SU1658274A1 - Device for controlling phase alternation - Google Patents

Description

Yo

Phil

The invention relates to electrical engineering and can be used in electrical installations where, according to the working conditions, a certain order of phase alternation of the three-phase four-wire AC network is necessary.

The aim of the invention is to reduce active power losses.

Fig. 1 is a schematic diagram of the device; Fig. 2 shows time diagrams of voltages and currents explaining the operation of the device.

The device contains the first disk 1 connected by the cathode to phase 2 (A) of the network, resistor 3 and capacitor 4, the outputs of which are combined and connected to phase 5 (8) of the network and to the anodes of the first 1 and second 6 diodes, the actuator 7 connected by the main leads to phases 2 (A), 5 (B), 8 (C) and zero wire 9 of the network. The cathode of the second diode 6 can be connected to the control input of the actuator 7 directly or via the push button 10.

The actuator 7 can be made, for example, in the form of a series-connected three-phase single-wave one rectifier bridge on diodes 11-13, relay 14 and thyristor 15.

The device works as follows.

With direct alternation, the phase voltage across the voltage UNB (Fig. 2a) is ahead in phase of the linear voltage UAB by 30 °, so when you press the button 10 during a period of time, the capacitor 4 is charged by the negative voltage half-period UNB and through the control circuit thyristor electrode 1E - button 10 - diode 6 - capacitor 4 passes a current pulse, including thyristor 15 and relay 14. The relay is disconnected by pressing a button to break the circuit of one of the diodes 11-P, which leads to a decrease in the current through the thyristor to zero after changing the field stress voltage The locking elements and the respective diode bridge rectifying unit into the actuating organ 7

When the order of alternation changes, for example, by changing the phases A and B, the phase voltage UNA (Fig. 26) lags in phase from the linear voltage DBA by 30 °. Therefore, the voltage on the capacitor 4 in the time interval t / j - f exceeds the absolute value of the voltage UNA. The ts-TB operating in the time interval, and when the button 10 is pressed, the unlocking of the diode 6 and the turning on of the thyristor 15 and the relay 14 do not occur. This is due to TfjM, that the voltage on the capacitor 4 is in absolute

the value is greater than the instantaneous value of the voltage UNA.

Thus, in the reverse order of the alternation of the phases of switching the voltage on

electrical installation does not occur. If during the operation the voltage of one or more phases disappears, then the thyristor 15 will also close, and relay 14 will disconnect the voltage from the electrical installation.

The advantage of the proposed device is the possibility of pop-students of large pulse currents, when pressing the button 10 through the relay 14 at the values of the currents through the resistor 3.

reduces the loss of active mass from the device. This is due to the low resistance of the circuit-charge of the capacitor 4 through the elements 5, 10 and 15. The absolute value of the amplitude of the impulse current through the control circuit of the thyristor 15 can be reduced or increased by selecting the capacitor capacitance 4. If necessary, reduce the pulse duration and eio amplitude the capacitor capacitance reduce. Figure 2

the discharge of capacitor 4 ends with direct and reverse phase alternation at times: 1 s.v. ti, poets, stress nz kon gauyure does not affect the duration of the formed uvuiy. ibca current. However, when

required; dimO 1 and the pulse duration can be-. reduced by increasing the resistance of the resistor 3. At the same time, due to the incomplete discharge of the capacitor, the pulse will begin to run when

the phase alternation is not at time t-, a somewhat later, and the pulse duration decreases.

Claims (2)

Invention Formula  i. A device for controlling phase rotation, containing a resistor whose first terminal is connected to the first condens-jTopa terminal. the second terminal of which is connected to the terminal for connection with phase E network, and an actuator connected by main terminals to the terminals for connection with three phases and a neutral wire network, characterized in that. what. in order to reduce active power losses, the first and second diodes are additionally introduced, the anodes of which are combined and connected to the first terminals of the resistor and capacitor, the cathode of the first dmod is connected to the terminals for connecting to the phase And the network, the cathode of the second diode is connected to the control input of the executive grinder, and the second output of the capacitor is combined with the second output of the resistor. 2. The device according to claim 1, about tl and h and ya ee so that. in order to provide short-term control of phase alternation, the cathode of the second diode is connected to the control / the entrance of the executive body through the push button, / / -V Fi.2