JPH0534915B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a commutatorless DC motor in which current in a stator winding is commutated by a semiconductor element.

Conventional Structure and Problems Generally, a commutatorless DC motor has a plurality of stator windings, and maintains rotation by commutating the drive current flowing through the stator windings based on a rotational position signal.
The speed control of a non-commutated DC motor is usually carried out by periodically intermittent current flowing through the stator winding.
This was done by equivalently changing the voltage. A typical method thereof will be explained with reference to FIGS. 1 to 3. In FIG. 1, Q ₁ to _{Q 6} are commutator transistors (hereinafter, the description of commutator transistors will be omitted) as commutator control elements.
(called a transistor). The transistors Q ₁ , Q ₃ , and Q ₅ form a first semiconductor element group, and the transistors Q ₂ , Q ₄ , and Q ₆ form a second semiconductor element group. L ₁ ~ _{L 3} are stator windings, D ₁ ~ _{D 6}
is a spike suppression diode. Figure 2 is the first
This is a drive circuit for the circuit shown in the figure. 1 is a rotational position detection circuit, and 2 to 7 are respective rotational position signals.
8 is a signal generating circuit which generates a chopping signal 9; Reference numerals 10 to 12 are AND circuits which perform the logical product of the rotational position signals 2, 4, and 6 and the chopping signal 9, respectively. Base drive signals 13 to 18 drive transistors Q ₁ to Q ₆ , respectively.
Examples of signals of each part in the above configuration will be explained with reference to FIG. For example, in the interval from 0 to π/3, the base drive signals 18 and 13 are at H level, so transistors Q ₆ and Q ₁ are turned on, and the current flows from transistor Q ₁ to stator winding L ₁ to stator winding. L ₃ →
Flows with transistor Q ₆ . Since the base drive signal 13 is stopped here, the current is cut off when the base drive signal 13 becomes L level. Commutation and chopping are repeated in the same manner in the following section from π/3 to 2π. Thus, by changing the time ratio between the H level and L level of the chopping signal 9, that is, the duty,
Equivalently, the voltage applied to the stator windings L ₁ to _{L 3} can be changed, thereby changing the rotational speed of the motor.

The conventional example had the above configuration, so
Even when the transistor on the chopping side is OFF, the transistor on the opposite side is ON, so the base current continues to flow.
This has the drawback of having a loss due to the base current. Another drawback is that the transistor on the chopping side suffers from a large switching loss and is burdened with too much burden.

Purpose of the Invention It is therefore an object of the present invention to reduce the loss due to the base current flowing to the other transistor when switching is OFF, and to apply the switching loss equally to all transistors.

Structure of the Invention In order to achieve this object, the present invention comprises: a rotational position detection means for generating a rotational position signal according to the position of a rotor; a signal generation means for generating a stepping signal; a delay means for generating a delayed chopping signal; a first signal synthesis means for chopping the rotational position signal according to the stepping signal; and a second signal synthesis means for chopping the rotational position signal according to the phase-lag chopping signal. and has
By supplying the output from the first signal synthesizing means to the third terminal of the first semiconductor element group, and supplying the output signal from the second signal synthesizing means to the third terminal of the second semiconductor element group, the first Semiconductor element group is ON/
When turning OFF, the second semiconductor element group is also turned ON/OFF by delaying the phase.

DESCRIPTION OF THE EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings, but components that are the same as those of the prior art will be designated by the same reference numerals and detailed explanations thereof will be omitted.

In the figure, 19 is a position detection circuit which generates position detection signals 20-25. Reference numeral 26 denotes a signal generating circuit which generates a chopping signal 27. Reference numeral 28 denotes a delay circuit to which the stepping signal 27 is input and generates a phase-delayed jumping signal 29.
30 to 35 are AND circuits, and the AND circuits 30, 32, and 34 each receive the position detection signal 2.
0, 22, 24 and the above-mentioned chopping signal 27 are input. Further, the logic circuits 31, 33,
35 are the position detection signals 21, 23, 2, respectively.
5 and the phase delayed chopping signal 29 are input. Outputs 36-41 of the AND circuits 30-35 are transistors _Q1 - _Q6, respectively.
This is the signal that drives the

Next, how each of the signals 36 to 41 is output will be explained with reference to FIG. 6 in terms of behavior between 0 and π/3. Between 0 and π/3, the transistor Q ₆ ,
Position detection signals 25 and 20 are output so that _Q1 is turned ON. Further, signals 41 and 36 are each signal 2
9 and 27, the angle of signal 41 rises from signal 36 as shown in Figure 6.
₁ , a signal is generated that is delayed by a falling angle of ₂ . The same process is repeated for signals 37-40. Since the signals 36 to 41 are moved by the position detection signals 20 to 25, the rotor of the electric motor can be rotated. In addition, the stepping signal 27 and the phase-delayed stepping signal 29
Since the signals 36 to 41 are stepped by , the rotational speed of the rotor can be easily changed by changing the ON/OFF section ratio of the stepping signals. Next, a detailed explanation of the process of jumping will be explained with reference to FIG. Assume that transistor Q ₁ and transistor Q ₆ are now turned on by the position detection signal. At this time, when a signal is sent that turns on the stepping signal 27 and the phase-delayed stepping signal 29, the signals 36 and 41 are output. If the signal 36 turns ON at time t ₀ and turns OFF at time t ₃ as shown in FIG. 7a, the signal 41 turns ON at time t ₁ as shown in FIG. 7b.
It turns ON and turns OFF at time _t3 . Accordingly, the collectors of transistor Q ₁ and transistor Q ₆ =
The emitter voltages V _CE1 and V _CE6 are shown in Figure 7 c and d, respectively.
The waveform will be as shown in . transistor here
Since the collector current I _C of Q ₁ and transistor Q ₆ flows when both transistor Q ₁ and transistor Q ₆ are turned on, it has a waveform as shown in FIG. 7e. The collector losses P _C1 and P _C6 of transistor Q ₁ and transistor Q ₆ are the collector-emitter voltage of transistors Q ₁ and Q ₆ , respectively.
Since it is the product of V _CE1 , V _CE6 and collector current I _C , the waveforms are as shown in FIG. 7f and g. As is clear from this figure, the peak of each collector loss is between time t ₁ and _{t 2} for transistor Q ₁ and between time t ₃ and _{t 4} for transistor Q ₂ , and the losses are distributed almost evenly. . Therefore, in this embodiment, it is possible to reduce the loss due to the base current flowing to the other transistor when stepping is OFF, and to apply the switching loss equally to all transistors.

Effects of the Invention As is clear from the above description, the present invention provides a rotational position detection means for generating a rotational position signal according to the position of the rotor, a signal generation means for generating a stepping signal, and a phase detection means for delaying the phase of the stepping signal. delay means for generating a delayed chopping signal;
a first signal synthesizing means for chopping the rotational position signal in response to the stepping signal; and a second signal synthesizing means for chopping the rotational position signal in response to the phase-delayed chopping signal; By supplying the output from the first signal synthesizing means to the third terminal of the second semiconductor element group and supplying the output signal from the second signal synthesizing means to the third terminal of the second semiconductor element group, the first semiconductor element group
When turning ON/OFF, the second semiconductor element group is also turned ON/OFF with a delay in phase, so when the first semiconductor element group is turned OFF, the second semiconductor element group is also turned OFF with a delay in phase. OFF
Loss due to current flowing through the semiconductor is eliminated,
Moreover, the effect that the burden of switching loss is not applied only to one semiconductor element group but is applied equally to all semiconductor element groups can be obtained.

[Brief explanation of drawings]

Figure 1 is a power circuit diagram of a non-commutated DC motor.
Fig. 2 is a conventional drive circuit diagram, Fig. 3 is an operation diagram of the conventional drive circuit, Fig. 4 is a power circuit diagram of the commutatorless DC motor of the present invention, and Fig. 5 is the drive circuit of Fig. 4. 6 is an operational diagram of FIG. 5, and FIG. 7 is an operational diagram of FIG. 4 during chopping. Q ₁ ...transistor, Q ₂ ...transistor,
Q ₃ ...transistor, Q ₄ ...transistor, Q ₅
...Transistor, Q ₆ ...Transistor, 19
...Rotational position detection circuit (rotational position detection means), 2
6... Signal generation circuit (signal generation means), 28...
Delay circuit (delay means), 30, 32, 34...AND circuit (first signal synthesis means), 31, 33, 3
5...AND circuit (second signal synthesis means).

Claims (1)

[Claims] 1. A DC power source, a rotor consisting of a plurality of permanent magnets, a plurality of stator windings having one end commonly connected and inductively coupled to the rotor, and a rotor according to the position of the rotor. a rotational position detection means for generating a rotational position signal; a signal generation means for generating a stepping signal; a delay means for delaying the phase of the stepping signal and generating a phase-delayed chopping signal; the rotational position detection means; and the signal generation means. a first signal synthesizing means connected to said rotational position detecting means and said delay means for chopping said rotational position signal in accordance with said stepping signal; a second signal synthesizing means for chopping; a first semiconductor element group each having a first terminal connected to the other end of each of the stator windings and a second terminal connected to one end of the DC power supply; a second semiconductor element group having a terminal connected to the other end of the DC power supply and a second terminal connected to each first terminal of the first semiconductor element group; and a first semiconductor element group of each of the first and second semiconductor element groups. a commutator group connected between a first terminal and a second terminal; means for supplying an output signal from the first signal synthesizing means to a third terminal of each of the first semiconductor element groups; and means for supplying an output signal from the second signal synthesizing means to a third terminal of each of the semiconductor element groups.