SU392590A1 - CLOCKLESS ELECTRIC MOTOR PERMANENT - Google Patents

Description

one

DC-collector electric motors are known, comprising a multiphase winding on a stator, a rotor, a semiconductor switch and a control unit with a ring switch.

In the known electric motors, switching of the switch occurs according to the signals of the rotor position sensor. The presence of the sensor complicates the design of the machine, increases the number of wires, and the approach to the engine.

The proposed motor does not have a special rotor position sensor, and to control the switch uses the effect of changing the inductive phase resistance at high frequency as a function of the angle of rotation of the rotor, for which the ring switch of the switch control unit is made on magnetic amplifiers, the control winding of each of which is included in the switch circuit and the alternating current winding through a high-frequency source and a splitter filter is connected at one end to the corresponding stator phase winding, and the other end to the supporting element, in parallel with which the semiconductor key of the ring switch is connected, and at the input of the latter, the locking delay circuit in the form of an RC chain is turned on.

FIG. 1 shows the electrical circuit of the engine; in fig. 2 shows the curves of the high frequency signal in the phases of the engine as a function of the angle of rotation of the rotor. The engine has a phase winding 1-3 (Fig. 1). High frequency chokes 4–6 and capacitors 7–9 form isolation filters. The power switch is made on cutting diodes 10-12 and thyristors 13-15 with switching capacitors 16-18. The high frequency voltage is supplied through a transformer with output windings 19-21 connected via a high frequency switch on magnetic amplifiers 22-24 to the supporting elements made on diodes 25-27 with parallel-connected transistors 28-30. The current value of the diodes 25-27 is set by the resistances 31-33. A closing delay circuit in the form of a series-connected capacitor (34-36) and resistance (37-39) is connected to the inputs of transistors 28-30.

Brushless electric motor with this control unit operates as follows

in a way. When the engine is turned on, a starting pulse is sent to any thyristor of the power switch from the starting device (not shown in the diagram). One motor phase is switched on, for example /. In doing so, the magnetic amplifier 22 is saturated, the control winding of which is included in the thyristor circuit 13. The rotor of the engine tends to occupy the position when the axes of the magnetizing force of the stator and the rotor coincide. However, when approaching this position at point 2 (Fig. 2), the high-frequency current of the measuring circuit IA of the phase / (Fig. 1) exceeds the value of the current / o (Fig. 2) flowing through the diode 25 (f-ig. 1), and begins to flow through the emitter-to-base transition of the transistor 28, opening it and giving a control pulse to the thyristor 14 of the adjacent phase. It opens, its current saturates the magnetic amplifier 23, the thyristor 13 is extinguished due to the switching capacitor 16. The motor moment is created with the same sign as before, and the rotation takes place in the same direction. At the first moment, after turning on the thyristor 14, the charging current of the non-RC circuit (37, 34) increases the current of diode 26, which prevents false opening of transistor 29. Transistor 29 opens at the approach of the rotor to point 3 (Fig. 2), and the current passes in phase 3; the thyristor 15 will open, and the thyristor M will turn off.

Circular switching of power and control circuits takes place. The maximum torque of the motor corresponds to the minimum of the high-frequency current - points a, b, c (Fig. 2).

To increase the modulation depth of the high-frequency current in the measuring circuit, the high frequency is chosen equal to the resonant frequency of the series series from the separation capacitor 7 and the inductance of the motor phase 1 for the position of the rotor corresponding to the maximum of the high frequency current.

The switching times of the power and high-frequency switches are fixed by the current of the diodes 25-27. The support element here simultaneously performs the functions of a lushness amplifier. The motor speed is controlled by varying the DC voltage or changing the current of the support member by changing the resistances 31-33. A high-frequency switch in the motor circuit is necessary, since when high-frequency voltage is simultaneously applied to all phases of the motor in two phases, the position of the current maxima displaces due to the mismatch of the axis of the resulting magnetizing force of the maschine and the axis of the phase. In the case of economical speed control of the engine, the control unit can be equipped with an additional supporting element having opposite connection with the main supporting element, and the power switch is equipped with an additional key disconnecting the engine from the network connected to the control unit, in this case the phases switching on /, 2 , 3 engines alternate

with the moments when the engine is completely disconnected from the network O (Fig. 2). In order to increase the economy of regulation, the middle of the inter-interval of time, when the phase is switched off, must fall on points a, b, c, when the axis

the phases and the axis of the pole are equally perpendicular. In this case, the motor phases are switched on at moments 1, 3, 5 (Fig. 2) with an additional supporting element, and the engine is disconnected from the network and the high-frequency switch is switched by the main supporting element in MO-cops 2, 4, 6. With this regulation of the power engine the switch and the high-frequency switch are performed separately, since the measuring circuits of the -block

Controls must not be completely disconnected from the engine.

Subject invention

Claims (2)

1. Brushless DC motor containing a multiphase winding on the stator, a rotor, a semiconductor switch for switching the current in the stator depending on the rotor position, and the unit control with ring switch, characterized in that, in order to simplify the design, the ring switch is made on magnetic amplifiers, the control winding of each of which is included in the circuit switch, and the winding of the non-direct current through the high-frequency voltage source and the separation filter is connected at one end to the corresponding phase of the stator winding, and the other to the supporting element, parallel to which is included a semiconductor key ring switch. 2. The direct current motor according to Claim 1, characterized in that an RC delay circuit locking circuit is connected to the input of the semiconductor key of the ring switch. JA Jc L