WO2014140385A1

WO2014140385A1 - Device for generating disturbances in an electrical grid

Info

Publication number: WO2014140385A1
Application number: PCT/ES2013/000068
Authority: WO
Inventors: Ugena González David; Manuel Tena Cerezo José; Daniel Castagnola Nestor; Logrosán Diaz Higinio; Hermoso Garcia César
Original assignee: Wynnertech (Beijing) Co., Ltd.
Priority date: 2013-03-13
Filing date: 2013-03-13
Publication date: 2014-09-18
Also published as: CN104520725A

Abstract

The invention relates to a device for generating network disturbances at a generator, comprising an inductive voltage divider (34) including a control unit (2), a bench of 6 inductors (28 to 33) connected to one another via a matrix of 18 isolators (5 to 22) and 5 coupled switches (23 to 27). The following can be coupled to the divider (34): a set of transformers (40, 43); a bank of capacitors and resistors (75); and an overvoltage module (OVRT, 79). The device can be used to perform tests for generator (3) power values of between 0 kW and 8.00 kW. The overvoltage test is performed by passing short-circuit current through coils (77) coupled to coils (78), generating 403 different configurations and producing 2,821 different overvoltages using combinations of the inductors (28 to 33), isolators (5 to 16) and (17 to 22) and switches (24 to 27).

Description

Device to generate disturbances in an electrical network. Sector of the technique.

The present invention relates to a device for generating disturbances in an electrical network based on a configurable inductive matrix voltage divider. This invention falls within the field of the technique of measurements of electrical and magnetic variables.

State of the Technique

Voltage gaps are sudden drops in voltage caused mainly by faults in the network and are random in nature. The holes are characterized by the magnitude of tension and duration. It can also cause jumps in phases of the voltage wave.

At present, it is known in the state of the art the Spanish patent 2,264,882 relating to a device generating voltage gaps in low voltage. The proposed solution is based on using a transformer at the output of the network and the series arrangement of impedances. With this device it is possible to analyze 8 different types of "LVRT of the English" Low voltage ride through ", that is, with a falling edge and another rising edge for the three phase, two phase and single phase openings, such as shown in figure 7.

It is also known Spanish patent 2,263,375 relating to a device generating voltage gaps. As in the previous case, this invention aims to generate simple three-phase, two-phase and single-phase voltage gaps with or without earth producing 3 variations of gaps with the help of transformers. This document focuses on low and medium voltage although it does not define them, so it is not possible to know the operating ranges.

These two priorities are limited to perform a limited number of disturbances, centered on simple voltage gaps, does not cover other disturbances in the network as double hollow, step gap, overvoltages and does not address the need associated with the transport of these devices.

The Chinese patent CN 102129036 improves the previous technical solutions and exposes a transportable device in a standard container 40 feet long (12,192 m) for transport of goods. This device is connected in series between the wind turbine of the generator and the electrical network and uses a bank of inductances with intermediate sockets in series, a bank of inductances with intermediate sockets in parallel and switches static, like thyristors. Combining the impedances of the benches, this invention allows simple holes to be made, as well as generating voltage gaps with stepped recovery. The adjustment of the different elements of this device is based on the use of power electronics devices such as thyristors and coils with intermediate plugs, which can produce robustness problems and magnetic saturation effects. However, this invention does not allow tests of the behavior of a generator to other dysfunctions, disturbances, of the electrical network and the device presents difficulties in its transport due to its large volume.

Finally, the operating ranges of the foregoing exposures are not known exactly because they do not define the ranges of high, low and medium voltage in which they work.

The nomenclature used in this document, accepted in the literature of electrical engineering, identifies the three phases and the neutral of the electric current with the letters A, B, C and N for the first, second, third and neutral phases.

On the other hand the type of voids used in the article is used ("Different methods for classification of three-phase unbalanced voltage dips due to faults", article published by Electric Power Systems Research in 2003 editorial IEEE author MHJ Bollen and LD Zhang, table 1) which are summarized in 7 different hole types Type A, Type B, Type C, Type D, Type E, Type F and Type G, of which the presented invention is capable of reproducing 5 of them, Type A, Type B, Type C, Type D and Type E.

Explanation of the invention.

The object of the present invention consists of a transportable device for generating disturbances in an electrical network both in low and medium voltage, to know the reaction and behavior of an electrical equipment either generating or consuming electrical energy in the face of these disturbances. These electrical equipment can be wind turbines, photovoltaic inverters as well as other electric power generators or motors or passive loads that require the necessary accreditations to be able to connect to the public power network according to the regulations of each country. In this way, the network requirements imposed on the electricity generating equipment, especially those of renewable origin, by official bodies are met. For this, the present invention generates in a controlled manner the different disturbances of network to which the electric generators have to face and that the official organisms of each country have determined as valid proof to determine their suitability, and thus allow the connection to the network guaranteeing the supply of energy with quality and under common criteria to all the components of the electric generation set. With this invention, the following problems are answered:

• Versatility in operation. This equipment is capable of adapting to different legislations, networks, generators and loads without having to use additional elements. That is, it can operate in a wide range of voltages and generate a large number of disturbances without the need to add additional elements for its operation, as will be explained later.

• All the equipment, especially the voltage divider, is mounted in a standard container, which is coupled with an autonomous lifting system which facilitates its transport as well as its easy placement in the vicinity of the electric generator, without the need for cranes auxiliaries

• Inside the container all the necessary elements that make up the control equipment are included, including probes, making this equipment compact. These elements of the control team are specific for obtaining, storing and monitoring the variables of measures to be carried out. All the operation of the device is managed from the control equipment through mechanical switches without power electronics, compared to the previous solutions.

• Through the control equipment, the supervision and configuration of the equipment is carried out by the operator in an easy and intuitive way, not requiring the specialization of the worker for its management.

The device for generating disturbances comprises a configuous matrix inductive voltage divider, hereinafter a divider, which can optionally be coupled to a set of transformers, a bank of additional coupled coils, and a bank of capacitors and resistors individually or jointly, in such a way that the coupling can be:

• The divider is located behind the generator as well as the electrical network. • After the generator as well as the electrical network, the set of transformers is located and then the divider.

• After the generator as well as the electrical network, the bank of capacitors and resistors is located and then the divider.

• The set of additional coils coupled with the divider is located behind the generator as well as the electrical network.

• After the generator as well as the electrical network, the set of transformers is located and then the capacitor bank that connects with the divider.

• After the generator as well as the electrical network, the set of transformers is located and then the set of coils coupled together with the divider.

• After the generator as well as the electrical network, the set of transformers is located and later the bank of capacitors and resistors and the set of coils coupled together with the divider are located. ivisor is located between the electric generator and the network and comprises:

• A cabinet that includes the control and monitoring equipment of the divider and, where appropriate, the transformers, capacitor bank, resistor bank and coupled coils. This team includes the following elements:

o Input and output voltage and current measurement systems. In this case, the probes are composed of voltage probes based on voltage-to-voltage Hall effect transducers that measure the voltage instantaneously with a sample rate of at least 100,000 samples / second and 16 bits of resolution and based current probes in Rogowski type current-to-voltage transducers that measure the alternating current instantaneously with a sampling frequency of at least 100,000 samples / second and 16 bits of resolution. All probes are monitored by the divider control equipment.

o Control system by means of a programmable logic controller (PLC) and a man-machine interface (HMI) from where the operator can enter the configuration parameters of the equipment, the type of gap, length of the gap, depth of the gap, short-circuit current of the hole, etc. o Data acquisition system, from which all the measured variables can be visualized and additional mathematical operations can be performed to calculate parameters such as power, power factor, harmonics, direct sequence, inverse and homopolar.

o Storage system of at least 1 TB where all the records of the variables measured and calculated for subsequent queries can be saved.

In case of working in low voltage, the equipment is coupled directly to the generator. This equipment includes a probe per phase to measure the input voltage and voltage at low voltage at the generator input as well as three other current and voltage measurement probes at high voltage at the network output. In the case that the network is of medium or high voltage, each probe of the control equipment is coupled with the input of the electric generator as it is exposed in the first variant to this embodiment.

• One bank per phase of 6 inductances represented as XI to X6. The bench is formed by a group by phase, in total 3 groups of 6 coils. These coils that make up the inductances are air core to avoid saturation and loss of physical magnitudes due to current. These 18 coils are intended to act as impedances and, with the help of switches, obtain a specific short-circuit current. The relationship that exists between the inductances and their placement is X1 = X6, 4X1 = X2 = X5, 8X1 = X3 = X4. That is, following the order of placement the first (XI) and last (X6) inductance have the same value; the value of the second (X2) and fifth (X5) inductance is the same and corresponds to 4 times the impedance of the first (XI) and last inductance (X6); the third (X3) and fourth (X4) inductance has a value of 8 times the value of XI and X6.

• 12 disconnectors of the value of the nominal current of the equipment that act as disconnectors of configuration of impedances that connect to each other to the 6 inductances and other 6 disconnectors of the value of the nominal current of the equipment that act as disconnectors of voltage configuration.

• 5 coupled switches. 4 of these switches are different from the disconnectors because they are 1/3 rated current of the equipment that the rest of the disconnectors, since the three poles are used for the same phase. In addition, the use of switches allows to have associated an opening capacity before high short-circuit current, that is to say it has cutting power, in front of the disconnector that lacks this opening capacity. The first circuit breaker is of short circuit, being this the value of the nominal current of the equipment and using each pole for each phase, it connects to two disconnectors of the last inductor of the inductor bank with three other switches in parallel connecting each one with only one phase. A last switch connects the three switches in parallel with the neutral of the electrical network.

With the help of the control equipment, all configurations and functionalities are made by mechanical switches without power electronics, making the device more robust. The operator only enters the configuration parameters from the HMI and the configurations are made by a PLC. All switches are motorized increasing the speed of configuration and manageability. The system of monitoring and storage of data is included within the equipment.

The 12 impedance configuration switches connect the 6 inductances together. These disconnectors allow to connect the different impedances in parallel or in series between them and achieve a certain short circuit current. In this way, 81 different short-circuit currents are achieved. On the other hand, the other 6 voltage configuration switches are located at the generator input and before the control equipment and allow selecting the impedance point where the test voltage is to be obtained, that is, dividing the total impedance ( Xtotal) of short circuit in two impedances: series impedance and parallel impedance.

By means of the four switches coupled to each phase and to the neutral, the type of hole to be made is selected in such a way that the following configurations can be obtained:

• Closing the 3 phase switches, a balanced three-phase gap is obtained.

• Closing the phase switches from 2 to 2 achieves an isolated two-phase gap.

• Closing one of the phase switches with the neutral switch connected to the network produces a single-phase, closed earth hole.

• Closing the 2-in-2 phase switches with the neutral switch connected to the network provides a two-phase grounded hole. The possible combinations of the inductances (XI to X6) with the help of the disconnectors and switches allow obtaining 403 different configurations, producing 4,030 different voltage gaps. These 4,030 voltage gaps differ in the type of gap and the depth. These combinations allow testing in generators or photovoltaic inverters from 0 kilowatts (kW) to 8000kW without the need to change any component in its standard version as well as with a wide range of connection voltage without the need to change components.

The duration of each of the 4,030 configurations is also configurable and is done by controlling the time between the opening and opening state, through the closing of the short circuit breaker. In this way, time is an independent variable, the amplitude of the voltage can be configured with an accuracy of 0.5%, the duration of the gap and short-circuit current to generate:

• simple voltage gaps configuring a minimum duration of 50 milliseconds (ms) and a maximum of 10 seconds (s) compared to previous patents that reach 500ms.

• multiple holes, such as double or step gaps, configuring a duration between gaps, minimum of 50 ms and maximum of 10 s compared to the previous patents which could not be performed as well as for the steps for the step gable.

• multiple holes of the same voltage level with an interval of +/- 10ms.

• holes with different voltage levels and configure the time of each section with an error of +/- 10ms.

• Gaps of 0% of the nominal voltage value for all types of gaps. With all these elements, the divisor can create the following disturbances:

• Tension gaps of five types:

o Three-phase balanced insulated holes type A. They are voltage gaps where the three phases have the same amplitude value and the phase angle does not change. o Single phase voltage gaps to ground type B. These are voltage gaps where one of the phase voltages undergoes changes in their amplitude but not in their phase angle, being able to choose between the combination of phases AN, BN or CN. o Two-phase insulated voltage gaps type C. They are voltage gaps where two of the phase voltages undergo changes in their amplitude and phase angle, being able to choose between the combination of phases AB, AC, BC.

o D-shaped insulated two-phase voltage gaps. These are voltage gaps where two of the phase voltages undergo changes in their amplitude and phase angle, being able to choose between the combination of phases AB, AC, BC with the help of the transformer module.

o Biphasic voltage gaps to ground type E. These are voltage gaps where two of the phase voltages undergo changes in their amplitude but not in their phase angle, being able to choose between the combination of phases AB, AC or BC.

• Anti-island phenomena (Anti-islanding) for testing the protections of electric generators with the help of an anti-island module. This anti island module is formed by the module composed of resistor banks and capacitors with the help of the voltage divider coils.

• Phenomena of overvoltage through the use of an overvoltage module (OVRT of the English "Over voltage ride through") giving rise to four types of surges: o Isolated three phase balanced surges. They are overvoltages where the three phases have the same value in amplitude and the phase angle does not change, or single-phase overvoltages to ground. They are overvoltages in which one of the phase voltages suffer changes in its amplitude but not in its phase angle, being able to choose between the combination of phases AN, BN or CN.

o Isolated biphasic surges. They are overvoltages in which two of the phase voltages undergo changes in their amplitude and phase angle, being able to choose between the combination of phases AB, AC, BC.

o Biphasic ground overvoltages. They are overvoltages in which two of the phase voltages undergo changes in their amplitude but not in their phase angle, being able to choose between the combination of phases AB, AC or BC.

The first variant of this invention consists in installing between the splitter and the electrical network and the generator a set of two transformers that allow adapting the input voltage levels. This transformer module adapts and connects the splitter to a network with voltage levels higher than 690 volts (V) and lower than 35,000 V. This is useful for wind turbines that generally have the output transformer located in the upper part of the tower with a lower work voltage at 35,000 V and it is necessary to lower the voltage to the operating voltage of the generator which is 690 V. It can also be applicable in solar farms or photovoltaic inverters where the variety of voltages is very diverse and the transformer module allows to connect the device at any voltage up to 690 V without the need for any voltage adaptation. The input transformer is a 690V three-phase high or medium voltage transformer with 8000 kW star-to-star connection and its associated protection switch. On the other hand, the output transformer is a transformer to raise the voltage of 690V to a medium or high voltage with a reliable connection on the low voltage side and a star connection on the high voltage side. The configuous connection allows to connect the windings of the transformer in star or triangle, automatically and motorized through the associated disconnecting switches. This connection possibility allows you to perform the following types of gaps.

• Two-phase gaps type C when the connection is star.

· Two-phase holes type D when the connection is in a triangle.

In this case, the probes of the control equipment bypass the transformer module and are directly coupled to the input and output of the electrical generator and network.

The second variant consists in coupling an anti island module composed of three banks of three-phase capacitors and 8 banks of three-phase resistors connected in parallel with the inductances of the divider. The capacitor banks (Cl to C3) can be connected in star or triangle through their associated disconnectors being the ratio in the impedance that exists between the capacitor bank connected in triangle and star of 3. Each capacitor that forms the bank of capacitors have a value such that connected in parallel with an impedance of equal value to XI resonate with it at the frequency of 50 or 60 Hz, the reactive power consumption being 0. In this way the capacitor bank (Cl to C3) will have the value Cl = C2 = C3 = l / V (f ^A 2 * Xl), where f is the network frequency in radians / second, when the connection is in star and 3Cl, 3C2 and 3C3 when the connection is in a triangle. Each of the 8 resistance banks is composed of a resistance per phase that is coupled in star to each of the phases of the network that connects the splitter with the generator through a disconnector in such a way that the relationship that exists between the resistors are: R1 = R2, 2R1 = R3 = R4, 4R1 = R5 = R6, 8R1 = R7 = R8, where R8 is capable of consuming 1/30 of the nominal power of the equipment. These 8 resistor banks they aim to consume the active power generated by the electric power generating equipment, making the energy injected into the network null. In this case, the voltage measurement probes and the low voltage output current of the control equipment are coupled to the generator input.

With the help of this anti-island module, the island effect can be simulated by means of the capacitor banks and resistors to perform the anti island tests required by the different network regulations in force in each country. The third variant consists of coupling to the inductive divider an OVRT module consisting of a three-phase bank of two coils coupled in air together with the associated disconnectors, the coupling value being M = 8X1. The possible combinations of the inductances (XI to X6) with the help of the disconnectors and switches allow obtaining 403 different configurations, producing 2,821 different surges. These 2,821 overvoltages differ in the type of overvoltage and amplitude. These combinations allow to carry out tests on the generators with a wide range of power and voltage connection without the need to change components. That is, you can test equipment from OkW up to 8,000kW without the need to change any component in its standard version. With the help of the OVRT module, you can:

• Configure short-term overvoltages up to 140% of the nominal voltage configurable in voltage and duration level.

• Set the amplitude with an accuracy of 0.5%, duration and short-circuit current of the overvoltage.

· Make gaps with surges at the entrance or exit of the disturbance.

• Perform simple surges configuring a minimum duration of 50 ms and maximum of 10 seconds compared to previous patents.

The fourth variant of this invention consists of locating behind the transformer module, the module of three banks of capacitors and eight banks of resistors which is coupled in parallel to the inductances of the divider to the network and to the generator. This variant allows to carry out the own tests of the divisor plus those of the second and third variant. The fifth variant of this invention consists in locating, after the transformer module, the OVRT module which is coupled to the divider. This variant allows to carry out the own trials of the divisor plus those of the first and third variant.

A sixth variant based on the second variant and consists of coupling a module composed of three banks of three-phase capacitors and 8 banks of three-phase resistors connected in parallel with the inductances of the divider, the network and the load which in turn has the module attached OVRT discussed above. This variant allows to carry out the own tests of the divisor with the OVRT plus those proper to the second variant.

Finally, a seventh variant consists of locating behind the transformer module the module of three banks of three-phase capacitors and eight banks of three-phase resistors which is coupled in parallel to the inductances of the divider which in turn includes the OVRT module. This option allows all the variables and perturbations in the generator that allow the combination of the modules to be carried out.

The dividing device is mounted in a container 20 feet long (6.096 m) standard which entails an improvement as will be explained in the detailed description. In this regard, the other operating characteristics of the present invention are set forth in the detailed description with the help of the figures.

Brief explanation of the drawings.

For a better understanding of the invention, the following figures are presented:

Figure 1 shows the general scheme of the inductive divider.

Figure 2 shows a variable consisting of the inductive divider coupled to a set of transformers.

Figure 3 shows a device variable consisting of the inductive divider coupled with a bank of capacitors and another bank of resistors.

Figure 4 shows a device variable consisting of the inductive divider coupled to a bank of coupled coils. Figure 5 shows a device variable consisting of the inductive divider coupled to a set of transformers together with a bank of capacitors and another bank of resistors.

Figure 6 shows a variable of the device consisting of the inductive divider coupled to a set of transformers next to a bank of coupled coils. Figure 7 shows the variable consisting of the inductive divider coupled to a set of transformers next to a bank of coupled coils and a bank of capacitors and another bank of resistors.

Figures 8, 9 and 10 show the phase diagram of an insulated isolated three-phase hollow type A, a two-phase insulated voltage gap type C and an isolated biphase voltage gap type D, using the transformer module.

Figure 11 shows an example of a single-step gap, as is done with known devices.

Figures 12 and 13 show an example of double hollow and an example of overvoltage, both originated with the device of the present invention.

Figures 14 and 15 show two perspectives of the container that houses the divider.

Detailed description of an embodiment of the invention.

As shown in Figure 1, the object of this invention consists of a configuous matrix inductive voltage divider (34), hereinafter divider (34), which is located between an electric power generator (3) and an electrical network (1). ) for supply to different users.

Physically, the divider (34) consists of a container in which the inductances (28 to 33) and disconnectors (5 to 22) are located, which connect with the control, acquisition and storage equipment (2), henceforth control equipment ( two).

The control equipment (2) connects with the input of the electric generator in its three phases through three probes (35) for voltage measurement and low voltage current that measure the voltage and electric current suffered by the electric generator when on the electrical network (1) the divider (34) performs a disturbance defined by the user. These probes (35) collect the voltage and current data which are sent to the control equipment (2) to perform the analysis of the disturbances that are made in the network (1) as well as their storage in a physical memory type SSD which will serve to subsequently perform the analysis of the behavior of the electric generator as a function of the received disturbance. On the other hand, the control device (2) also connects to the output of the electrical network (1) with the help of three probes (36) of voltage and current in low voltage that connect with each phase of the network (1) . In this way, the team monitors the changes that the electrical network undergoes before its arrival at the divider (34) and with this data modifications will be made in the configuration of the divider (34) to adapt the conditions of the network (1) to the disturbance that you want to perform. As in the previous case, the data collected by the probes (36) are stored in physical memories such as the SSD type not shown in the figures.

The bed of 6 inductances (28 to 33) are connected together in series or parallel with the help of a matrix of 18 disconnectors (5 to 22) divided into two groups:

to. 12 three-phase disconnectors (5 to 16). Each disconnector (5 to 16) connects to each of the 6 inductances (28, 33), 18 coils for the three phases, in the form of a cascade, in such a way that the inductance (28) connects through the disconnectors (5 and 11) to the inductance (29). In turn, the inductance (29) also connects with the inductance (30) through the disconnectors (6 and 12). This scheme is repeated until reaching the last inductance (33) which connects with the previous inductance (32) through the disconnectors (9, 15). Closing the disconnectors (6, 8, 11, 13 and 15) and opening the disconnectors (5, 7, 9, 12 and 14) connect the inductances (28 to 33) in series of all the inductances or part of them. In the same way, the inductances (28 to 33) can be connected in parallel by modifying the arrangement of the disconnectors, in addition, of hybrid configurations formed by part of them in parallel and the rest in series. The configuration in series, parallel or hybrid, allows to get up to 81 specific and different short-circuit currents for the same generator. This solution entails a technical improvement since with 6 coils it is possible to obtain enough configurations to test power generators without physically modifying the equipment and allowing great accuracy in the voltage level of the gap.

b. 6 disconnectors (17 to 22). Each disconnector (17 to 22) connects each of the 18 coils of the inductance (28 to 33) with each phase of the network that connects with the generator (3). In the case of no transformer module, the connection will be at low voltage. The configuration of the openings and closures of these disconnectors (17 to 22) allows obtaining the impedance point where the test voltage is to be obtained. That is, divide the total impedance of Short circuit in two impedances: impedance in series and impedance in parallel. In this way, the impedances are not exclusively parallel series or impedances since any impedance can be part of the parallel part or of the serial part, which allows to take advantage of a more efficient way, reducing the number of impedances and consequently the size and equipment weight.

In addition, with the help of 5 switches (23 to 27) the type of hole to be made is configured, and with the short-circuit switch (23) the holes are made. For this, the short circuit switch (23) connects with the three phases of the network of the disconnectors (10 and 16) that connect with the inductor (33). Each of the phases of the switch (23) connects to a different switch (24, 25 and 26) in such a way that the switch (24) corresponds to the phase A, that the switch (25) corresponds to the phase B and that the switch (26) corresponds to phase C.

Subsequently, the switches (24, 25 and 26) connect in a three-phase manner with the phase switch (27) that connects with the neutral of the network (1). In this way, the three switches (24, 25 and 26) are in parallel. By means of four switches (24 to 27) coupled to each phase and to the neutral, the type of hole is selected as explained above.

To carry out the configuration of the equipment it is necessary to close the switch (4), in addition to having the switch (17) closed which will serve as a by-pass between the network (1) and the generator (3). Once this is done to configure the divider (34) it is necessary to indicate the short-circuit current, which will serve to select the configuration of inductances (28 to 33) to be used and the connection between them by means of the switches (5 to 16). ), it is also necessary to indicate the test voltage level, which is used to configure the switches (17 to 22), the type of gap, which is used to configure the switches (24 to 27), and the length of the gap, which serves to configure the opening and closing maneuvers of the switch (23). Once the configuration has been completed, the switch (17) will open, if necessary, to perform the hole maneuver, switch operation (23) will be enabled, the gap being made and the equipment returned to the by-pass state by closing the switch ( 17) waiting for another hole or configuration change to be made.

For the realization of multiple gaps it is necessary to indicate the number of maneuvers to the switch (23) and the time between them, the switch (23) being unique or with several in parallel to allow a greater speed of response. For the realization of step gaps, you have to configure the two or more configurations that you want to test and the time between maneuvers.

Figure 2 shows a variant consisting of installing a set of two transformers (40, 43) before the input and output of the divider (34). At the outlet of the network (1), after the coupling of the probes (37), a switch (39) type disconnector medium voltage automatic connects the three phases with the transformer (40), which adapts the input voltage to the divider (34). The connection to the divider (34) is made in the three phases and the neutral through the disconnectors (4 to 16) coupling to the inductances (28 to 33). On the other hand, the three output phases of the divider (34) are coupled to a star configuration switch (41) to the transformer (43) low voltage side and a triangle configuration switch (42) to the transformer (43) side of the transformer. low voltage. The generator (3) is coupled to the transformer (43) through an automatic medium voltage switch (44) that is located before the probes (38) that measure the voltage and current in the generator (3).

The set of the two transformers (40, 43) makes it possible to adjust the input and output voltage levels of the divider (34) and thus establish the conditions of the disturbance suffered by the generator (3), with the transformer (40) which reduces the voltage of medium or high voltage to 690 V. The transformer (43) raises the voltage of 690 V to the level of medium or high voltage in the network and also through the switches (41) and (42) can be configure the two-phase type C holes when the connection is star, with switch (41) closed, or two-phase holes type D when the connection is in a triangle, switch (42) closed.

The control equipment (2) connects with the input of the electric generator (3) in its three phases through three probes (38) measuring voltage and current in high voltage that measure the voltage and electric current suffered by the electric generator (3) when the divider (34) and the transformer module (40, 43) perform a user-defined disturbance. On the other hand, the control device (2) is also coupled to the output of the electrical network (1) with the help of three probes (37) of voltage and current in high voltage that connect with each phase of the network (1). ). In this way, the team monitors the changes that the electrical network undergoes before its arrival at the transformer (40) and divider (34) and with this data it will be possible to make modifications in the configuration of the transformer module (40, 43) and divisor (34) to adapt the conditions of the network (1) to the disturbance that you want to perform. These probes (38) collect the voltage and current data which are sent to the control equipment (2).

Figure 3 shows the variant consisting in coupling between the generator (3) and the divider (34) a module (75) composed of three banks of capacitors (63 to 65) and 8 banks of resistors (66 to 73) before the splitter (3. 4). In this case the probes (74) of voltage measurement and low voltage output current of the control equipment (2) are coupled to the generator input (3) while the other measurement probes (not shown in the figure) for the network (1) they are coupled directly to the network (1). Each of the resistance banks (66 to 73) is composed of a resistance per phase that is coupled in star to each of the phases that connects the divider (34) with the generator (3) through a series of resistance switches (49 to 56). The three banks of capacitors (63 to 65) are coupled to each of the phases of the network that connects the divider (34) with the generator (3) through a first disconnector (46 to 48) and two different sets of disconnectors (57 to 62) that allow the star or triangle configuration of each of the capacitor banks (63 to 65). The disconnectors (57 to 59) allow the triangular configuration and the disconnectors (60 to 62) the configuration in star, being the relation in the impedance that exists between the capacitor bank connected in triangle and star of 3.

With the help of the module (75) the anti-island test is carried out. For this, the modules (75) and the divider (34) are configured so that the apparent power independent of inductances (28 to 33) and capacitors (63 to 65) is at least 2 times the apparent power of the electric generator (3). ) to be tested, the reactive energy consumption of the network (1) being less than 1% of the apparent power of the equipment to be tested. In turn, the resistance banks (66 to 73) must be configured so that the active power consumed is the same as the active power generated by the electrical generator (3) to be tested. Once the configuration has been made, in this condition of active and reactive power null in the network (1), the switch (4) will open, leaving the generator (3) connected to the divider assembly (34) and module (75) in the mode of operation. island. Once the test has been carried out, the switch (4) will be closed again while waiting for another test or configuration change.

Figure 4 shows the variant consisting in coupling between the generator (3) and the divider (34) a module, the third variant, which consists of coupling to the divider (34) a module OVRT (79) composed of a three-phase bank of two coils coupled (77 and 78) in air together with the associated disconnectors (76), with the coupling value M = 8X1. The coil (77) is connected between the switch (23) and the phase switches (24 to 25) respecting the phases. The coils (78) are connected between the switch (17) and the generator (3) having a common point of connection with the switch (76). The overvoltage is carried out by passing the short-circuit current through the coils (77), which are magnetically coupled to the coils (78) in which a voltage is induced which, added to the network voltage (1), will produce a controlled overvoltage value in the generator (3). The possible combinations of the inductances (28 to 33) with the help of the disconnectors (5 to 16) and (17 to 22) and switches (24 to 27) allow to obtain 403 different configurations, producing 2,821 different surges. These combinations allow tests on generators from OkW up to 8,000kW without the need to change any component in its standard version.

To make the configuration of the equipment it is necessary to close the switch (4), in addition to having the switch (76) and (17) closed that will serve as a bypass between the network (1) and the generator (3) once this is done to configure the divider (34) it is necessary to indicate the short circuit current, which will serve to select the configuration of inductances (28 to 33) to be used and the connection between them by means of the switches (5 to 16), it is also It is necessary to indicate the test voltage level, which is used to configure the switches (17 to 22), the type of gap, which is used to configure the switches (24 to 27), and the length of the gap, which serves to configure the opening and closing maneuvers of the switch (23). Once the configuration is completed, the switch (76) and (17) will open, if necessary, to carry out the overvoltage maneuver, the switch operation will be enabled (23), the overvoltage will be carried out and the device will be returned to the by-pass state closing the switch (76) and (17), waiting for the realization of another overvoltage or configuration change.

For the realization of multiple overvoltages it is necessary to indicate the number of maneuvers to the switch (23) and the time between them. Being the switch (23) unique or with several in parallel to allow a greater speed of response. For the realization of step surges, the two or more configurations that one wishes to test and the time between maneuvers must be configured. Figure 5 shows a variant that simulates the island effect in an electrical system based on coupling to the divider (34) the module (75) composed of capacitors (63 to 65) and resistors (66 to 73). The transformer module (45) connects in parallel with the divider (34) and the module (75) as follows:

«The connection of the transformer (40) to the divider (34) is made in the three phases and the neutral coupling the output of each phase of the transformer (34) to the disconnectors (4 to 16). The three output phases of the divider (34) are coupled to a star configuration switch (41) or to a triangle switch (42) to the low voltage side transformer (43)

«The connection of the transformer (43) with the module (75) is made in the three phases (it does not include the neutral) by coupling the output of the module (75) with the star configuration switch (41) or the triangle configuration switch (42).

Figure 6 shows a further variant that together with the matrix inductive voltage divider (34) and the OVRT module (79), serves to perform overvoltages of an electrical system that is connected to the transformer module (45). The transformer module (45) connects in parallel with the divider (34) and the OVRT module (79), as follows:

• The connection of the transformer (40) to the divider (34) is made in the three phases and the neutral coupling the output of each phase of the transformer (34) to the disconnectors

(4 to 16). The three output phases of the divider (34) are coupled to a star configuration switch (41) or to a triangle switch (42) to the low voltage side transformer (43).

• The connection of the transformer (43) with the OVRT module (79) is made in the three phases by coupling the output of the module (79) with the star configuration switch through the disconnector (41) or the disconnector in delta configuration through the disconnector (42).

• The connection of the transformer (43) with the module (79) is made in the three phases (it does not include the neutral) by coupling the output of the module (79) with the star configuration switch (41) or the triangle configuration switch (42).

Finally, figure 7 shows the most complete variant consisting in that next to the matrix inductive voltage divider (34) and the OVRT module (79) to which is added the module (75) composed of capacitors (63 to 65) and resistors (66 to 73). This is the most general case and serves to perform all the variables previously exposed. The transformer module (45), connects in parallel with the divider (34), the module (75) and the OVRT module (79), as follows:

«The connection of the transformer (40) to the divider (34) is made in the three phases and the neutral coupling the output of each phase of the transformer (34) to the disconnectors (4 to 16). The three output phases of the divider (34) are coupled to a star configuration switch (41) or to a triangle switch (42) to the low voltage side transformer (43).

· The connection of the transformer (43) with the OVRT module (79) is made in the three phases by coupling the output of the module (79) with the star configuration switch through the disconnector (41) or the disconnector in delta configuration through the disconnector (42). Figures 8, 9 and 10 show the diagram of phases that occur in the holes. Figure 8 corresponds to isolated three-phase balanced voltage gaps type A where the three phases (85, 87 and 89) have the same value in amplitude and the phase angle does not change showing (86, 88 and 90). Figure 9 corresponds to isolated biphasic voltage gaps type C where two of the phase voltages (87, 89) undergo changes in their amplitude and phase angle shown as (88 and 90) being able to choose between AB, AC, BC and Figure 10 shows a biphasic voltage gap isolated type D, where two of the phase voltages (87 and 89) undergo changes in their amplitude and phase angle passing to the phases (88 and 90) being able to choose between the combination of phases AB, AC, BC with the help of the transformer module.

Figures 11, 12 and 13 show an example of a double hollow, an example of a step hollow, originated with the device of the present invention and an example of isolated balanced three-phase overvoltages. They are overvoltages where the three phases have the same amplitude value and the phase angle does not change. Originated with the device of the present invention.

As shown in Figures 14 and 15, the divider (34) is mounted in a standard container (80) 20 feet long (6,096 m) for ease of transportation and location. The container is closed, figure 14, by metal walls except two openings (81 and 82) that allow the output of the voltage and input current measurement probes (36) and the voltage and output current measurement probes (37). The structure (84) of the container (80) allows adjustment and arrangement of the divider elements (34) therein. The structure (34) rests on 4 flat legs (83) that give stability to the container (80), and therefore to the divider (34), when this is located near the generator (3). The distribution of the elements of the divider (34) inside the container (80) is:

• The disconnectors (5 to 22) of impedance configuration to be connected to the coils of the inductances (28 to 33), are arranged in three columns supported by the structure (84) at one longitudinal end of the container (80) in such a way that the disconnectors (5 to 10), the disconnectors (11 to 16) and the disconnectors (17 to 22) are located in three different columns.

• The bed of 6 inductances (28 to 33) composed of 18 coils is distributed in the center of the container (80) along two rows composed of three columns in which each column houses 3 of the coils of the 6 inductances ( 28 33).

• The control equipment (2), the main switch of the divider (4) as well as the short-circuit switch (23), the three phase switches (24 to 26) and the neutral switch (27) are located in the other longitudinal end of the container and with the help of the structure (84).

The connection between the different elements of the divider (34) is made through a network (85) internal to the divider that is distributed vertically and horizontally along the container (80).

Industrial application

This invention is of industrial application in the sector of the technique related to generators of electrical energy such as wind turbines, photovoltaic energy, etc.

Claims

Device for generating network disturbances to a generator or electrical load (3), hereinafter generator (3), characterized by comprising a configurable inductive matrix voltage divider (34), hereinafter divider (34), located between a generator (3) and an electrical network (1), which comprises:

or a control device (2) connected to the input of the generator (3) in its three phases through three probes (35) for measuring voltage and current and also connected in the three phases of the output of the electrical network ( 1) through three probes (36) of voltage and current,

or a bank of 6 inductances (28 to 33) formed by 3 groups, one per phase, with a total of 18 coils connected to each other through a matrix of 18 disconnectors (5 to 22) divided into two groups:

• 12 three-phase disconnectors (5 to 16) in which each disconnector (5 to 16) connects to each of the 18 coils of the 6 inductances (28 to 33) in the form of a cascade,

• 6 disconnectors (17 to 22) in which each disconnector (17, 22) connects each of the 18 inductance coils (28 to 33) with each phase of the network that connects with the generator (3),

or 5 coupled switches (23 to 27) in which the first switch (23) is short-circuit and couples the three network phases of the disconnectors (10 and 16) that connect to the inductor (33) and in parallel each of the switch phases (23) with the switches (24, 25 and 26), the switches (24, 25 and 26) being connected in a three-phase manner with the phase switch (27) that connects with the neutral of the network.

2. Device for generating network disturbances to a generator (3) according to claim 1 characterized in that

• the value of the first inductance (28) is equal to the last inductance (33), the second and fifth inductances (29, 32) have the same value and each of these inductances (29, 32) is four times the value of the first inductance (28) and the value of the inductance (30) is equal to the value of the inductance (31) being the value of the inductance (30) and the inductance (31) equal to 8 times the value of the inductance (28), • the value of the 12 three-phase disconnectors (5 to 16) is equal to the value of the rated current,

• the value of the coupled switches (24 to 27) is equal to 1/3 of the rated current and the value of the coupled switch (23) is equal to the rated current of the device.

Device for generating network disturbances to a generator (3) that according to claim 1 characterized by coupling a set of transformers (40, 43) before the input and output of the inductive divider (34) where:

• at the outlet of the electrical network (1), a switch (39) type medium voltage automatic disconnector connects the three phases with the transformer (40) input voltage adapter to the divider (34),

• the transformer (40) is coupled in the three phases and the neutral through the disconnectors (4 to 16) to the inductances (28 to 33) of the divider (34),

• the three output phases of the divider (34) are coupled to a star configuration switch (41) and a triangle configuration switch (42) to the transformer (43) at low voltage,

• the generator (3) is coupled to the transformer (43) through an automatic medium voltage switch (44) that is located between the probes (38) and the transformer (43),

and in that the probes (38) of the control equipment (2) connect to the generator input (3) in its three phases and the probes (37) are coupled to the output of the electrical network (1) in its three phases .

Device for generating network disturbances to a generator (3) according to claim 3, characterized in that the transformer (40) adapts the network voltage (1) from a maximum of 35,000 V to 690 V.

Device for generating network disturbances to a generator (3) according to claim 1 characterized by coupling between the generator (3) and the divider (34) a capacitor and resistor bank module (75), hereinafter module (75), which It comprises three banks of capacitors (63 to 65) and 8 banks of resistors (66 to 73) where: • each of the resistor banks (66 to 73) is composed of one resistance per phase coupled in star to each of the phases that connects the divider (34) with the generator (3) through a resistance switch ( 49 to 56),

• the three banks of capacitors (63 to 65) coupled to each of the network phases that connects the divider (34) with the generator (3) through a first disconnector (46 to 48) and two different sets of disconnectors (57 to 62), with the configuration of the disconnectors (57 to 59) in triangle and the configuration of the disconnectors (60 to 62) in star and because the impedance relation between the bank connected in delta and star is equal to three, and because the probes (74) for voltage measurement and low voltage output current of the control equipment (2) are coupled to the generator input (3).

Device for generating network disturbances to a generator (3) according to claim 1 characterized by coupling to the divider (34) an overvoltage module (OVRT, 79) comprising a three-phase bank of two sets of coils (77 and 78) coupled in air, the three coils (77) being connected to the switch (23) and to each of the switches (24 to 25), one per phase, and because the coils (78) connect to the switch (17), the generator (3) and the switch (76). Device for generating network disturbances to a generator (3) comprising a divider (34) according to claim 3 characterized by

• coupling between the transformer (43) and the divider (34) an OVRT module (79) comprising a three-phase bank of two sets of coils (77 and 78) coupled in air, the three coils (77) being connected to the switch (23) and with each of the switches (24 to 25), one per phase, and why the coils (78) connect with the switch (17) and with the star configuration switch (41) or the disconnector in triangle configuration (42) of the transformer (43) and the switch (76),

• Parallel between the transformer (43) and the divider (34) a bank of capacitors and resistors (75) comprising three banks of capacitors

(63 to 65) and 8 resistor banks (66 to 73) before the divider (34) where: or each of the resistor banks (66 to 73) is composed of a resistance per phase that is coupled in star to each of the phases that connects the divider (34) with the transformer (43) through resistance switches (49 to 56),

or each capacitor bank (63 to 65) is coupled to each of the network phases that connects the divider (34) with the transformer (43) through a first disconnector (46 to 48) and a set of disconnectors of configuration in triangle (57 to 59) and another set of disconnectors of star configuration (60 to 62).

Device for generating network disturbances to a generator (3) according to claim 7, characterized in that each capacitor (63 to 65) has a value such that connected in parallel with an impedance of equal value to the first inductance (28) resonates with it at the frequency of 50 or 60 Hz, the reactive power consumption being zero and

• the value of the three capacitors (63 to 65) being identical and equal to / V (f ^A 2 * Impedance of the inductance (28)), when the connection is star,

• the value of the three capacitors (63 to 65) being identical and equal to three times the value when the connection is in a triangle,

• the value of the first and second resistance (66, 67) being equal, the value of the third and fourth resistance (68, 69) equal and with a value of two times of the first resistance (66), the value of the fifth and sixth resistance (70, 71) equal and with a value of four times of the first resistance (66) and the value of the seventh and eighth resistance (72, 73) equal and with a value of eight times of the first resistance (66) the last resistor (73) being able to consume 1/30 of the nominal power of the equipment.

9. Device for generating network disturbances to a generator (3) comprising a divider (34) according to claim 7 characterized in that the coupling value of the two sets of coils (77, 78) is equal to 8 times the value of the impedance of the inductance (28).

Device for generating network disturbances to a generator (3) according to claim 7, characterized in that all the switches of the device are mechanical and in that the control equipment (2) comprises: • a control system through a programmable logic controller (PLC) and a man-machine interface (HMI),

• a data acquisition system,

• a storage system of at least 1TB

and because the voltage probes are voltage-to-voltage type Hall-effect transducers with a sampling frequency of at least 100,000 samples / second and 16 bits of resolution and the current probes are Rogowski-type current-to-voltage transducers with a frequency sampling at least 100,000 samples / second and 16 bits of resolution.

Device for generating network disturbances to a generator (3) according to claim 10, characterized in that the power of the generator (3) is between 0 kW and 8,000 kW.

Device for generating network disturbances to a generator (3) according to claim 1, characterized in that the divider (34) is installed in a closed container (80) that includes two openings (81 and 82) of exit of the measuring probes of voltage and current (36 and 37) and because the structure (84) rests on 4 flat legs (83) and because:

• the disconnectors (5 to 22) are arranged in three columns supported by the structure (84) of one longitudinal end of the container (80) with the disconnectors (5 to 10), the disconnectors (11 to 16) and the disconnectors (17) to 22) (28 to 33) located in three different columns,

• the bank of 6 inductances (28 to 33) composed of 18 coils are distributed in the center of the container (80) along two rows composed of three columns in which each column houses 3 of the coils of the 6 inductances ( 28 to 33),

• the control equipment (2), the main switch of the divider (4) as well as the short-circuit switch (23), the three phase switches (24 to 26) and the neutral switch (27) are located in the other longitudinal end of the container with the help of the structure (84),

and in that the connection between the different elements of the divider (34) is made through a network (85) internal to the divider (34) distributed vertically and horizontally in the container (80) and because the container (80) is standard type of 6.096 m in length.

13. Method for generating network disturbances to a generator (3) comprising a device according to claim (7) characterized by defining in the control equipment (2) the configuration of:

• the 12 disconnectors (5 to 16) of configuration of impedances connecting to each other to the 6 inductances (28, 33) in series, parallel or combination of both obtaining 81 different short-circuit currents,

• the 6 disconnectors (17, 22) for selecting the impedance level by configuring the test voltage and selecting in the control equipment (2) the impedance point for the test voltage,

• the four switches (24 to 27) coupled to each phase and to the neutral by selecting between the following hole types:

or a balanced three-phase voltage gap type A when closing the 3 switches (24 to 26),

or an isolated two-phase voltage dip type C and D when closing the switches

(24 to 26) of 2 in 2,

or a single-phase voltage gap to closed ground type B by closing one of the phase switches (24 to 26) with the neutral switch (27), or a two-phase voltage gap to ground type E when closing the phase switches ( 24 to 26) of 2 in 2 with the neutral switch (27), and because the combinations of inductances (28 to 33) with the disconnectors (5 to 22) produce 4,030 different voltage gaps both in the type of gap and in its depth being configurable the amplitude of tension with an accuracy of 0.5%, the duration of the gaps between 50 ms to 10 seconds and the short circuit current.

Method for generating network disturbances to an electrical generator (3) according to claim 13, characterized in that when the switch (41) is closed with a star connection, it forms two-phase voltage gaps type C and when the switch (42) is closed, it forms voltage gaps biphasic type D.

15. Method for generating network disturbances to a generator (3) according to claim 13, characterized in that the configuration of the anti-island test is performs defining in the control equipment (2) an apparent power independent of inductances (28 to 33) and capacitors (63 to 65) of at least 2 times the apparent power of the electric generator (3) being the reactive power consumption of the network (1) less than 1% of the apparent power of the electric generator (3) and because the resistor banks (66 to 73) are configured so that the active power consumed is the same as the active power generated by the electric generator ( 3), and because once the configuration for active and reactive power zero in the network (1) has been defined, the switch (4) is opened connecting the generator (3) to the set (34) and (75) in the mode of operation. island and because once the test has been carried out, the switch (4) is closed again.

16. Method for generating network disturbances to an electrical generator (3) according to claim 13, characterized in that the configuration of the overvoltage test with the OVRT module (79) is carried out:

• closing the switch (4) and switches (76) and (7),

• defining in the control equipment (2) the short-circuit current for the selection of inductance settings (28 to 33) and connection between them by means of the switches (5 to 16),

• defining in the control equipment (2) the voltage level of the configuration test of the switches (17 to 22), the type of configuration space of the switches (24 to 27), and the duration of the configuration gap switch opening and closing maneuvers (23),

• opening the switch (76) and (17) and, if necessary, enabling the switch operation (23),

and because the equipment returns to the by-pass state by closing the switch (76) and (17).

Method for generating network disturbances to an electrical generator (3) according to claim 16, characterized in that the overvoltage test is carried out by passing the short-circuit current through the coils (77), these being magnetically coupled to the coils (78), resulting in 403 different configurations and producing 2,821 different overvoltages by the combinations of the inductances (28 to 33), disconnectors (5 to 16) and (17 to 22) and switches (24 to 27).