SU983882A1 - Reactive power compensator - Google Patents

Description

(54) COMPENSATOR OF REACTIVE POWER

 The invention of ognosigs to electrogrog. Inca and can be used to regulate reactive power and electrical networks;

A device is known that allows the reactive power to be regulated by a pug and a laziness of the duration of the switching of condensators into the network I.

The disadvantage of this device is the large weight and dimensions.

The closest to the present invention is a reactive power compensator (CRM), consisting of a main controlled three-phase bridge valve converter, the DC terminals of which are connected in parallel with a choke and a chain of two in series connected switching valves, converter valves and a capacitor connected at one end between the switch valves. This

compensator with power of Nmeg relatively better weight and overall performance 2 J

However, its weight and dimensions are still very high, and the reliability of work is not high enough.

The aim of the invention is to reduce the weight and dimensions and increase

0 reliability KRM in the work.

The goal is achieved by the fact that the CRM, consisting of the main angled three-phase bridge converter, to the terminals of direct current

5 of which are connected in parallel to the throttle and a chain of two according to series-connected switching valves, and the switching valves are turned on opposite to

Claims (2)

The 20 converter valves and a capacitor connected at one end between the switching valves contain an additional three-phase bridge converter, which is connected in parallel to the main three-phase bridge converter in alternating current, and short-circuited on the DC side and connected to the other end of the condenser. FIG. I shows a schematic diagram of the proposed compensator, CRM in FIG. 2 - idealized time diagrams of currents and voltages that explain the operation of the compensator. The I KRM shown in FIG. 1 consists of a main three-phase bridge converter 1, formed from valves 2-7, an additional sin-phase bridge converter 8, formed from valves 9-14, throttles 15, chains from according to series-connected switches 16 to 17, connected to the terminals of the direct current of the main three-phase bridge converter I and the capacitor 18 connected between the common point of the switching valves 16 and 17 and the short-circuited direct current output of the additional three-phase bridge This transducer 8. In FIG. 2 are shown on the axis; 19 phase voltages Ud, Up, U; 2O phase points d in. -TC yrp | at the terminals of the capacitor 18, 22 - the voltage and at the terminals of the throttles 15; Suppose that the valves 2-7 and 9-14 are closed by the time, the current of the throttles 15 are closed through the switching valves 16, 17, and the voltage UK. on the capacitor 18 is equal to its maximum value UKi and negatively, h & lu corresponds to the polarity indicated in FIG. I. Suppose that at time ti (Fig. 2) unlocking pulses are applied to gates 2 and 9, With ego under the action of a voltage LU - (UK (y, -Un.) UCKM- the network voltage between phases A and C at the moment time-b, valve 2 and 9 will open in a closed circuit: capacitor 18, switching commutator, valve 16, valve 2 of phase A and C of the network, valve 9, capacitor 18 generating a switching current, as a result of which the current in the switching valve 16 will drop to zero and it will close, and the current will be closed through valve 2, phase A and C of the network, valve 9, capacitor 18 and switching valve 17, p will start Cutting capacitor 18 and for a period of time Tp will change its voltage from - (JKvyi to + Hz). Over a specified period of time, the network voltage Ug acting on the current circuit will also change, from –I to + UCKH 21. At the time b, unlocking impulse to the switching valve 16. At the same time, under the action of the voltage of the DR (UKWt-Ucvri), the switching valve 16 will open in the above circuit: capacitor 18, switching valve 16, valve 2, phase A and C of the network, valve 9, capacitor 18 arises switching current is of a different direction. As a result, the current in valves 2 and 9 will decrease to zero and they will close and the current will close through the switching: valves 16,17. Similarly, including alternately in operation other bogs of valves 3 and 10, 4 and 11, 5 and 12, .6 and 13, 7 and 14, previously turning off the previous pairs of gates, we obtain a diagram of the change in currents (d, 1 (, generated CRM, shown in FIG. 2, Regulation of the output reactive power in the CRM circuit is performed by changing the ratio of the time interval Tp corresponding to the operation of each of the above pair of valves, to the interval J corresponding to the closed state of all the valves 2 7 and 9-14. out of 20 in each half cycle the current of the CRM phase In the prototype circuit, the phase current in each half-period consists of only one of the specified sections. Therefore, with the same harmonic current generated in the throttle 15 and in all the valves of this scheme are reduced by 3 times, which leads to a decrease in the design power of the throttles of 15. by 43% and the weight and dimensions of the valves by 13%. The efficiency of using the capacitor 18 increases and its installed power decreases by (25-30)%. This is achieved due to the fact that the currents of the threefold and main frequencies are closed along separate circuits. In the known circuit, the capacitor battery is turned off or fails. , leads to a complete violation of the CRM operating mode Such a phenomenon does not occur in the claimed scheme. In addition, in the proposed scheme, at high power, the number of concurrently operating valves decreases when the valve current decreases by a factor of - 3. For these reasons, the reliability of operation of the CRM circuit is significantly increased. Claims of the invention A reactive power compensator consisting of a main controlled gravitational bridge valve converter, to the DC terminals of which are connected in parallel a choke and a chain of two according to sequentially connected switching valves, and the switching valves are switched oppositely from 82-6 the converter, .and capacitor valves, connected by one end between the switching valves, are distinguished by the fact that, in order to reduce the weight and dimensions and higher compensator and reliability in operation, it is provided with additional tre |) also demanded bridge inverter, which is connected to the AC side is parallel to the main three-phase inverter bridge, and on the dc side is shorted-circuited and connected to the other end kondensa1chera. Sources of information taken into account in the examination. 1. Authors certificate of the USSR M 6O5289, cl. H 02 J 3/18, 1973. 2. The patent of Germany No. 1513986, cl. 21 d 42/03, 1965. R  J in G o o city / 21