SU1210187A1 - Thyratron motor - Google Patents

Description

one

The invention relates to electrical engineering, in particular, to valve motors (HP) powered from a direct current network, and can be used in automation devices, sound reproducing and recording annajJaType, etc.

The purpose of the invention is to simplify the VD

FIG. 1 shows the electrical circuit of the device; in fig. 2 - timing diagrams of the voltage of the circuit elements, which are given to the work of VD

The VD (Fig. 1) contains a rotor with permanent magnets 1, a stator with a winding 2 connected in a star, pulse amplifiers 3 and 4, forming two channels of amplification, logic device 5, integrators 6 and 7, threshold detectors 8 and 9,

resistors 10 and 1. FIG. 1 and hereinafter, for convenience, a biphase winding PD is considered. The integrators and threshold detectors form two channels of the functional converter 12.

FIG. 2 denotes: and the voltage on the stator windings with neutral commutation depending on time t or the angular coordinates Л, е d (t) and eg (t) - EMF in the stator phases, when the phases are connected to the power supply with voltage and "EMF" shown by the dashed line U (and Ug are the voltages at the outputs of the integrator 7 and 6; and are the trigger voltage of the threshold detectors; Id and Ug are the voltages at the outputs of the threshold detectors 8 and 9.

VD works as follows. As the rotor rotates, an emf is induced in the windings. At any time, one of the phases of the engine through a pulse amplifier of this phase is connected to a power source. Since the sign of the phase emf with respect to the integrator input coincides with the sign of the applied voltage (motor mode), the output state of the threshold detector of this phase remains unchanged. The phase remains connected until the output state of the threshold detector of the disabled phase changes. The change in state does not occur with a delay of the angle Cf J, when the sign of the emf of this phase changes. In the case of an m-phase motor, the switching algorithm is preserved, i.e. connect 187 2

The winding to the power source is performed when the output signal of the threshold detector of this phase changes, and disconnection 5 when it changes in another phase. At the same time, depending on the selected type of switching, at any time, at least one phase must be in the disconnected and at least

10 single phase in connected state.

In the example shown in FIG. 1 case of a two-phase VD at t, (Fig. 2) the sign of the emf of phase ij is negative and therefore the voltage at the output of the integrator 6 remains unchanged (the integrator is in a saturated state) At the time of connecting the phase A to the positive pole of the power source when the voltage at the output of the integrator 7 reaches the trigger level of the threshold detector 9, the integrator 7 is saturated and at the specified interval the voltage at its output does not change. Logical device

25 operates in such a way that, with a positive Ug and a negative ID, phase A is connected to a positive power source, with a negative Uj and a positive U, phase B is connected to the same power source, etc. At time t, the emf of phase B changes sign and when the integrator goes out of saturation, and the voltage at its output changes by 35

at stake

, (t) U ,, (,. (,)

Since the emf in the motor windings

dv /, e--, (2)

where (f is the winding flux linkage with the rotor magnetic field, then the integral value in the expression (1 does not depend on the rotation frequency, but is determined only by the shape of the emf and flux linkage. Therefore, when the integrator time is constant, and the threshold voltage of the threshold detector corresponding to the expression

,

and, y) e.ltMl-Un,

about

The VD operates at a constant switching angle over a wide range of rotational speed variations. If the VD is made with a small inductive resistance of the winding of the core, then this ensures the maximum efficiency of the VD.

3I2I01

When starting the DB, when the EMF of the windings is absent, the output voltages of the threshold detectors have arbitrary signs. In accordance with this state (Fig. 2), one of the windings, 5 for example B, is connected to a negative power source (), and the input of the integrator of this channel is blocked by a large supply voltage source and. The input of the integrator of phase 7 of phase A goes through the resistor 1 1, the voltage U. from the output of the horn detector of its channel, the action of which is the voltage across its

; Output begins to change according to law 15

- t. .

M b-iUcM t. (four)

After time to, determined from (4) at U, (t) Uj, the output voltage of the integrator reaches the value -Up and the sign of the output signal of the integrator 7 is reversed. As a result, phase B is turned off, and phase A is connected to a positive power source. After the time 2ttu., Determined from (1) with ei (t) Uj ,,, the next switching occurs, etc. Great .. "

-HF

h, tue

-tic

l

X

V

5 Yu

15

20

five

874

displacement rank U ;. (2-5 mV) is chosen so that the frequency of switching set in the absence of EMF in the windings does not exceed the frequency of engine response (1-5 Hz). Under the action of currents in the windings, the rotor of the motor is driven into rotational motion, the emf of the de-energized phase, with the correct direction of rotation, contributes to a decrease in the response time, and at the reverse, to its increase. As a result of such an active effect of the EMF, the VD is rapidly switching to the self-switching mode, and with an emf amplitude of 100 mV, the effect of the trigger circuits on the switching angle is almost absent.

Thus, neutral switching is maintained in the VD over a wide range of rotational speed variations, which ensures the highest possible engine efficiency. The connection between the output of the threshold detector and the input of the amplifier of the integrator significantly simplifies the trigger device and thereby reduce the volume of the VD switch.

tM

tM

Have

tM

JW tM

Claims (2)

1.VENTILY MOTOR, containing a rotor with a permanent magnet excitation device, a stator with an armature winding, m phases of which are connected to the power supply circuit through m pulse amplifiers, forming w amplification channels, control circuits of the amplifiers are connected to the output of the logic device, made with the possibility of disconnecting the previous amplification channel when connecting the next, the inputs of the logic circuit are connected with the phases of the armature winding through a functional converter, which includes an integrator and threshold detectors, different In that, in order to simplify the electric motor, an integrator with saturation was used as an integrator, the functional converter is made in the form of channels, each of which contains a saturator integrator and a threshold detector connected in series at the input / output. 2. The electric motor according to π. 1, characterized in that each channel of the functional converter is equipped with a resistor connected between the output of the threshold detector and the inverting input of the integrator. Fi g! SU.,., 1210187> 1,121