the U-phase stator winding, and flows into the transistor Q4.
[0045]
In this case, No. in the table below FIG. As shown in FIG. 3, the transistors Q2 and Q4 are energized to generate heat. However, the transistors Q2 and Q4 are not adjacent to each other and are not the most distant transistors.
[0046]
And No. 1 to No. 6, the two transistors that generate heat when energized are not adjacent to each other as shown in the lower table of FIG. 3, and are not the most distant transistors. The heat generation state in each of the transistors Q1 to Q6 is uniform, and the temperature distribution in the package element 22 is uniform.
[0047]
On the other hand, an arrangement pattern of the conventional transistors Q1 to Q6 in FIG. 4 will be described.
[0048]
The arrangement pattern of the transistors Q1 to Q6 in the conventional example is arranged in the order of Q1, Q2, Q3, Q4, Q5, and Q6 from the left side.
[0049]
Therefore, when the motor 2 is energized, as shown in the lower table of FIG. In the energized state of 3, ie, the energized state in FIG. 5, the adjacent transistors Q2 and Q3 are energized to generate heat, and the temperature rises in the vicinity thereof. No. The same applies to 6. No. In FIG. 2, since the two most distant transistors Q1 and Q6 generate heat, the central portion Q2 to Q5 does not generate heat and does not have a uniform temperature distribution.
[0050]
Therefore, the conventional arrangement pattern has a problem that the temperature distribution in one package element 22 is non-uniform, and the temperature rise portion becomes large.
[0051]
However, as described above, in this embodiment, such a non-uniform temperature distribution does not occur, and the temperature does not rise only in part.
[0052]
Therefore, there is no need to increase the number of detection points for temperature protection or limit the use capability.
[0053]
(4) Other arrangement method The arrangement method satisfying the condition that the two adjacent transistors which are the object of the present invention are not energized and the two most distant transistors are not energized is the first of the above embodiments. In addition to the arrangement method, there are the following five methods.
[0054]
The second arrangement method is arranged in the order of Q1, Q3, Q2, Q5, Q6, and Q4.
[0055]
The third arrangement pattern is arranged in the order of Q2, Q1, Q3, Q6, Q4, and Q5.
[0056]
The fourth arrangement pattern is arranged in the order of Q2, Q3, Q1, Q4, Q6, and Q5.
[0057]
The fifth arrangement pattern is arranged in the order of Q3, Q1, Q2, Q5, Q4, and Q6.
[0058]
The sixth arrangement pattern is arranged in the order of Q3, Q2, Q1, Q4, Q5, and Q6.
[0059]
Although the six arrangement patterns have been described in order from the left, they may be arranged in the above order from the right.
[0060]
(Modification 1)
In the above embodiment, the case where six transistors Q1 to Q6 are arranged in one package element 22 has been described, but instead of this, six transistors Q1 are arranged on the wiring board 24 as shown in FIG. Also in the case of arranging ~ Q6, if the same arrangement pattern as described above is taken, the temperature distribution of the wiring board 24 becomes uniform.
[0061]
(Modification 2)
In the above embodiment, a transistor having a base terminal, a collector terminal, and an emitter terminal has been described, but instead of this, an inverter circuit 8 using an FET having a gate terminal, a source terminal, and a drain terminal may be used. In FIG. 6, illustration of wiring of other components is omitted.
[0062]
【The invention's effect】
As described above, the brushless DC motor driving apparatus according to the present invention can uniformly suppress the temperature rise distribution of the six switching elements, thereby obtaining the effect of reducing the temperature protection detection position of the brushless DC motor. And cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a circuit diagram of a driving apparatus showing an embodiment of the present invention.
FIG. 2 is a front view of a state in which six transistors are built in one package element.
FIG. 3 is a diagram showing an arrangement pattern of six transistors and an energization pattern in the present embodiment.
FIG. 4 is a diagram illustrating an arrangement pattern and energization patterns of six transistors according to a conventional example.
5 is a diagram showing No. 2 in FIG. 3 and FIG. FIG. 6 is a circuit diagram showing a state of an inverter circuit 8 in a current conduction pattern 3.
6 is a plan view of a wiring board according to Modification 1. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Drive device 2 Motor 3-5 Stator winding 8 Inverter circuit 20 DC power supply Q1-Q6 Transistor

Claims (9)

In a brushless DC motor drive device having an inverter circuit for supplying U-phase, V-phase and W-phase drive signals Iu, Iv and Iw to U-phase, V-phase and W-phase stator windings of a brushless DC motor, respectively ,
The inverter circuit is provided with switching elements Q1, Q2, Q3, Q4, Q5, Q6 which are six transistors or FETs,
A U-phase drive signal Iu is output from a connection point between the emitter terminal or source terminal of the switching element Q1 and the collector terminal or drain terminal of the switching element Q4.
A V-phase drive signal Iv is output from a connection point between the emitter terminal or source terminal of the switching element Q2 and the collector terminal or drain terminal of the switching element Q5;
A W-phase drive signal Iw is output from a connection point between the emitter terminal or source terminal of the switching element Q3 and the collector terminal or drain terminal of the switching element Q6.
The collector terminal or drain terminal of each of the switching elements Q1, Q2, Q3 is connected to the positive electrode of a DC power supply via a power supply line,
The emitter terminal or the source terminal of each of the switching elements Q4, Q5, Q6 is connected to the negative electrode of the DC power supply via a power supply line,
When arranging the six switching elements on the attachment object, the two switching elements adjacent to each other are not energized, and the two most distant switching elements are not energized. Brushless DC motor drive device. 2. The brushless DC motor driving apparatus according to claim 1, wherein the six switching elements Q1 to Q6 are arranged in the order of Q1, Q2, Q3, Q6, Q5, and Q4. 2. The brushless DC motor driving apparatus according to claim 1, wherein the six switching elements Q1 to Q6 are arranged in the order of Q1, Q3, Q2, Q5, Q6, and Q4. The driving device for a brushless DC motor according to claim 1, wherein the six switching elements Q1 to Q6 are arranged in the order of Q2, Q1, Q3, Q6, Q4, and Q5. The driving device for a brushless DC motor according to claim 1, wherein the six switching elements Q1 to Q6 are arranged in the order of Q2, Q3, Q1, Q4, Q6, and Q5. 2. The brushless DC motor driving apparatus according to claim 1, wherein the six switching elements Q1 to Q6 are arranged in the order of Q3, Q1, Q2, Q5, Q4, and Q6. 2. The brushless DC motor driving apparatus according to claim 1, wherein the six switching elements Q1 to Q6 are arranged in the order of Q3, Q2, Q1, Q4, Q5, and Q6. The mounting object is a wiring board;
8. The brushless DC motor driving apparatus according to claim 1, wherein the six switching elements Q <b> 1 to Q <b> 6 are sequentially arranged on the wiring board. 9. The mounting object is a single package element;
8. The brushless DC motor driving apparatus according to claim 1, wherein the six switching elements Q1 to Q6 are sequentially arranged inside the package element.

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