SU400029A1 - DC BREAKER - Google Patents

Description

one

The invention relates to the field of contactless switching equipment.

Known DC disconnectors containing a main thyristor and a parallel circuit of quenching and recharging thyristors, a capacitor and throttle connected in parallel do not provide stable operation at low load currents and have a limited range of output power control.

In the proposed chopper, the control electrode of the recharge thyristor is connected to the negative terminal of the power source, and an additional thyristor is sequentially connected between the output power supply terminal and the cathode of the rechargeable thyristor.

This increases reliability and extends the range of output power control.

FIG. Figure 1 shows the printable circuitry of the described chopper; in fig. 2 is a variant with several loads.

The jumper (see Fig. 1) contains the main thyristor 1 in the load circuit 2, the diode 3 being shunted with the inductive nature, the extinguishing thyristor 4 and the capacitor 5 connected in series and parallel to the thyristor 1, the recharge thyristor 6 and the choke 7, interconnected in series and parallel to the capacitor 5.

The control electrode of the recycle thyristor 6 through the resistor 8 is connected to the negative terminal of the power source 9. An additional thyristor 10 is sequentially connected in between the output of the power source and the cathode of the recharge thyristor. In the variant with several loads (see Fig. 2) the latter through the main thyristors 1 is connected to the power source 9 and, through quenching thyristors 4, to the common point of the capacitor 5 and the throttle 7.

The switch shown in FIG. one,

works as follows.

At the same time, the thyristors 4 and 10 are unlocked. The capacitor 5 is charged in two ways: through choke 7 and thyristor 10, as well as through thyristor 4 and load 2. When the voltage across the capacitor becomes equal to

the voltage of the power source, the thyristor 5 is locked, under the action of ed. self-induction load begins to flow a current through the blocking valve. Drossel 7 parameters are chosen so that they are provided

further resonant charge of the capacitor 5 along the circuit: positive terminal of the power source 9, capacitor 5, choke 7, thyristor 10, negative terminal of the power source of polarity indicated in fig. 1 to

voltage higher than the voltage of the power source. When the charge is terminated by the reverse voltage, the thyristor 10 is locked. The discharge of the capacitor along the circuit begins: "plus capacitor 5, power source 9, resistor 8, thyristor control transition 6, choke 7," minus the capacitor. The thyristor 6 is unlocked and a resonant recharge of the capacitor takes place through the thyristor and the choke 7 to a voltage, the floor of which is indicated in FIG. 1 in brackets. Upon completion of the recharge and reverse voltage, the thyristor 6 is locked. Then, the main thyristor 1 is turned on and the load 2 is connected to the power supply. 9. To turn on the main thyristor, the thyristors 4 and 10 are unlocked, the voltage of the capacitor 5 in the closing polarity is applied to the thyristor 1 and turns it off. A new charge occurs on the two chains and the cycle repeats. The adjustment of the average power transmitted to the load is shifted in time. within the cycle time of unlocking the thyristors 4 and 10 according to OT1, the Dissolution at the time of unlocking the main thyristor 1.

When pulsed power control in multiple loads (see Fig. 2), the switch operates in the same way. The main thyristors 1 in the load circuit are unlocked alternately with a fixed shift in time. The extinguished thyristors 4 are also unlocked alternately with an adjustable time shift in relation to the switching points of the main thyristors 1. The thyristor 10 is unlocked simultaneously with the unlocking of each thyristor 4, thereby providing the preparation of a capacitor

to turn off the main thyristor to the next load.

In the described chopper, the thyristor 6, which creates the capacitor recharge circuit, is automatically unlocked upon completion of its charge. Due to this, the time required to prepare the capacitor 5 for locking the main thyristor 1 is shortened, the circuit breaker control circuit is simplified, since

the formation of a control pulse is required to unlock the thyristor 6, shifted in time with respect to the unlocking time of the thyristor 4. Charging the capacitor 5 is not only through the load, but also through the choke 7,

increases the reliability of the breaker at low load currents and significantly reduces the minimum possible off time of the main thyristor, which can be turned on almost immediately after it is turned off.

Subject invention

A direct current interrupter containing a single thyristor and a parallel connected circuit consisting of an extinguishing thyristor, a capacitor and throttle, as well as a recharge thyristor, characterized in that, in order to increase the reliability and extend the range of output power control, the control electrode the recharge thyristor is connected to the negative output of the power supply, and between the power supply output and the cathode of the rechargeable thyristor, respectively, sequentially switch on the additional thyristor.