Patent Application
20080068119
The characteristic details of the present invention are described in the following paragraphs, together with the figures related to it, in order to define the invention, but not limiting the scope of it.
At least one main winding 80 is concentrically wound around the central column 30. In the electric reactor the controlled reactive power 10, the main winding 80 may be formed by various concentric layers of turns.
The magnetic core 20 consists of at least one generator of magnetic distortion field 90 that may be formed by a first pair of orifices 100 and a second pair of orifices 110 that pass through the thickness of the magnetic core 20, whether through a column or a yoke of the mentioned structure of a window type so that both pairs of orifices are generally adjacent. The term “orifice”, as used in the context of the present description means an opening, nozzle or orifice that may have any form and passes through an solid part of the magnetic core 20. In the first pair of orifices 100, a first control coil 120 is found wound up, and a second control coil 130 is wound in the second pair of orifices 110. In the three-phase case, it is necessary that each generator of magnetic distortion field 90 is located in a position relative to the magnetic core 20 so that it allows maintaining the magnetic equilibrium of the latter to assure reactive powers of consumption for each balanced phase.
A main current passes through the main winding 80, inducing a main magnetic flow in the magnetic core 20. In order to control the reactor's reactive power of consumption, the main magnetic flow is controlled when an alternate or continual control current passes simultaneously through each generator of the magnetic distortion field 90 to form fields of magnetic distortion of equal intensity in the magnetic core 20, so that each magnetic distortion field combines with the main magnetic flow originating a distortion in the latter while obtaining a resulting magnetic field.
In each generator of a magnetic distortion field 90, the control current is simultaneously provided to the first control coil 120 and to the second control coil 130 through some means to provide control current (not shown) that are electrically connected to these control coils. This control current is provided when a variation is detected in the required consumption of reactive power that varies in relation to the necessities of reactive power compensation of the system to which said reactor is connected. Thus, the reactive power of consumption makes itself corresponding to a current intensity that feeds each of the generators of magnetic distortion fields 90 to form the magnetic distortion fields in order to obtain the desired controlled reactive power of consumption.
From the perspective of the magnetic core 20, there is at least one generator of magnetic distortion field 90 formed by a first pair of orifices 100 and a second pair of orifices 110 that pass through the thickness of the magnetic core 20, through a column or a yoke, or through a combination of both. In the first pair of orifices 100, a first control coil 120 is wound with one or more spirals, while in the second pair of orifices 110 a second control coil 130 is wound with one or more spirals.
A main magnetic flow 140 is induced in the magnetic core 20 by the main current circulating in the primary winding (not shown). When a variation in the reactive power occurs in the node where the reactor and/or a variation in the profile of the electric tension of said node occur, then the means to provide control current (not shown) provide simultaneously an alternate or continual control current to each of the generators of magnetic distortion fields 90, supplying simultaneously control current to the first control coil 120 and to the second control coil 130. Thus, the first control coil 120 generates a first magnetic control flow 150 in the magnetic core 20, while the second control coil 130 generates a second magnetic control flow 160 in the opposite direction of the first magnetic control flow 150. Both magnetic control flows 150 and 160 forming a magnetic distortion field 170 in the magnetic core 20 that combine with the main magnetic flow 140. The intensity of the control current supplied to the generators of magnetic distortion fields 90 correspond to the detection of the reactive power of consumption required in relation to the profile of the electric voltage node of the power system to which the reactor is connected.
Each of the magnetic distortion fields 170, when combined with the main magnetic flow 140 act in an analogue or equivalent manner to the function of the physical air gap in the magnetic core 20, but with the difference that the size of the magnetic distortion field 170 varies according to the intensity of the control current supplied to the generator of the magnetic distortion field 90, specifically to the first control coil 120 and to the second control coil 130. Therefore, logically, it would be like having the function of an air gap of a variable size according to the operation requirements of the reactor of controlled reactive power 10.
It is important to mention that the generators of magnetic distortion fields 90 must be connected in series or parallel in order to generate the magnetic distortion fields 170 of the same intensity, and located in a position relative to the magnetic core 20 so that the magnetic equilibrium of the latter may be maintained to ensure balanced reactive powers of consumption.
The presence of a magnetic distortion field 170 in a magnetic circuit provokes changes in the reluctance of that field itself. At a bigger amount of and/or intensity of the magnetic distortion field 170, the change in reluctance increases. Therefore, in a controlled reactive power reactor 10, in the presence of a change in reluctance, the main current of the main winding will vary to maintain the main magnetic flow 140 constant. Based on the principle of magnetic stability of an electromagnetic system, and with a variation in the supplied currents to the control windings, a variation in the magnetic distortion is encountered. Therefore, there is a variation in the core reluctance. This originates a variation in the main current to maintain the main magnetic flow constant. Experienced variation of the main current is translated into a variation of the consumed reactive power, which in this case is the variable of the required control for a controlled reactive power reactor according to the present invention.
The above described is expressed mathematically in the following:
Where:
As an example, because of the increase in reluctance, the primary winding current (IP) will increase to maintain the main magnetic flow (φ) constant (cte).
Such increment in the primary winding current (IP) is translated as an increment in the consumption of reactive power (Q); while a decrease in the primary winding current (IP) is reflected as a decrease in the reactive power consumption (Q) of the reactor.
Turning now to
Next, in step 190, the required reactive power of consumption in relation to the requirements of reactive voltage compensation is detected, which demands the voltage system to which the controlled reactive electric voltage reactor 10 is connected, to proceed in step 200 and generate at least one magnetic distortion field 170 in the magnetic core 20 (where in case of a three-phase reactor the magnetic equilibrium is controlled to ensure the balanced reactive consumption voltages). Thus, each magnetic distortion field 170 combines with the main magnetic flow 140, generating a distortion in the latter. In this way the reactive consumption power of said reactor is accomplished, because as the current varies in the main winding, also the reactive voltage will vary, which is the desired control variable.
The magnetic distortion field 170 can be generated when supplying, in step 210, a control current, whether alternate or continual at an intensity that varies in relation to the detection of the reactive power of consumption required in relation to the profile of the electric node voltage of the power system to which the reactor is connected, to a first control coil 120 to generate a first magnetic control flow 150 over the magnetic core 20, where the first control coil 120 is wound in a first pair of orifices 100 in the magnetic core 20. Simultaneously, in step 220, said control current is supplied to a second control coil 130 to generate a second magnetic control flow 160 in the magnetic core 20, where the second control coil 130 is wound in a second pair of orifices 110 in the magnetic core 20 so that the second magnetic control flow 160 has an opposite direction to the first magnetic control flow 150, thus forming the magnetic distortion field 170 whose representation of magnetic field lines is shown in
An alternative embodiment of this invention, and with the purpose of maintaining the required safety redundancy in the reactor, consists in combining the use of generators of magnetic distortion and the structure of a central column of air gaps. So, in case of failure of the magnetic distortion generators, the central column of air gaps accomplishes its committed safety redundancy. In this case, the electric reactor of controlled reactive power may be formed in a very similar way to the reactor described in
In addition to the above, the magnetic core consists of at least one field generator of magnetic distortion that may be formed by a first pair of orifices and a second pair of orifices that pass through the thickness of the magnetic core, whether through an external column or a yoke of the mentioned structure of a window type. In another embodiment of the invention, the magnetic distortion generator may be located in one or more ferro-magnetic doughnuts of the central column of air gaps.
As to the method to adjust the reactive power of an electric reactor described with the use of the safety redundancy according to the former paragraphs, it is similar to the method described in
Control over the magnetizing curves allows control of the saturation level, and as a consequence the harmonics in the current and electric voltage signals. This is, as the saturation level increases, the contents of the harmonics increases, and vice versa.
Although the invention has been described with reference to specific embodiments, this description in not meant to be constructed in a limited sense. The various modifications of the disclosed embodiments, as well as alternative embodiments of the invention, will become apparent to person skilled in the art upon reference to the description of the invention. It is, therefore, contemplated that the appended claims will cover such modifications that fall within the scope of the invention, or their equivalents.
| Number | Date | Country | Kind |
|---|---|---|---|
| NL/A/2006/000065 | Sep 2006 | MX | national |
