SU517127A1 - Control unit asynchronous two-phase motor - Google Patents

Description

3

the wanted signal is the voltage of the quadrature component of the UKB, the pulse interference from the key power amplifier, which leads to the input of the Ujjaa device; c) the voltage at the output of the pulse former of the forms; tension on the output of fixer fix; The output voltage of the accumulator Usumm d) the voltage at the output of the comparator UKOMP E) the voltage on the control winding of the Wabm motor; g) current in the control motor winding), vol; h) The current through the key power amplifier The device contains a key power amplifier 1, supplying the motor control winding and a control signal forming circuit consisting of comparator 2, preamplifier 3, top 4, latch 5, former 6 and adder 7.

The control input of latch 5 is connected to the output of pulse generator 6, and the output through amplifier 3 is connected to one input of comparator 2, the other input of which is connected through adder 7 to the outputs of pulse driver 6 and upper 4, and the output to input of power amplifier 1.

The device works as follows. The input voltage that is in phase or out of phase with the reference voltage, i.e. with the mains voltage (Fig. 2a, b) is fed to the input of the latch 5. The pulse shaper 6 generates pulses, connected in phase to the vertices of the reference voltage sine waves (Fig. 2, c)

The pulse shaper is implemented in the form of a phase-shifting chain and a threshold device. At the moments of the postponement of pulses to the control input of latch 5, the latter captures (remembers) the current value of the input voltage. The voltage diagram at the output of fixator 5 is shown in FIG. 2, g.

As can be seen from FIG. 2, bc, the input voltage is memorized at the moments of the extremum® of the harmonic of the useful signal and at the same time the voltage of the quadrature component of the UKB is minimal. The minimum voltage of even higher harmonics (not shown in the diagram) is also minimal. The mean value of the voltage UKB for the time corresponding to the pulse duration is zero.

Thus, the voltage at the output of latch 5 corresponds to the amplitude of the harmonic of the useful signal, regardless of the presence and level of interference from the quadrature component and higher (even) harmonics. Voltage ipf is amplified by amplifier 3 and fed to the input of comparator 2. To the other input of comparator 2, a reference voltage is fed to the output voltage of expander 4 and summed up with the voltage of the pulse driver 6. The voltage diagram at the output of the UcyMM adder is shown in FIG. 2,

As a result of the comparison of the voltages at the inputs of the comparator, at the output of the latter there are 4

pulses whose width is determined by the voltage amplitude ifix and, therefore, by the amplitude of the useful signal (fig. 2, e). Due to the fact that at the largest signal, the voltage at output 5 of amplifier 3 does not exceed the amplitude of voltage of the comparator does not exceed r max. Thus, when the input voltage amplitude changes from zero to maximum 0, the pulse width t at the output of the comparator varies from zero to) where T is the input voltage period (and therefore the network period), t - pulse duration at the output of pulse shaper 5 UKOM 6. The voltage output from the comparator 2 is supplied to the power amplifier 1.

Parallel to the control winding of the motor, a resonant capacitor 8 is turned on. Since the pulses from the comparator output have a mains frequency, 0, they lead to shock excitation circuit 9, 8. As a result, a sinusoidal current with the mains frequency occurs in the control winding. The experimentally derived current and voltage diagrams on the winding are shown in FIG. 2, e-f.

5 The current amplitude in the control winding is determined by the pulse width t at the output of the comparator and varies from zero to t varying from zero to t max. The voltage on the control winding is shifted 0 in phase relative to the mains voltage by 90 °, therefore there is no need to install a phase-shifting capacitor in the excitation winding circuit. From FIG. 2.3 it can be seen that the current through the power amplifier 1 (current consumption) passes only 5 in the presence of a pulse-width signal.

By compensating for the reactive power component by creating a resonance, a high efficiency power amplifier is achieved.

The device is also protected from its own interference, since the voltage from the comparator and the power amplifier 1 induced on the device input is unaval shifted in phase relative to the moments of fixation of the input signal (Fig. 2, b, d).

The coincidence of the moments of fixation and work

the comparator is impossible by limiting the width of the pulses.

When the input voltage phase changes by 180 °, the voltage phase changes accordingly.

Figix, UKOMH and Uo6M- The direction of rotation of the engine changes.

Thus, the circuit provides reverse engine control over a wide range of speeds.

Claims (1)

Invention Formula Control device for a two-phase asynchronous motor, containing a key power amplifier supplying the control winding a motor and a control signal generation circuit consisting of a preamplifier and an amplifier comparator, characterized in that, in order to improve the system noise immunity, a latch, a pulse shaper, and an adder are inserted into the control signal generation circuit; at the same time the manager the latch input is connected to the output of the pulse generator, and the code through the preamplifier is connected to one input of the comparator, the other input of which is connected via an adder to the outputs of the pulse shaping unit and the rectifier, and the output to the input of the key power amplifier.