CN108683164A - Saturable reactor and its parameter tuning method, device and emulator - Google Patents

Abstract

The invention provides a saturable reactor and its parameter setting method, device and simulation equipment. A parallel branch composed of a branch resistance and a branch reactor is connected in parallel at both ends of the existing main saturable reactor to transfer The loss of the main saturated reactor reduces the loss and the temperature rise. Under the premise of not changing the core material and overall structure of the main saturable reactor and not changing the protection performance of the saturable reactor to the thyristor, the loss of the main saturable reactor is reduced, and the temperature rise characteristic is optimized.

Description

Saturated reactor and its parameter setting method, device and simulation equipment

technical field

The invention relates to the technical field of direct current transmission, in particular to a saturated reactor and its parameter setting method, device and simulation equipment.

Background technique

The saturable reactor is an important protection element in the DC transmission converter valve. Its function is to limit the rapid rise of the current when the thyristor is turned on, and to divide the voltage in the circuit when the thyristor is turned off. Judging from the operation of DC transmission projects that have been put into operation, the current saturable reactors can effectively protect the reliable opening of thyristors, but most of them have deficiencies in loss and heat dissipation. In the prior art, the saturated reactor of the converter valve adopts various methods to reduce the temperature rise. First, the winding adopts a hollow tube to pass water to dissipate heat, and a water-cooled heat sink is fixed between the iron cores. Natural cooling, this structure can effectively improve the temperature rise characteristics of the reactor, but the waterway structure is complex and the failure rate is high. 2. The saturated reactor of the converter valve adopts a shell-type overall potting structure, and the winding also adopts a hollow tube to pass water to dissipate heat, but the iron core adopts a natural cooling method, so the temperature rise of the iron core is relatively high. 3. Combining the second type of saturated reactor structure, but adding a core radiator to improve the heat dissipation conditions of the core and reduce the temperature rise, but because the core radiator is placed on the inner wall of the reactor, the air flow rate of the inner wall is low, resulting in the overall The improvement in temperature rise is very limited. 4. Use lower loss iron core to directly reduce the loss of the saturable reactor. At present, the iron core loss used in the saturable reactor is already very low. If the loss is further reduced, it will bring about problems such as increased cost and reduced saturation magnetic density.

Therefore, how to effectively reduce the core loss of the saturable reactor and improve its temperature rise characteristics has become an urgent problem to be solved.

Contents of the invention

The technical problem to be solved by the invention is to effectively reduce the core loss of the saturated reactor and improve its temperature rise characteristics.

According to the first aspect, an embodiment of the present invention provides a saturable reactor, including: a main saturable reactor; a parallel branch, including: a branch resistor and a branch reactor connected in series in sequence, connected in parallel with the main saturable reactor, using It is used to transfer the loss of the main saturated reactor.

Optionally, the branch reactor includes: a branch linear reactor, which is used to transfer the loss of the main saturated reactor to the parallel branch when the converter valve is turned on and off.

Optionally, the branch reactor includes: a branch saturable reactor, which is used to transfer the loss of the main saturated reactor to the parallel branch when the converter valve is turned off.

Optionally, the winding of the main saturated reactor is a hollow tube, and the hollow tube is a coolant channel for cooling the iron core and the winding; the parallel branch is integrally packaged and arranged on a water-cooled heat sink.

Optionally, the branch circuit resistors are arranged on both sides of the branch circuit reactor in columns, and arranged on the water-cooled heat sink.

Optionally, one side of the iron core of the branch reactor is fixed on the water-cooled heat sink through a metal clip.

Optionally, a gap with a preset width is provided at the fastening joint between the iron cores of the main saturated reactor and the branch reactor, and a gap pad corresponding to the gap width is bonded in the gap.

According to the second aspect, an embodiment of the present invention provides a parameter tuning method for a saturable reactor. The parameter tuning method is used to tune the parameters of the parallel branch of the saturable reactor. The parameter tuning method includes: according to any of the above first aspects The parameters of the main saturated reactor in the saturated reactor and the structure of the parallel branch obtain the initial parameters of the parallel branch; bring the initial parameters into the converter valve where the saturated reactor is located to calculate the saturated reactor under several operating conditions The loss; adjust the initial parameters of the parallel branch according to the loss, and obtain the tuning parameters of the parallel branch.

Optionally, bringing the initial parameters into the converter valve where the saturated reactor is located to calculate the loss of the saturated reactor under several operating conditions includes: investigating the operating performance of the saturated reactor in the converter valve; judging the operation of the converter valve Whether the performance meets the preset operating performance; when the operating performance of the converter valve meets the preset operating performance, calculate the loss of the saturated reactor under several operating conditions.

Optionally, when the operating performance of the converter valve does not reach the preset operating performance, return to the parameters of the main saturated reactor in the saturated reactor according to any one of the above-mentioned first aspects and the structure of the parallel branch to obtain the parameters of the parallel branch Steps with initial parameters.

Optionally, adjusting the initial parameters of the parallel branch according to the loss to obtain the setting parameters of the parallel branch includes: judging whether the loss exceeds the preset loss, and when the loss exceeds the preset loss, returning to the saturable reactor according to any one of the first aspect above The parameters of the main saturated reactor and the structure of the parallel branch in the step of obtaining the initial parameters of the parallel branch.

According to the third aspect, an embodiment of the present invention provides a parameter setting device for a saturable reactor. The parameter setting device is used to set the parameters of the parallel branch of the saturable reactor. On the one hand, the parameters of the main saturable reactor in any one of the saturable reactors and the structure of the parallel branch obtain the initial parameters of the parallel branch; the calculation module is used to bring the initial parameters into the converter valve where the saturable reactor is located for calculation The loss of the saturated reactor under several operating conditions; the adjustment module is used to adjust the initial parameters of the parallel branch according to the loss ratio, and obtain the setting parameters of the parallel branch.

According to a fourth aspect, an embodiment of the present invention provides a simulation device, including: a controller, including: at least one processor; and a memory connected to at least one processor in communication; wherein, the memory stores information that can be executed by a processor. instructions, the instructions are executed by at least one processor, so that at least one processor executes the parameter tuning method for a saturable reactor according to any one of the first aspect above.

In the saturable reactor and its parameter setting method, device and simulation equipment provided by the embodiment of the present invention, a parallel branch transfer including branch resistors and branch reactors connected in series is connected in parallel at both ends of the existing main saturable reactor. The loss of the main saturated reactor is reduced, the loss is reduced, and the temperature rise is reduced. Under the premise of not changing the core material and overall structure of the main saturable reactor and not changing the protection performance of the thyristor by the saturable reactor, the loss of the main saturable reactor is reduced and the temperature rise characteristic is optimized.

Description of drawings

FIG. 1 shows a schematic diagram of a modular structure of a saturable reactor according to an embodiment of the present invention;

Fig. 2 shows a schematic flow chart of a parameter tuning method for a saturable reactor according to an embodiment of the present invention;

Fig. 3 shows the schematic circuit diagram of the saturable reactor of the embodiment of the present invention;

FIG. 4 shows a schematic circuit diagram of another saturable reactor according to an embodiment of the present invention;

Fig. 5 shows the schematic diagram of the saturable reactor parameter setting device of the embodiment of the present invention;

Fig. 6 shows a schematic diagram of a simulation device according to an embodiment of the present invention.

Detailed ways

The technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Apparently, the described embodiments are some of the embodiments of the present invention, but not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

An embodiment of the present invention provides a saturable reactor. As shown in FIG. 1, the saturable reactor may include:

The main saturated reactor 10; the parallel branch 20, including: a branch resistance 21 and a branch reactor 22 connected in series in sequence, connected in parallel with the main saturated reactor, and used to transfer the loss of the main saturated reactor. In this embodiment, the main saturated reactor adopts the existing saturated reactor, and a parallel branch is incorporated at both ends of the main saturated reactor, and the branch can be composed of a branch resistor 21 and a branch reactor 22 In this embodiment, since the loss of the saturable reactor is mainly caused by the voltage jump of the converter valve where the saturable reactor is located and other converter valves when they are turned on or off, the parallel branch, When the voltage jumps when the converter valve is turned on or off, the main saturated reactor can be shunted, so as to transfer the loss of the main saturated reactor. In this embodiment, the branch resistance can be a constant resistance. The smaller the value of the branch resistance, the smaller the branch impedance, the more obvious the shunt effect on the main reactor, and the more the transfer ratio of the loss of the main saturated reactor , in this embodiment, the branch resistance can take a smaller value.

A parallel branch composed of a branch resistor and a branch reactor is connected in parallel at both ends of the existing main saturated reactor to transfer the loss of the main saturated reactor to reduce the loss and temperature rise. Under the premise of not changing the core material and overall structure of the main saturable reactor and not changing the protection performance of the saturable reactor to the thyristor, the loss of the main saturable reactor is reduced and the temperature rise characteristic is optimized.

In an optional embodiment, as shown in FIG. 3 , the branch reactor 22 includes: a branch linear reactor 221, which is used to transfer the loss of the main saturated reactor to the parallel branch when the converter valve is turned on and off. on the way. In this embodiment, the branch linear reactor 221 can be an inductance with constant inductance, a cored inductor, or a coreless inductor. In order to reduce the volume of the branch reactor, in this embodiment, a Core inductor. When the branch reactor is the branch linear reactor 221, the selection of the branch reactance value will affect the protection characteristics of the saturable reactor to the thyristor. Usually, the inductance value of the linear reactor is small, in order to reduce the reactor’s protection to the thyristor. The influence of protection characteristics, in this embodiment, the inductance value is the same order of magnitude as the unsaturated inductance of the main reactor, but should be smaller than the unsaturated inductance value of the main reactor. Since the inductance value of the branch linear reactor 221 is constant, the branch reactor plays the role of transferring the loss of the main reactor at the moment of turning on and turning off.

In order to reduce the influence of the saturable reactor on the protection characteristics of the thyristor, in an optional embodiment, as shown in Figure 4, the branch reactor can also be a branch saturable reactor 222, which is used to When , the loss of the main saturated reactor is transferred to the parallel branch. In this embodiment, in order not to increase the volume of the saturable reactor, the branch saturable reactor 222 should adopt a structure of small iron core and multiple windings; When using the link-current curve, the saturation flux linkage of the branch cannot be selected too small, and should be equal to or slightly lower than the saturation flux linkage of the main saturated reactor. In this embodiment, at the initial moment when the converter valve is turned on, the branch saturated reactor 222 is not saturated, the inductance value is relatively large, and the parallel branch is approximately open. It will make the parallel saturated reactor re-enter the saturated state from the unsaturated state, and play the role of shunt and transfer loss.

In an optional embodiment, the main saturated reactor is a shell-type reactor structure; the branch reactor is a core-type reactor structure; the main saturated reactor and the branch reactor are arranged separately. In this embodiment, the main saturated reactor and the parallel branch can be placed integrally or separately. In order to avoid excessive concentration of weight, facilitate inspection and maintenance, and help realize industrial production, in this embodiment, the main saturated reactor The reactor and the branch reactor are set separately. In this embodiment, the main saturated reactor adopts a shell-type saturated reactor structure, and a hollow tube is used as the reactor winding. The material of the hollow tube can be aluminum or copper, and other hollow tubes that can be used as windings can be used as this embodiment. The winding of the reactor in the reactor, the hollow tube is the coolant channel, used to cool the iron core and the winding, the tube is cast in epoxy resin as a whole, which not only ensures the insulation between the turns of the tube and the external insulation, but also enhances the mechanical properties of the saturated reactor. strength. The iron core is fixed on the winding after pouring, and then the whole is encapsulated in the shell with an elastic body. The design of the main saturable reactor adopts the following optimization process: the core with low loss and low magnetostriction rate not only reduces the calorific value of the core, but also the magnetostriction rate of the core material is much smaller than that of the current saturable reactor core material, Therefore, the vibration characteristics of the saturable reactor can be significantly improved. High thermal conductivity epoxy resin cast tube. The core heat of shell-type reactor can be dissipated to the outside of the reactor through the elastomer and the shell, and can also be dissipated to the internal cooling water through the epoxy resin reaching tube. Since the thermal conductivity of the epoxy resin is very low, the heat transferred from the iron core to the tube is very small. The embodiment of the present invention adopts an optimized formula of high thermal conductivity epoxy resin to accelerate the release of heat from the iron core. Bond the core air gap with adhesive. The electromagnetic attraction force caused by magnetic flux leakage between the air gap of the silicon steel sheet and the laminations is one of the main factors causing the vibration of the iron core. Bonding the air gap of the iron core with adhesive can reduce the collision between the contact surfaces. Tests show that under the same excitation, the vibration and noise of the bonded iron core are significantly reduced.

In an optional embodiment, the branch saturated reactor 222 has a multi-winding structure. In this embodiment, only a pair of iron cores are used, and the winding is designed to be multi-turn, so that the volt-seconds of the shunt reactor and the main saturated reactor are similar. The shunt resistors are placed around the shunt reactors and are integrally packaged in the housing with elastomers. The elastomer has a large internal loss factor, which can increase the overall damping characteristics of the saturable reactor, thereby reducing vibration. The following optimization process is adopted in the design of the parallel branch circuit: the same as the main saturated reactor, the branch circuit saturated reactor 222 adopts an iron core with low loss and low magnetostriction rate; the branch circuit saturated reactor 222 and the branch circuit resistance adopt integral casting Packaged structure.

The branch resistance will also generate a large amount of heat during the operation of the reactor. In order to increase the heat dissipation of the branch resistance, in an optional embodiment, the branch resistance is arranged on both sides of the branch reactor. Water-cooled radiator plate. The branch circuit resistors are arranged separately on both sides of the branch circuit reactor, and can be fixed on the water-cooled heat dissipation plate through metal clips to dissipate heat by means of the water-cooled heat dissipation plate. The shunt reactor and the shunt resistor are packaged together in the same shell with an elastomer. The elastomer has a large internal loss factor, which can increase the overall damping characteristics of the saturable reactor, thereby reducing vibration.

In order to further reduce vibration noise, in an optional embodiment, a gap with a preset width is provided at the fastening joint between the iron cores of the main saturated reactor and the branch reactor, and a gap corresponding to the gap width is bonded in the gap. gap pad. In a specific embodiment, the iron core is a C-shaped or U-shaped structure, which is buckled in pairs on the straight section of the winding and fixed by a metal clip. There is an air gap between each pair of iron cores, and the width of the air gap is determined by the standard The thickness of the air gap pad is controlled, and the air gap can be adjusted according to the electrical performance design of the saturated reactor. By bonding the air gap surface of the iron core, the propagation of vibration can be damped, thereby achieving the effect of reducing noise.

The embodiment of the present invention also provides a parameter tuning method of a saturable reactor, the parameter tuning method is used to tune the parameters of the parallel branch of the saturable reactor, as shown in Figure 2, the parameter tuning method includes:

S10. Determine the initial parameters of the parallel branch according to the parameters of the main saturated reactor in the saturated reactor and the structure of the parallel branch. In a specific embodiment, since the main saturable reactor adopts a conventional saturable reactor, the parameters of the main reactor are mainly determined by the joint design of the parameters of other components of the converter valve. The parameters of the main saturable reactor include: main reactor hollow Inductance L _a , main reactor winding resistance R _cu , main reactor excitation inductance L _m (which can be expressed by the flux linkage-current curve of the iron core) and resistance R _m representing the eddy current loss of the iron core. Therefore, the parameters of the saturable reactor are mainly the parameters of the parallel branch. In this embodiment, the parameters required for different structures of the parallel branch are different. As shown in FIG. 3, when the branch reactor is a linear inductance, The main parameters are branch inductance value L _z and branch resistance value R _z . Specifically, the branch inductance L _z is of the same order of magnitude as the inductance of the main saturated reactor when it is not saturated, but it should be smaller than the unsaturated inductance of the main saturated reactor.

As shown in Figure 4, when the branch reactor is a branch saturated reactor 222, there are branch resistance R _z , the air-core inductance L _za of the branch saturated reactor 222, the winding resistance R _zcu , and the excitation of the main reactor The inductance L _zm (flux linkage-current curve of the iron core) and the resistance R _zm representing the eddy current loss of the iron core. Specifically, in order to ensure the overall suppression of the current rise rate by the saturable reactor, when selecting the core flux linkage-current curve, the saturation flux linkage cannot be selected too small, and should be equal to or slightly lower than the saturation flux linkage of the main reactor; the reactor The air-core inductance L _za and the winding resistance R _zcu are smaller and can be ignored for the time being. The smaller the value R _z of the branch resistance is, the smaller the branch impedance is, and the shunting effect on the main reactor is more obvious, so the branch resistance can take a smaller value. The initial parameters are selected according to the above-mentioned parallel branch structure and selection rules. In this embodiment, multiple sets of initial parameters can be selected for backup.

S20. Bring the initial parameters into the converter valve where the saturable reactor is located to control the operation of the converter valve. After the initial parameters are selected, the operation of the converter valve where the saturable reactor is located can be simulated according to the selected initial parameters.

S30. Judging whether the operating performance of the converter valve meets the preset operating performance. When the operating performance of the converter valve meets the preset operating performance, go to step S40. When the operating performance of the converter valve does not reach the preset operating performance, return to step S10 and reselect the initial parameters.

S40. Calculate the loss of the saturable reactor under several operating conditions. In this embodiment, when the converter valve is running, the loss of the main saturated reactor, the loss of the branch reactor and the branch resistance are collected. Moreover, it is possible to simulate the loss of the main saturable reactor when the saturable reactor is running under different working conditions, as well as the loss of the branch reactor and the branch resistance. In this embodiment, it is also possible to The loss of the branch reactor and the loss of the branch circuit are calculated to calculate the loss ratio of the parallel branch, and the effect of the parallel branch on reducing the loss of the main saturated reactor can be clearly obtained.

S50. Determine whether the loss exceeds a preset loss. In this embodiment, the preset loss can be set for the loss of the main saturated reactor, and it can be judged whether the loss of the main saturated reactor exceeds the preset loss. When the loss exceeds the preset loss, return to step S10 and reselect Initial parameters, when the loss does not exceed the preset loss, go to step S60.

S60. Determine that the selected parameter is a setting parameter of the parallel branch.

In this embodiment, by simulating the operation of the saturated reactor and setting the parallel branch, the loss of the main saturated reactor can be reduced by 20% to 40%, while the overall performance of the Flow valve operation requirements.

Determine the initial parameters of the parallel branch according to the parameters of the main saturable reactor and the structure of the parallel branch, and bring the initial parameters into the converter valve where the saturable reactor is located to calculate the loss of the saturable reactor under several operating conditions; adjust according to the loss The initial parameters of the parallel branch are obtained to obtain the setting parameters of the parallel branch. The parameters of the parallel branch can be accurately matched with the parameters of the main reactor, which not only ensures that the basic electrical performance of the main saturated reactor is not affected, but also reduces the loss of the main saturated reactor and optimizes the temperature rise characteristics.

The embodiment of the present invention also provides a parameter setting device for a saturable reactor, as shown in FIG. 5 , the device includes: an acquisition module 100, which is used to Determine the initial parameters of the parallel branch; the calculation module 200 is used to bring the initial parameters into the converter valve where the saturated reactor is located to calculate the loss of the saturated reactor under several operating conditions; the adjustment module 300 is used to calculate the loss according to the loss ratio Adjust the initial parameters of the parallel branch to obtain the tuning parameters of the parallel branch.

An embodiment of the present invention provides a simulation device, as shown in Figure 6, the simulation device is used to simulate the operation of the reactor to adjust the parameters of the reactor, the simulation device includes one or more processors 61 and The memory 62, a processor 63 is taken as an example in FIG. 6 .

The simulation device may further include: an input device 63 and an output device 64 . The input device 63 in the simulation device can receive the parameter information of the input reactor, for example, select a group of parallel branch parameters to input to the simulation device, and simulate the complete saturable reactor topology; the output device 64 displays the simulation result, for example, can It shows the operating performance of the saturable reactor in the converter valve, including but not limited to the following main characteristics: the suppression of the saturable reactor on the rate of rise of the opening current; the oscillation characteristics of the opening current under transient conditions, whether the current valley value Zero crossing point; change of main reactor voltage stress after adding parallel branch; output device 64 can also display loss information including main reactor loss, branch resistance loss, branch reactor loss, and loss analysis results. The memory 62 can store a simulation program and simulation parameters, and the processor 61 can call the simulation program stored in the memory 62 to execute the method for parameter setting of the saturable reactor in the above embodiment.

Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention. Such modifications and variations all fall into the scope of the appended claims. within the limited range.

Claims (13)

1. A saturable reactor, characterized in that, comprising: main saturable reactor; The parallel branch includes: a branch resistance and a branch reactor connected in series in sequence, connected in parallel with the main saturable reactor, and used to transfer the loss of the main saturable reactor. 2. The saturable reactor according to claim 1, wherein the branch reactor comprises: The branch linear reactor is used to transfer the loss of the main saturated reactor to the parallel branch when the converter valve is turned on and off. 3. The saturable reactor according to claim 1, wherein the branch reactor comprises: The branch saturable reactor is used to transfer the loss of the main saturated reactor to the parallel branch when the converter valve is turned off. 4. The saturable reactor according to claim 1, characterized in that, The winding of the main saturated reactor is a hollow tube, and the hollow tube is a cooling liquid channel for cooling the iron core and the winding; The parallel branch is integrally packaged and arranged on the water-cooled heat dissipation plate. 5. The saturable reactor according to claim 4, characterized in that, The branch circuit resistors are arranged on both sides of the branch circuit reactor and arranged on the water-cooled heat dissipation plate. 6. The saturable reactor according to claim 5, characterized in that, One side of the iron core of the branch reactor is fixed on the water-cooled heat dissipation plate through a metal clip. 7. The saturable reactor according to claim 5 or 6, characterized in that, A gap with a preset width is provided at the fastening joint between the iron cores of the main saturated reactor and the branch reactor, and a gap pad corresponding to the width of the gap is bonded in the gap. 8. A parameter tuning method for a saturable reactor, characterized in that the parameter tuning method is used for tuning the parameters of the parallel branch of the saturable reactor, including: Acquire the initial parameters of the parallel branch according to the parameters of the main saturated reactor in the saturated reactor according to any one of claims 1-7 and the structure of the parallel branch; Bring the initial parameters into the converter valve where the saturable reactor is located to calculate the loss of the saturable reactor under several operating conditions; Adjusting the initial parameter of the parallel branch according to the loss to obtain the setting parameter of the parallel branch. 9. The parameter setting method according to claim 8, wherein said bringing said initial parameters into the converter valve where the saturable reactor is located to calculate the loss of said saturable reactor under several operating conditions comprises: Investigate the operational performance of the saturable reactor in the converter valve; judging whether the operating performance of the converter valve meets the preset operating performance; When the operating performance of the converter valve satisfies the preset operating performance, the loss of the saturable reactor under several operating conditions is calculated. 10. The parameter setting method according to claim 9, characterized in that, when the operating performance of the diverter valve does not reach the preset operating performance, return to the method according to any one of claims 1-7. The parameters of the main saturable reactor in the saturated reactor and the structure of the parallel branch are the steps of obtaining the initial parameters of the parallel branch. 11. The parameter setting method according to claim 8, wherein said adjusting the initial parameter of said parallel branch according to said loss, and obtaining the setting parameter of parallel branch include: judging whether the loss exceeds a preset loss, When the loss exceeds the preset loss, return to the parameters of the main saturated reactor in the saturated reactor according to any one of claims 1-7 and the structure of the parallel branch to obtain the initial parameters of the parallel branch step. 12. A parameter setting device for a saturable reactor, characterized in that the parameter setting device is used to set the parameters of the parallel branch of the saturable reactor, and the device includes: An acquisition module, configured to acquire the initial parameters of the parallel branch according to the parameters of the main saturated reactor in the saturable reactor according to any one of claims 1-7 and the structure of the parallel branch; A calculation module, configured to bring the initial parameters into the converter valve where the saturable reactor is located to calculate the loss of the saturable reactor under several operating conditions; An adjustment module, configured to adjust the initial parameters of the parallel branch according to the loss proportion to obtain the setting parameters of the parallel branch. 13. A simulation device, characterized in that it comprises: a controller, including: at least one processor; and a memory connected in communication with at least one processor; wherein, the memory stores instructions that can be executed by a processor, and the instructions are Execution by at least one processor, so that at least one processor executes the parameter tuning method for a saturated reactor according to any one of claims 8-11.