WO2016180219A1

WO2016180219A1 - Saturated reactor for shortening transient response time

Info

Publication number: WO2016180219A1
Application number: PCT/CN2016/080092
Authority: WO
Inventors: 李晓明
Original assignee: 李晓明
Priority date: 2015-05-12
Filing date: 2016-04-23
Publication date: 2016-11-17
Also published as: CN104795202B; CN104795202A

Abstract

A saturated reactor for shortening transient response time, comprising a closed-loop iron core (3), wherein there are coils L1, L3 and L5 on one iron core column, and there are coils L2, L4 and L6 on the other iron core column; dotted ends of the coils L1 and L2 are connected to a terminal I (1); a non-dotted end of the coil L1 is connected to a dotted end of the coil L4; a non-dotted end of the coil L2 is connected to a dotted end of the coil L3; non-dotted ends of the coils L3 and L4 are connected to a terminal II (2); a dotted end of the coil L5 is connected to the dotted end of the coil L3; a dotted end of the coil L6 is connected to the dotted end of the coil L4; non-dotted ends of the coils L5 and L6 are connected to the terminal II (2) respectively via a forward thyristor D1 and a reverse thyristor D2; control terminals of the thyristors D1 and D2 are respectively connected to a control circuit (4); and the control circuit (4) controls the size of a firing angle of the thyristors D1 and D2, so as to continuously adjust the magnitude of the rectification amount of the thyristors D1 and D2, and a diode D3 is further connected between the non-dotted end of the coil L1 and the non-dotted end of the coil L2.

Description

Saturated reactor for shortening transient response time

Technical field

The invention relates to the technical field of power system transmission and transformation, and particularly relates to a saturable reactor for shortening transient response time.

Background technique

Reactors are widely used in power systems. The series reactor can limit the short-circuit current; the shunt reactor can limit the over-voltage; the reactor and the capacitor can form a filter circuit. In some applications, the reactance of the reactor is fixed; in some applications, the reactance of the reactor should be constantly adjusted as the operating mode of the power system changes. A controllable saturable reactor (also called a saturable reactor, a magnetron reactor) whose reactance value can be continuously adjusted is an important research subject.

The saturable reactor uses the saturation characteristics of the closed-loop iron core of the saturable reactor to change the reactance of the reactor. A number of saturated reactors have been proposed. China Water Resources and Hydropower Press published in 2008, Cai Xuansan, Gao Yueong, "The Principle, Design and Application of Controllable Saturated Reactors" summarizes the saturable reactors. CN201410714156.6 A fast-reacting DC-saturated reactor improves the transient response time of a saturable reactor. How to further shorten the transient response time of existing saturable reactors is still an important research topic and research direction.

CN201410714156.6 A fast-reacting DC-saturated reactor adopts a series resistance of a saturated reactor circuit to shorten the transient response time of the saturable reactor. The resistors are connected in series in the circuit, which consumes energy, generates heat, and requires heat dissipation. Therefore, it is meaningful to shorten the transient response time of the saturable reactor without using a resistor.

Summary of the invention

SUMMARY OF THE INVENTION An object of the present invention is to provide a saturable reactor which does not require an increase in resistance and which can shorten a transient response time in order to solve the above problems.

To achieve the above object, the present invention adopts the following methods:

A saturable reactor for shortening transient response time, which is single-phase, including a closed-loop iron core of a saturated reactor, coils mounted on two iron cores of a closed-loop iron core, thyristors connected to each coil, and control Thyristor control circuit;

There are three coils on each of the iron core columns, and the number of turns of the three coils is different, but the number of turns of the coils at the same position on the two iron core columns is the same;

The opposite end of the coil at the first position on one of the core legs is connected to the end of the same name of the coil at the second position on the other core post;

The same name end of the coil of the third position on one of the iron core columns is connected to the same end of the coil of the second position of the iron core column;

The different names of the coils at the third position on each iron core column are respectively connected with a thyristor, and the control end of the thyristor is connected with the control circuit, and the control circuit controls the magnitude of the firing angle of the thyristor to continuously adjust the magnitude of the thyristor rectification amount;

The transient response of the coil at the first position on the same core column and the coil at the third position are opposite, offsetting most of the transient response time, resulting in a shortened overall transient response time of the saturable reactor.

Another technical solution of the present invention is a saturable reactor for shortening transient response time, which is a single-phase, including a closed-loop iron core of a saturated reactor, and is mounted on two iron core columns of a closed-loop iron core. a coil, a thyristor connected to each coil, and a control circuit for controlling the thyristor;

The same name end of the coil of the third position on one of the iron core columns is connected to the opposite end of the coil of the first position of the iron core column;

The different names of the coils at the third position on each iron core column are respectively connected with a thyristor, and the control end of the thyristor is connected with the control circuit, and the control circuit controls the magnitude of the firing angle of the thyristor to continuously adjust the magnitude of the thyristor rectification amount.

Further, in the above two aspects, a diode is connected between the different end of the first position coil and the end of the second position coil of the second position coil.

Further, the diode has a parallel resistance across the diode.

Further, in the above two solutions, the two coils and the diode in the first position on the two core legs are used as the harmonic rectification path when the control circuit controls the trigger angle of the thyristor;

When the power frequency flux in the two iron core columns is unbalanced, the diode provides a half-wave rectified excitation current to balance the power frequency flux in the two iron core columns.

Further, in the above two solutions, when the thyristor is fully turned off, the saturated reactor has a maximum reactance value, and an alternating voltage is applied across the thyristor;

When the thyristor is fully turned on, the saturable reactor has a minimum reactance value, and the thyristor constitutes a half-wave rectifying circuit.

Further, when the thyristor is turned on, the two core legs generate DC magnetic fluxes of opposite directions.

Further, in the above two aspects, the two core legs have the same cross-sectional area, and each of them can form at least one magnetic flux closed loop that does not pass through the opposite core leg.

Further, in the above two aspects, the closed-loop iron core is two closed-loop iron cores having no passages with each other or an integrated closed-loop iron core with mutual passage.

Another extension of the present invention is a three-phase saturable reactor, which is a three-phase shortened transient response time saturation reactance of a single-phase short-acting response time-saturated saturable reactor using any of the above two solutions. Device.

The invention has the beneficial effects that the transient response time of the saturable reactor can be shortened without increasing the resistance; The number of turns of the DC coils connected in series is small, which can shorten the transient response time. Moreover, the transient response of the two coils on the same core column of the first type of saturation reactor with shortened transient response time is opposite, offsetting most of the transient response time, so that the transient response time of the saturable reactor is very short. Two kinds of circuits for shortening the transient response time of the saturable reactor are simple.

DRAWINGS

Figure 1 shows a saturable reactor with reduced transient response time.

Figure 2 shows another saturable reactor that shortens the transient response time.

Among them, 1. Terminal I, 2. Terminal II, 3. Closed-loop iron core, 4. Control circuit.

detailed description

The invention will be further described below in conjunction with the drawings and embodiments.

Example 1:

A structure and connection method of a saturable reactor for shortening the transient response time is shown in FIG. It includes a terminal I1, a terminal II2, a closed reactor core 3 of a saturable reactor, and a control circuit 4. The closed-loop iron core 3 of the saturable reactor has at least two iron core columns having the same cross-sectional area and coils; each of the two iron core columns can form a magnetic flux closed loop which does not pass through the opposite core column.

The closed-loop iron core 3 may be two closed-loop iron cores having no passages to each other, for example, 1: two square-shaped iron cores. It can also be a one-piece, closed-loop iron core with a mutual passage; for example, 2: three iron core columns, and a yoke at both ends of the iron core column is connected with three iron core columns, and any two iron core columns can form a magnetic flux closed loop with each other. However, at least two of them can form a closed loop that does not pass through the other core column. For example, 3: four iron core columns, the core legs have yokes connected to the four iron core columns at both ends, and any two iron core columns can form a magnetic flux closed loop, but at least two can form each other without passing through the opposite iron core. The closed loop of the stem is shown in Figure 1.

In the closed-loop iron core 3, two iron core columns having the same cross-sectional area, one of the iron core columns has a coil L1, a coil L3, and a coil L5; the other iron core column has a coil L2, a coil L4, and a coil L6; The number of turns of the coil L1 and the coil L2 is equal; the number of turns of the coil L3 and the coil L4 is equal; the number of turns of the coil L5 and the coil L6 is equal; the number of turns of the coil L1 and the coil L5 is not equal; the number of turns of the coil L3 and the coil L5 is not equal. The same name end of the coil L1 and the coil L2 is connected to the terminal I1, the different end of the coil L1 is connected to the same end of the coil L4, the different end of the coil L2 is connected to the same end of the coil L3, and the different end of the coil L3 and the coil L4 is connected to the terminal II2. The same name end of the coil L5 is connected to the same name end of the coil L3, the same name end of the coil L6 is connected to the same name end of the coil L4, and the different names of the coil L5 and the coil L6 are respectively connected to the terminal II2 via the forward thyristor D1 and the reverse thyristor D2; the thyristor D1, the control terminals of the thyristor D2 are respectively connected to the control circuit 4.

The control circuit 4 controls the magnitude of the firing angle of the thyristor D1 and the thyristor D2 to continuously adjust the magnitude of the rectification of the thyristor D1 and the thyristor D2.

A saturable reactor with a shortened transient response time is rated at U1. Saturated electric power for shortening transient response time The resistor is connected to the power system with the rated voltage of U1. When the control circuit 4 controls the thyristor D1 and the thyristor D2 to be completely cut off, the rectifier circuit of the thyristor D1 and the thyristor D2 does not work, and the coil L1, the coil L2, the coil L3, and the coil L4 flow through. It is a small excitation current. The saturable reactor has a maximum reactance value Zmax.

The coil L1, the coil L2, the coil L3, and the coil L4 have an exciting current, and an induced voltage is generated in the coil L1, the coil L2, the coil L3, the coil L4, the coil L5, and the coil L6. Since the number of turns of the coil L1 and the coil L2 is equal, the number of turns of the coil L3 and the coil L4 is equal, the number of turns of the coil L5 and the coil L6 is equal, and the number of turns of the coil L3 and the coil L5 is not equal; the ends of the thyristor D1 and the thyristor D2 are There is an AC voltage to provide AC power to the thyristor D1 and thyristor D2 rectifier circuits.

When the control circuit 4 controls the thyristor D1 and the thyristor D2 to be fully turned on, the thyristor D1 and the thyristor D2 become diode characteristics, and the thyristor D1 and the thyristor D2 constitute a half-wave rectifying circuit, respectively. The DC current of the coil L1, the coil L2, the coil L5, and the coil L6 reaches a maximum design value. The direct current in the coil L2 and the coil L5 is directed downward, and the direct current in the coil L1 and the coil L6 is directed upward. The coil L1 and the coil L5 are on the same core leg. If the number of turns of the coil L1 and the coil L5 is equal, the magnetic potential generated by the coil L1 in the iron core column and the magnetic potential generated by the coil L5 in the iron core column are equal in magnitude and direction. Instead, the resultant magnetic potential generated in the core column is equal to zero. Similarly, the coil L2 and the coil L6 are on the same core leg. If the number of turns of the coil L2 and the coil L6 is equal, the resultant magnetic potential generated in the core post is equal to zero.

Since the number of turns of the coil L1 and the coil L5 is not equal, the number of turns of the coil L1 and the coil L2 is equal, and the number of turns of the coil L5 and the coil L6 is equal; the resultant magnetic potential generated in the two core columns is not equal to zero, and one iron The DC flux in the stem is facing upwards and the DC flux in the other leg is facing down. The greater the degree to which the number of turns of the coil L1 and the coil L5 are not equal, the larger the DC magnetic flux in the core post. The larger the DC flux in the core column, the larger the AC reactive current of the saturable reactor and the smaller the reactance value of the saturable reactor. According to the design requirements, when the control circuit 4 controls the thyristor D1 and the thyristor D2 to be fully turned on, the saturable reactor has a minimum reactance value Zmin.

The control circuit 4 controls the magnitude of the rectification of the thyristor D1 and the thyristor D2, and can control the magnitude of the direct current in the coil L1, the coil L2, the coil L5, and the coil L6 to control the magnitude of the reactance of the saturable reactor. The control circuit 4 continuously controls the magnitude of the rectification of the thyristor D1 and the thyristor D2, and can continuously control the magnitude of the direct current in the coil L1, the coil L2, the coil L5, and the coil L6, thereby realizing the continuous adjustment of the reactance value of the saturated reactor, and the reactance value of the saturated reactor Adjust and change between the maximum and minimum values.

Further, a diode D3 is further connected between the different end of the coil L1 and the different end of the coil L2. The coil L1 and the coil L3 are wound on the same core leg, and the coil L2 and the coil L4 are wound on the same core leg; since the number of turns of the coil L1 and the coil L2 are equal, the number of turns of the coil L3 and the coil L4 is equal, so the coil L1 and The power frequency (fundamental) potentials at both ends of the coil L2 are equal, and the power frequency (fundamental) potential at both ends of the diode D3 is equal. If the power frequency (fundamental) flux in the two core legs where the coil L1 and the coil L2 are located is unbalanced, the diode D3 only needs to provide a half-wave rectified excitation current to balance the power frequency in the two iron core columns. Wave) flux.

When the control circuit 4 controls the magnitude of the firing angle of the thyristor D1 and the thyristor D2, the current in the coil L1 and the coil L2 contains higher harmonics, and the higher harmonics generate higher harmonic voltages on the coil L1 and the coil L2. A higher harmonic voltage will be generated across diode D3. Experiments show that the coil L1, the coil L2, and the diode D3 form a higher harmonic rectification path to improve the characteristics of the saturable reactor.

CN201410714156.6 In a fast-responding DC-saturated reactor, the number of turns of the two DC coils connected in series with the two thyristors is relatively large, and the number of turns required for the rated voltage is close. In this embodiment, the number of turns of the DC coil L5 and the DC coil L6 connected in series with the thyristor D1 and the thyristor D2 is small, which is approximately equal to the number of turns required for the 1/2 rated voltage. The number of coil turns is small, which shortens the transient response time.

Experiments have shown that the direct current in the coil L2 and the coil L5 is directed downward, and the direct current in the coil L1 and the coil L6 is directed upward. The coil L1 and the coil L5 are on the same core leg, and the transient response tendency of the coil L1 is opposite to the transient response tendency of the coil L5, causing a collision, which can offset most of the transient response time. The coil L2 and the coil L6 are on the same core leg, and the transient response tendency of the coil L2 is opposite to the transient response tendency of the coil L6, and a collision occurs, which can offset most of the transient response time. The overall transient response time of the saturable reactor is very short.

In some applications, diode D3 can be removed to simplify the structure. In some applications, a resistor is placed across diode D3 to reduce the reverse voltage of diode D3.

A saturable reactor for shortening the transient response time shown in FIG. 1 is a single-phase saturable reactor. Single-phase saturable reactors can be extended to three-phase saturable reactors. The promotion method is public knowledge and is no longer cumbersome.

Example 2:

Another structure and connection method of the saturable reactor that shortens the transient response time is shown in Fig. 2. It includes a terminal I1, a terminal II2, a closed reactor core 3 of a saturable reactor, and a control circuit 4. The closed-loop iron core 3 of the saturable reactor has at least two iron core columns having the same cross-sectional area and coils; each of the two iron core columns can form a magnetic flux closed loop which does not pass through the opposite core column.

The closed-loop iron core 3 has two iron core columns with the same cross-sectional area, one of which has a coil L1, a coil L3 and a coil L5; the other iron core has a coil L2, a coil L4 and a coil L6; the coil L1 The number of turns of the coil L2 is equal; the number of turns of the coil L3 and the coil L4 is equal; the number of turns of the coil L5 and the coil L6 is equal; the number of turns of the coil L1 and the coil L5 is not equal; and the number of turns of the coil L3 and the coil L5 is not equal. The same name end of the coil L1 and the coil L2 is connected to the terminal I1, the different end of the coil L1 is connected to the same end of the coil L4, the different end of the coil L2 is connected to the same end of the coil L3, and the different end of the coil L3 and the coil L4 is connected to the terminal II2. The same name end of the coil L5 is connected to the different name end of the coil L1, the same name end of the coil L6 is connected to the different name end of the coil L2, and the different names of the coil L5 and the coil L6 are respectively connected to the terminal II2 via the forward thyristor D1 and the reverse thyristor D2. The control terminals of the thyristor D1 and the thyristor D2 are respectively connected to the control circuit 4.

A diode D3 is also connected between the different end of the coil L1 and the different end of the coil L2.

A saturation reactor that shortens the transient response time is connected to a power system with a rated voltage of U1. When the control circuit 4 controls the thyristor D1 and the thyristor D2 to be fully turned off, the saturated reactor has a maximum reactance value Zmax.

When the control circuit 4 controls the thyristor D1 and the thyristor D2 to be fully turned on, the saturable reactor has a minimum reactance value Zmin.

The control circuit 4 continuously controls the magnitude of the rectification of the thyristor D1 and the thyristor D2, and can continuously adjust the reactance value of the saturable reactor, and the reactance value of the saturable reactor is adjusted and changed between the maximum value and the minimum value.

The experiment shows that the direct current in the coil L1 and the coil L5 of the same core column is directed downward, and the direct current in the coil L2 and the coil L6 of the same core column is upward. There is no collision in the transient response trend. The effect of shortening the transient response time in this embodiment is not as good as in the first embodiment.

Single-phase saturable reactors can be extended to three-phase saturable reactors. The promotion method is public knowledge and is no longer cumbersome.

The saturated reactor for shortening the transient response time of the invention can be designed and manufactured by using the prior art, can be completely realized, and has broad application prospects.

Claims

A saturable reactor for shortening transient response time, which is single-phase, including a closed-loop iron core of a saturated reactor, coils mounted on two iron cores of a closed-loop iron core, thyristors connected to each coil, and control Thyristor control circuit; characterized in that

There are three coils on each of the iron core columns, and the number of turns of the three coils is different, but the number of turns of the coils at the same position on the two iron core columns is the same;

The opposite end of the coil at the first position on one of the core legs is connected to the end of the same name of the coil at the second position on the other core post;

The same name end of the coil of the third position on one of the iron core columns is connected to the same end of the coil of the second position of the iron core column;

The different names of the coils at the third position on each iron core column are respectively connected with a thyristor, and the control end of the thyristor is connected with the control circuit, and the control circuit controls the magnitude of the firing angle of the thyristor to continuously adjust the magnitude of the thyristor rectification amount;

The transient response of the coil at the first position on the same core column and the coil at the third position are opposite, offsetting most of the transient response time, resulting in a shortened overall transient response time of the saturable reactor.
A saturable reactor for shortening transient response time, which is single-phase, including a closed-loop iron core of a saturated reactor, coils mounted on two iron cores of a closed-loop iron core, thyristors connected to each coil, and control Thyristor control circuit; characterized in that

There are three coils on each of the iron core columns, and the number of turns of the three coils is different, but the number of turns of the coils at the same position on the two iron core columns is the same;

The opposite end of the coil at the first position on one of the core legs is connected to the end of the same name of the coil at the second position on the other core post;

The same name end of the coil of the third position on one of the iron core columns is connected to the opposite end of the coil of the first position of the iron core column;

The different names of the coils at the third position on each iron core column are respectively connected with a thyristor, and the control end of the thyristor is connected with the control circuit, and the control circuit controls the magnitude of the firing angle of the thyristor to continuously adjust the magnitude of the thyristor rectification amount.
A saturable reactor for shortening transient response time according to claim 1 or 2, wherein a diode is connected between the opposite end of the first position coil and the end of the second position coil of the second position coil.
A saturable reactor for shortening transient response time according to claim 3, wherein the two coils and the diode at the first position on the two core legs are high when the control circuit controls the firing angle of the thyristor Subharmonic rectification path;

When the power frequency flux in the two iron core columns is unbalanced, the diode provides a half-wave rectified excitation current to balance the power frequency flux in the two iron core columns.
A saturable reactor for shortening transient response time according to claim 4, wherein said diode is connected in parallel with a resistor.
The saturation reactor for shortening the transient response time according to claim 1 or 2, wherein when the thyristor is fully turned off, the saturated reactor has a maximum reactance value, and an alternating current voltage is applied across the thyristor;

When the thyristor is fully turned on, the saturable reactor has a minimum reactance value, and the thyristor constitutes a half-wave rectifying circuit.
The saturable reactor for shortening transient response time according to claim 6, wherein when the thyristor is turned on, the two core legs generate DC magnetic fluxes having opposite directions.
The saturation reactor for shortening the transient response time according to claim 1 or 2, wherein the two core legs have the same cross-sectional area, and each of them has at least one magnetic flux closed loop that does not pass through the opposite core leg.
The saturable reactor for shortening transient response time according to claim 1 or 2, wherein the closed-loop iron core is two closed-loop iron cores having no passages with each other or an integrated closed-loop iron core having mutual passage.
A saturable reactor for shortening transient response time, characterized in that it is a three-phase shortened transient response time of a saturable reactor with a single-phase shortened transient response time according to any one of claims 1-2 Saturated reactor.