RU106807U1 - HEADLIGHTER - Google Patents

Abstract

 A high-frequency arrestor containing a power reactor, in parallel with which a first surge suppressor and a tuner with a first capacitor at the input are connected, to which a second surge suppressor is connected through a second capacitor, which shunts the series circuit from the first inductor and the resistor connected in parallel, the second inductor and the third capacitor while parallel to the second capacitor is connected to the third surge suppressor.

Description

The utility model relates to the field of high-frequency communication over wires of power lines used in the energy sector to transmit supervisory control signals, emergency control devices and relay protection of power facilities.

High-frequency chokes (chokes) are connected in series to the wires of power lines (power lines) and must remain operational after exposure to surge waves arising in electrical networks during thunderstorms, switching switching and emergency situations on power lines.

The functionality of the barrage is estimated by the width of its barrage strip.

Known suppressor with a configuration in the form of a parallel resonant circuit, consisting of a power reactor and series-connected capacitor and resistor connected to its terminals, while a surge arrester is used to protect against overvoltages (V. Sapirshtein. Setting up single-part arresters. Operation of communication devices in power systems M., Energy 1966, issue 7, pp. 29-63).

The disadvantages of this trap are the low efficiency of the surge protection device with a steep wave front, since the breakdown voltage of the spark gap of the spark gap is unstable and depends on the rate of rise of voltage on it. With a pre-discharge time of less than 0.1 μs, the breakdown voltage of the spark gap becomes undefined and damage to the trap can occur, for example, in gas-insulated substations.

In another well-known arrestor, in addition to the arresters, an inductance coil is also used in the protection circuit, which delays the voltage rise rate and, as a result, the pre-discharge time of the arrester increases (Mikutsky G.V. High-frequency arresters and connection devices for high-frequency communication channels. Energoizdat. M., 1984 p. 84, Fig. 43). However, this solution degrades the blocking capabilities of the trap and significantly complicates its design due to the need to install a coil and a second spark gap.

The closest technical solution to the claimed (its prototype) is a suppressor using surge arresters (varistors), in which the protective level is practically independent of the surge wave front (RF Patent No. 42918 of 08/12/2004).

However, in the prototype suppressor, there remains the danger of overvoltages in the tuner, which can several times exceed the protective level of the surge suppressor and the electric strength of the capacitor.

The objective of the utility model is to ensure the electric strength of all elements of the tuner during transient conditions under the influence of pulse surges with a steep wave front from the side of the electric network.

The technical result consists in reducing overvoltages on the elements of the suppressor.

The above technical result is achieved in that in a high-frequency suppressor containing a power reactor, in parallel with which a first surge suppressor and a tuner with a first inlet capacitor are connected, to which a second surge suppressor is connected through a second capacitor, which shunts the series circuit from the first inductor and is connected in parallel a resistor, a second inductor and a third capacitor, a third limiter is connected in parallel with the second capacitor overvoltage.

The essence of the utility model is illustrated by the drawing of figure 1, which shows the electrical diagram of the trap.

The suppressor contains a power reactor 1, in parallel with which a first surge arrester (arrester) 2 is connected, and a tuner 3 with a first capacitor 4 at the input, to which, through a second capacitor 5, a second arrester 6 is connected, which shunts the series circuit from the first inductor 7 and is connected in parallel a resistor 8, a second inductor 9 and a third capacitor 10. In parallel with the capacitor 5, a third arrester 11 is connected.

Conclusions 12 and 13 are designed to connect the trap to the power line wire.

The trap works as follows.

High-frequency signals are received from the transmitter via power lines to the terminals 12, 13 and further to the power reactor 1, the first overvoltage limiter 2 and the setting unit 3. The capacitor 4, together with the inductance of the reactor 1 and the capacitor 5 connected to them, an inductor 7 parallel to the RLC circuit, consisting of a resistor 8, an inductor 9 and a capacitor 10, form a complex resonant system with a high input resistance tuned to the frequency of the high-frequency signal. The resistor 8 serves as the load of the resonant system and provides the necessary value of the blocking resistance in the working band of the device for high-frequency signals.

Thus, to block the high-frequency signals of the transmitter, a filter plug is created, which is necessary when organizing the communication channel but the power lines to eliminate the shunting effect of the electrical equipment of the electrical substation.

When surge waves with large amplitudes arrive through the power lines through leads 12 and 13 to power reactor 1, limiter 2 and tuner 3, the charge of capacitors 4, 5 and 10 begins. The voltage rise across capacitor 4 and power reactor 1 stops when it reaches They are the values of the protective level of the limiter 2. Thus, the amplitude of the overvoltage on the capacitor 4 and the power reactor 1 is limited to a safe value for them. The greatest danger of overvoltage is for capacitors.

Next, the transition process continues in the tuner 3, namely in a serial circuit of a capacitor 5, an inductor 7 and a parallel RLC circuit of elements 8, 9, 10.

The transition process acquires an oscillatory or aperiodic character depending on the quality factor of the circuit, because the energy is partially damped by the active resistance of resistor 8. With a high figure of merit of the circuit of the trap, for example, with stripe bands in the low frequency range of its operating range, the transition process is accompanied by a further increase in voltage across the capacitors 5 and 10 due to the influence of the remaining voltage on the limiter 2 and magnetic energy stored in inductors 7 and 9.

With increasing voltage at the nonlinear limiter 6, its resistance decreases, and when it is triggered, the inductor 7 and the parallel RLC circuit are bypassed. As a result, the voltage value on these elements of the tuner is reduced. The limiter 11 reduces the overvoltage on the capacitor 5.

Therefore, the voltage level on all elements of the tuning unit 3 can be reduced to a safe value and thus the reliability of the trap during the transition process under the influence of surge waves arising in electrical networks is significantly increased.

Claims (1)

A high-frequency arrestor containing a power reactor, in parallel with which a first surge suppressor and a tuner with a first capacitor inlet are connected, to which a second surge suppressor is connected through a second capacitor, which shunts the series circuit from the first inductor and the resistor connected in parallel, the second inductor and the third capacitor while parallel to the second capacitor is connected to the third surge suppressor.