CN102184765B - Saturable reactor - Google Patents

Abstract

The invention relates to a saturable reactor with better performance that can reduce the reactance value of the saturable reactor in a saturated state. It includes: a saturable reactor core; at least one reactance coil and a plurality of DC coils are respectively installed on one side of the saturable reactor core, and a corresponding position corresponding to the saturable reactor core is respectively provided with a The above-mentioned reactance coil and DC coil structure, another reactance coil and another DC coil with the same number of turns constitute a reactance coil pair and a DC coil pair; wherein, the two ends of a reactance coil pair with the same name are respectively used as a saturated reactor AC circuit The AC terminal I and AC terminal II of the AC terminal are connected to each other; each pair of DC coils is centered, and one of the same-named terminals of a pair of DC coils is connected to a different-named terminal, and the remaining same-named terminals and different-named terminals are located as DC terminal I and DC terminal II; two terminals with the same name and two terminals with different names in the remaining pairs of DC coils are respectively connected.

Description

A saturable reactor

technical field

The invention relates to the field of power transmission and transformation in power systems, in particular to a saturated reactor with better performance.

Background technique

With the continuous development of the power system and the continuous increase of power generation capacity, the short circuit current caused by the short circuit of the power system is very large. The short circuit current caused by the short circuit in the power system is very harmful to the power system. Reducing the short-circuit current can enable the circuit breaker to cut off the short-circuit current, reduce the damage of power equipment during short-circuit, and improve the stability of the power system.

In recent years, research on methods and devices for limiting short-circuit current (also known as current limiters) has become a hot topic.

The current limiter is formed by using the saturation characteristic of the saturable reactor core. A group of DC coils are added to the iron core of the saturable reactor. When the power system is operating normally, the DC power supply supplies DC current to the DC coil to deeply saturate the iron core of the saturable reactor. When the iron core of the saturable reactor is deeply saturated, the saturable reactor presents a small reactance; the current limiter connected in series in the transmission line has no effect on the normal transmission. When a short circuit occurs in the power system, the control module cuts off the DC current of the DC coil, and the iron core of the saturable reactor is out of saturation; the saturable reactor presents a large reactance. The saturated reactor connected in series in the transmission line limits the short-circuit current and reduces the short-circuit current.

Patent No. 2008101604501 "a device for limiting short-circuit current of saturable reactor" and patent No. 2008101592788 "device and method for limiting short-circuit current" are one of the research achievements in this regard. The saturable reactor is the core equipment of the saturated reactance current limiter, and it is also the most expensive equipment. Its characteristics directly affect the performance index of the current limiter. The invention patent number is: 2010105840411 "a magnetically saturated reactor" proposes a saturable reactor that can reduce the volume and weight of the saturable reactor under the condition of meeting the performance requirements; in the state of magnetic saturation, it can reduce the reactance value of the saturable reactor A saturable reactor. Further improving the performance of the saturable reactor is still the pursuit of the goal.

Contents of the invention

The purpose of the present invention is to solve the above problems, further reduce the reactance value of the saturable reactor in the state of magnetic saturation, and have strong anti-interference ability.

To achieve the above object, the present invention adopts the following technical solutions:

A saturable reactor comprising:

A saturable reactor core; at least one reactance coil and a plurality of DC coils are respectively installed on one side of the saturable reactor core, and a corresponding position corresponding to the saturable reactor core is respectively provided with a Another reactance coil and another DC coil with the same structure and number of turns as the DC coil form a reactance coil pair and a DC coil pair; among them, the two terminals with the same name of a reactance coil pair are respectively the AC terminals of the AC circuit of the saturated reactor I and AC terminal II, their two opposite ends are connected;

Each pair of DC coils is centered, one of the same-named ends of one pair of DC coils is connected to a different-named end, and the remaining same-named and different-named ends are located as DC terminal I and DC terminal II; the two same-named terminals in the remaining pairs of DC coils The end is connected to the two opposite ends respectively.

A saturable reactor comprising:

A saturable reactor core; one side of the saturable reactor core is respectively equipped with reactance coil L1, DC coil L2, and DC coil L5; the other side of the saturable reactor core is respectively equipped with reactance coil L3, DC coil L4, and DC coil L6; Reactance coil L1 has the same structure and number of turns as reactance coil L3; DC coil L2 has the same structure and number of turns as DC coil L4; DC coil L5 has the same structure and number of turns as DC coil L6;

The end with the same name of the reactance coil L1 is one of the AC terminals I of the AC circuit of the saturated reactor, the opposite end of the reactance coil L1 is connected with the opposite end of the reactance coil L3, and the end of the same name of the reactance coil L3 is the other end of the AC circuit of the saturated reactor One AC terminal II;

The same-named end of the DC coil L2 is connected to the different-named end of the DC coil L4. The different-named end of the DC coil L2 is one of the DC terminals I of the DC circuit of the saturable reactor, and the same-named end of the DC coil L4 is the other of the DC circuit of the saturable reactor. a DC terminal II;

The same-named end of the DC coil L5 is connected to the different-named end of the DC coil L6, and the different-named end of the DC coil L5 is connected to the same-named end of the DC coil L6.

The iron core of the saturable reactor is a Japanese-shaped structure; the cross-sectional areas of the iron cores on both sides are equal; the cross-sectional area of the middle iron core is equal to the sum of the cross-sectional areas of the iron cores on both sides.

The invention provides a saturable reactor structure and connection method for reducing the reactance value of the saturable reactor in a state of magnetic saturation.

The beneficial effect of the invention is: in the state of magnetic saturation, the reactance value of the saturable reactor is lower. The saturable reactor of the present invention is used in a current limiter, and when the power system is in normal conduction operation, the reactance value is reduced by 6% compared with the "a magnetic saturable reactor" of the invention patent number 2010105840411. The interference of the AC circuit to the DC circuit is reduced, and the power electronic devices in the DC circuit are protected.

Description of drawings

Figure 1 shows the structure and connection mode of the saturated reactor;

Among them, 1. AC terminal I, 2. AC terminal II, 3. DC terminal I, 4. DC terminal II, 5. Saturated reactor core.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings.

The structure and connection mode of the saturated reactor are shown in Figure 1. The AC terminal I1 and the AC terminal II2 of the device are connected in series to the AC transmission circuit; the DC terminal I3 and the DC terminal II4 of the device are connected in series to the DC power supply circuit.

Since the end with the same name of the reactance coil L1 is the AC terminal I1 of the AC circuit of the saturated reactor, the opposite end of the reactance coil L1 is connected with the opposite end of the reactance coil L3, and the end of the same name of the reactance coil L3 is the AC terminal of the AC circuit of the saturated reactor II; and because the reactance coil L1 and the reactance coil L3 have the same structure, number of turns, and winding method, the process requirements are the same; therefore, the magnetic flux Φ1 generated in the iron core by the alternating current flowing through the reactance coil L1 is the same as that of the reactance coil L2. The magnetic flux Φ2 generated by the alternating current in the iron core is equal in size and upward, and the alternating magnetic flux is upward on both sides of the Japanese-shaped structure, and passes through the middle iron core of the Japanese-shaped structure to form a closed loop. If the DC current of the DC coil L2 and DC coil L4 of the saturable reactor is zero; the iron core of the saturable reactor is out of saturation, and the reactance of the reactance coil L1 and the reactance coil L3 connected in series in the transmission circuit is very large. The iron core 5 of the saturable reactor is a Japanese-shaped structure; the cross-sectional areas of the iron cores on both sides are equal; the cross-sectional area of the middle iron core is equal to the sum of the cross-sectional areas of the iron cores on both sides.

The same-named end of the DC coil L2 is connected to the different-named end of the DC coil L4. The different-named end of the DC coil L2 is one of the DC terminals I3 of the DC circuit of the saturable reactor, and the same-named end of the DC coil L4 is the DC terminal of the saturable reactor DC circuit. Terminal II4. Reactance coil L1 generates power-frequency magnetic flux in the iron core of the saturable reactor, and the power-frequency magnetic flux generates induced electromotive force in the DC coil L2; reactance coil L3 generates power-frequency magnetic flux in the saturable reactor core, and the power-frequency magnetic flux The induced electromotive force is generated in the DC coil L4; since the DC coil L2 and the DC coil L4 have the same structure, number of turns, and the process requirements of the winding method, the power frequency induced electromotive force of the DC coil L2 and the power frequency induced electromotive force of the DC coil L4 The subtraction is zero, and the AC current of the reactance coil L1 and the reactance coil L3 has no influence on the DC circuit. the

When a DC current flows through the DC coils L3 and L4, the magnetic flux generated by the DC coils L3 and L4 is upward and the other downward, and the DC magnetic flux forms a magnetic flux closed loop in the iron cores on both sides; The AC magnetic flux path of the square-shaped saturated reactor is short, and the iron core is saturated deeply, which has a great influence on the AC coil. Therefore, when the DC magnetic flux saturates the iron core, the iron core column where the AC coil is located is also saturated at the same time. The iron core of the saturable reactor is in a saturated state, and the reactance of the reactance coil L1 and the reactance coil L3 connected in series in the transmission circuit is very small.

The AC coils and DC coils of the saturable reactor are wound on the same iron core column in layers, which strengthens the magnetic coupling between the AC coils and the DC coils.

The same-named end of the DC coil L5 is connected to the different-named end of the DC coil L6, and the different-named end of the DC coil L5 is connected to the same-named end of the DC coil L6. Reactance coil L1 generates power-frequency magnetic flux in the iron core of the saturable reactor, and the power-frequency magnetic flux generates induced electromotive force in the DC coil L5; reactance coil L3 generates power-frequency magnetic flux in the saturable reactor core, and the power-frequency magnetic flux The induced electromotive force is generated in the DC coil L6; since the DC coil L5 and the DC coil L6 have the same structure, number of turns, and the process requirements of the winding method, the power frequency induced electromotive force of the DC coil L5 and the power frequency induced electromotive force of the DC coil L6 The subtraction becomes zero, and no current flows in the DC coil L5 and the DC coil L6. If there is an interfering AC voltage between the DC terminal I3 and the DC terminal II4, the subtraction of the power frequency induced electromotive force of the DC coil L5 and the power frequency induced electromotive force of the DC coil L6 is not zero, and there is a current in the DC coil L5 and the DC coil L6 flow, forcing the interfering AC voltage drop between DC terminal I3 and DC terminal II4. The harm of the interference voltage to the DC circuit is reduced.

The saturable reactor of the present invention can be designed and manufactured by the prior art, and can be completely realized. It has broad application prospects.

Claims (3)

1. saturable reactor is characterized in that it comprises:

A saturable reactor iron core; Said saturable reactor iron core one side is installed at least one reactance coil and a plurality of dc coil respectively; Being respectively equipped with and said reactance coil and dc coil structure, reactance coil and dc coil that the number of turn is identical of saturable reactor iron core opposite side correspondence position symmetry, thereby the formation reactance coil is to right with dc coil; Wherein, two right ends of the same name of reactance coil are respectively ac terminal I and ac terminal II as the saturable reactor ac circuit, and their two different name ends link to each other;

Each is to dc coil centering, and wherein a pair of dc coil end of the same name is connected with a different name end, and remaining end of the same name and different name end are as dc terminal I and dc terminal II; Remain each in the dc coil, two ends of the same name of every pair of dc coil link to each other respectively, and two different name ends also link to each other respectively.

2. saturable reactor as claimed in claim 1 is characterized in that, said saturable reactor iron core one side is installed reactance coil L1, dc coil L2, dc coil L5 respectively; Saturable reactor iron core opposite side is installed reactance coil L3, dc coil L4, dc coil L6 respectively; Reactance coil L1 and reactance coil L3 structure, the number of turn are identical; Dc coil L2 and dc coil L4 structure, the number of turn are identical; Dc coil L5 and dc coil L6 structure, the number of turn are identical;

The end of the same name of reactance coil L1 is one of them ac terminal I of saturable reactor ac circuit, and the different name end of reactance coil L1 is connected with the different name end of reactance coil L3, and the end of the same name of reactance coil L3 is another ac terminal II of saturable reactor ac circuit;

The end of the same name of dc coil L2 is connected with the different name end of dc coil L4, and the different name end of dc coil L2 is one of them dc terminal I of saturable reactor DC loop, and the end of the same name of dc coil L4 is another dc terminal II of saturable reactor DC loop;

The end of the same name of dc coil L5 is connected with the different name end of dc coil L6, and the different name end of dc coil L5 is connected with the end of the same name of dc coil L6.

3. according to claim 1 or claim 2 saturable reactor is characterized in that, said saturable reactor iron core is a day font structure; The sectional area of both sides iron core equates; The sectional area of middle iron core equals the sectional area sum of both sides iron core.

Images