HK1118388A

HK1118388A - Apparatus and method for increasing efficiency of electric motors

Info

Publication number: HK1118388A
Application number: HK08109422.1A
Authority: HK
Inventors: Gerald Goche
Original assignee: Miraculous Motors Corporation
Priority date: 2005-06-01
Filing date: 2006-05-31
Publication date: 2009-02-06

Description

Apparatus and method for improving efficiency of electric machine

Cross Reference to Related Applications

This application claims priority to co-pending U.S. patent application No.10/602,966 filed 24/6/2003 by the same inventor, which in turn relates to french patent application No. 0207820000 filed 25/6/2002, which is now entitled french patent No. fr2841404.

Technical Field

The present invention relates to an electric machine and a synchronous generator, and in particular it relates to an electric machine or generator capable of operating at very high efficiency over a wide range of loads.

Background

Single phase ac motors are commonly used for low horsepower applications. Which can range from very little horsepower to approximately ten horsepower. A three-phase motor is typically used when horsepower is required in excess of ten horsepower.

U.S. patent No.4,446,416A entitled "polymeric electric motor Controlled Magnetic Flux sensitivity" issued to Wanlass at 5/1 in 1984 discloses a stator core Having a main winding and additional control windings. The flux density in a multiphase motor is optimized by controlling the flux density in the stator core. In particular, the main multi-phase stator winding wound on the core includes a plurality of windings, wherein each winding represents a phase. A capacitor is connected in series to each winding. The capacitor can reduce the reactive power.

An additional Motor winding technique is also disclosed in german patent application No.2508374 entitled "Single phase indication Motor" issued 9/1976 to Wen. Wen discloses a single phase motor with two start windings to increase the start capacitor voltage. Wen also discloses a single phase induction motor having two sets of start windings to provide better operating power factor and improved starting torque.

The Wanlass and Wen motors, like all motors known so far, operate at maximum efficiency at full load and are inefficient at low load conditions. Accordingly, the conventional motor may have a power factor greater than 0.90 during a full load condition and a power factor of 0.50 or less at low loads.

The utility gives a power factor that is an exact inverse percentage of the energy provided to any motor. A motor operating at 0.70 power factor uses thirty percent (30%) more amps than a motor operating at full power factor (0.999 or 1.00). As a result of the need to replenish the amperage demand, the generator supplying the energy may be overloaded and will be simultaneously diverted to the drive (diesel or turbine), which will require more energy to meet the new demand. The new demand (in kilowatts) is the same as the original demand. The only change is in the power factor. Therefore, it is not desirable to use a motor that cannot operate at a high power factor under all loads.

There is therefore a need for a motor that can operate at high power factor under all loads. However, since low efficiency under low load is an inherent characteristic of the motor, it has been conventionally thought for many years that the motor will always operate at a reduced efficiency when the load applied thereto is reduced. It is impossible to obtain a power factor in the range of 0.90 and above in a low load state.

When supplied to consumers using low power factor (P/F) conventional motors, then any power producer suffers a loss in its production. Greater losses are experienced if the motor is often used at low duty cycles (from no load to seventy-five percent (75%) load) or if the motor is fed by a v.f.d (variable frequency drive). When the motor reduces speed by reducing frequency, it automatically reduces the power factor.

For example: a motor (a) drawing thirty (30) amps at four hundred sixty (460) volts at 0.88 power factor will consume 21.03KW (30 amps x 460 volts x 1.732 x 0.88P/F).

Another motor (B) of the same h.p. running at an average P/F of 0.68 will also consume 21.03 KW. While the amperage increased to 38.83 amps (38.83 amps x 460 volts x 1.732 x 0.68P/F).

The KW consumed by motor (a) is the same as the KW consumed by motor (B). This means that the supply motor (B), the electric company will have to have its generator produce 29.4% more amps than the supply motor (a). Generators that generate electricity are typically driven by diesel engines or steam turbines. Current is a factor in both loaded and unloaded generators, so the direct result of the above comparison of motors is that 29.4% more energy is consumed for motor (B) than motor (a) (diesel fuel, coal, etc.) to produce the same 21.03 KW.

It can be concluded from this that the owner of the electric motor (B) should pay more for its 21.03KW than the owner of the electric motor (a). Alternatively, the owner of the motor (B) may be required to exchange said low power factor motor for a high power factor motor.

What is needed, then, is an improved motor to increase the power factor of the motor so that less energy is required to perform a given task relative to a conventional, low power factor motor. For example, if the power factor can be increased to 0.98, the current will drop to 26.93 amps. Multiplying the amperage by 460 volts and 1.732 and 0.98P/F yields 21.03 KW. Note that the current draw (draw) is 38.83 amps at a power factor P/F of 0.68, 30.0 at a P/F of 0.88, and 26.93 amps at a P/F of 0.98.

However, in view of the prior art generally considered in forming the present invention, it is not obvious to one of ordinary skill in the art of electric machines how to increase the power factor of an electric machine sufficiently.

Disclosure of Invention

The invention comprises an inventive method for increasing the efficiency of an alternating current machine over its entire operating range, i.e. from no load to full load. The very novel step comprises the step of selecting a first wire diameter (wire size) for the first conductor and a second wire diameter (wire size) for the second conductor such that the first wire diameter is greater than the second wire diameter. The first conductor is wound to form a main winding and the second conductor is wound to form an additional winding. The number of turns of the additional winding is at least equal to half the number of turns of the main winding and may be equal to but not greater than the number of turns of the main winding. The capacitor is electrically connected in series with the additional winding. The additional winding and the capacitor are then electrically connected in parallel with the first winding. The additional winding is connected in an opposite direction with respect to the main winding such that current in the first winding flows in a first direction and current in the additional winding flows in a second direction opposite to the first direction.

A main winding and an additional winding as well as a capacitor are provided for each phase of a single-or multi-phase motor.

In a three-phase motor, three of the main windings and three of the additional windings and capacitors are connected in a delta or star configuration (also referred to as a "Y" or "Wye" configuration).

To determine the capacitance value (in microfarads) of the capacitor in series with the additional winding, the current drawn by the ac motor at full load when the line voltage is supplied thereto is determined. This value (in microfarads) is obtained by multiplying the current drawn by the ac motor at full load by an empirical factor (constant) and dividing by the square of the line voltage.

The empirical coefficients fall within a range of from about 0.25 x 10⁶To about 0.30X 10⁶Within the range of (1).

The first and second wire diameters are selected such that the cross-sectional area of the first wire diameter is greater than the cross-sectional area of the second wire diameter by a ratio of about two-thirds (2/3) to one-third (1/3).

The step of winding the first conductor to form the main winding is preferably performed simultaneously with the step of winding the second conductor to form the additional winding. This winding of the additional winding is performed at least part of the time during which the step of winding the first conductor is performed.

The ac motor of the present invention operates at very high power factor under all load conditions. As used herein, the term "ac motor" includes single phase or multi-phase ac motors having at least three phases. The term also includes synchronous generators having at least two poles. For convenience, the following disclosure will be referred to as a motor, but it should be understood that the broader term "motor" as defined herein can be substituted for every reference to a motor.

The novel motor of the present invention includes a main winding that is nearly identical to a conventional motor. However, it differs in that an additional winding with a desaturation (de-saturation) function is also provided. Each additional winding is electrically connected in series with a capacitor. Each additional winding and capacitor is electrically connected in parallel with the main winding. It is noted that the additional winding is connected in reverse with respect to its associated main winding, so that the direction of current flow through the main winding is opposite to the direction of current flow through the additional winding. Furthermore, the current flowing through the main winding is out of phase with the reverse current flowing through the additional winding. A suitably sized capacitor allows for the precise phase shift required to perform the method of the present invention.

The total cross-sectional area of the wire used on each of the main and additional windings is respectively allocated to each winding according to a specific ratio. Specifically, the total cross-sectional area is defined as a whole, so that the cross-sectional area of the main winding is about two-thirds of the whole (2/3), and the cross-sectional area of the additional winding is about one-third of the whole (1/3).

The invention further includes a novel winding method for an ac electric machine. In particular, both windings of the machine are preferably completed at the same time in the same operation, as one step.

The invention also includes a method for calculating the value (in microfarads) of a capacitor connected in series with an additional winding. The value of the capacitor (in microfarads) is proportional to the actual full load current and inversely proportional to the square of the line voltage. Numerator multiplied by a factor of 0.25X 10⁶To 0.30X 10⁶A multiplier within a range or a constant.

A single phase electric motor according to the present invention includes first and second primary windings electrically connected to a primary common point and first and second primary bitlines of a line voltage. It further includes first and second additional windings electrically connected to the winding capacitor and the first and second potential lines in parallel with the first and second main windings. The first and second additional windings generate magnetic fields in opposite directions with their associated first and second main windings, respectively.

The start winding is electrically connected between a preselected line of the first and second potential lines and the start capacitor. A switch is electrically connected between the start capacitor and the preselected line of the first and second potential lines.

The cross-sectional area of the main winding of each of the first and second main windings is approximately twice the cross-sectional area of its associated first and second additional windings. Ratios of two-thirds to one-third (2/3-1/3) also apply to single-phase and multi-phase windings.

The present invention has additional aspects that not only improve the power factor of the motor but also reduce kilowatt consumption.

Drawings

For a fuller understanding of the nature and objects of the present invention, reference is made to the accompanying drawings, in which:

FIG. 1 is a diagram of a prior art single phase motor;

FIG. 2 is a diagram of a modified prior art single phase motor;

FIG. 3 is a diagram of a prior art three-phase delta configuration motor;

FIG. 4 is a diagram of a prior art three-phase star configured motor;

FIG. 5 is a diagram of a prior art delta configuration motor;

FIG. 6 is a diagram of a prior art star configuration motor;

FIG. 7 is a diagram of the prior art internal connections of the windings of a motor having four poles;

FIG. 8 is a diagram of a single phase motor according to the teachings of the present invention;

FIG. 9 is a diagram of a delta configuration three phase motor in accordance with the teachings of the present invention;

FIG. 10 is a diagram of a three-phase electric machine of star configuration in accordance with the teachings of the present invention;

FIG. 11 is a diagram of winding internal connections for four poles on a delta adjacent pole, three phase motor in accordance with the teachings of the present invention;

FIG. 12 is a diagram of a delta configuration motor in accordance with the teachings of the present invention;

FIG. 13 is a diagram of a delta configuration motor in accordance with the teachings of the present invention;

FIG. 14 is a diagram of a star (or Y) configuration motor in accordance with the teachings of the present invention; and

figure 15 is a diagram of a delta configuration motor in accordance with the teachings of the present invention.

Detailed Description

Referring to fig. 1, it can be seen that a prior art single phase motor is generally illustrated and designated by the reference numeral 10.

The single phase motor 10 includes a run winding 12, a start winding 14, and a run capacitor 16. When the operating speed is reached, capacitor 16 de-phases the start winding immediately after the start sequence. This does not improve the power factor of the motor 10. The current flowing through winding 14 flows in relation to winding 12 to determine the direction of rotation required for the application of the motor.

Single phase motors typically include a starting capacitor in series with a centrifugal switch or isolating relay (decoupling relay) that forms part of the starting winding circuit. Accurate sizing of the run capacitor in microfarads optimizes the efficiency of the motor, thereby enhancing starting torque, starting and running current, and temperature.

For example, fig. 2 schematically illustrates such an improved single phase motor, generally designated 10 a. The motor 10a includes a run winding 12, a start winding 14, a start capacitor 16, a centrifugal switch or isolation relay 18, and a run capacitor 20.

Fig. 3 illustrates a prior art three-phase motor having main windings 21, 23 and 25 arranged in a delta configuration. The respective incoming line voltages for the three phases are shown as R, S and T.

Fig. 4 illustrates a prior art three-phase motor having main windings 21, 23 and 25 arranged in a star configuration. The respective incoming line voltages for the three phases are shown as R, S and T. The center point of the star connection is denoted 0.

In prior art three-phase machines, the number of poles is determined by the speed required for a particular application. Internally connected star or delta configurations to deliver the torque, horsepower, and voltage internal correlations required for a particular application.

Fig. 5 shows a prior art improved three-phase delta configuration motor 30. The three main windings are denoted 21, 23 and 25 and the three additional windings are denoted 27, 29 and 31. The additional winding capacitors are shown at 33, 35 and 37 and the three-phase line voltage connections are shown at R, S and T.

The additional winding 27 is connected in series with a capacitor 33, and the additional winding 27 and the capacitor 33 are electrically connected in parallel with the main winding 21. The additional winding 27 is connected in the same direction as the main winding 21. Thus, the current flows through the main winding 21 and the additional winding 27 in the same direction. The capacitor 33 inverts the current flowing through the additional winding so that it is out of phase with the current flowing through the main winding 21. This reduces the reactive power of the machine and only improves the power factor at rated full load.

Windings 27, 29 and 31 have the same number of turns as windings 21, 23 and 25.

The additional winding 29 is connected in series with a capacitor 35, and the additional winding 29 and the capacitor 35 are electrically connected in parallel with the main winding 23. The additional winding 29 is connected in the same direction as the main winding 23. Thus, the current flows in the same direction through the main winding 23 and the additional winding 29. The capacitor 35 inverts the current flowing through the additional winding so that it is out of phase with the current flowing through the main winding 23. This reduces the reactive power of the machine and only improves the power factor at rated full load.

The additional winding 31 is connected in series with a capacitor 37, and the additional winding 31 and the capacitor 37 are electrically connected in parallel with the main winding 25. The additional winding 31 is connected in the same direction as the main winding 25. Thus, the current flows through the main winding 25 and the additional winding 31 in the same direction. The capacitor 37 inverts the current flowing through the additional winding so that it is out of phase with the current flowing through the main winding 25. This reduces the reactive power of the machine and only improves the power factor at rated full load.

Fig. 6 shows a prior art three-phase star-structured motor. The three main windings are denoted 21, 23 and 25 and the three additional windings are denoted 27, 29 and 31. The three additional winding capacitors are indicated at 33, 35 and 37 and the three-phase line voltage connections are indicated at R, S and T. The star centre point of the main winding is denoted OP and the star centre point of the additional winding is denoted OS. As with the delta configuration of fig. 5, each additional winding is electrically connected in series with its associated capacitor, and each additional winding and capacitor in series is electrically connected in parallel with its associated main winding. The additional winding is connected in the same direction as its associated main winding. Each additional winding has the same number of turns as its associated main winding.

Fig. 7 is a winding diagram of a prior art motor. It shows the winding spacing connections and shows four poles, each of which is represented in each phase A, B and C (four (4) poles for phase a, four (4) poles for phase B, and four (4) poles for phase C in the main winding Y and the additional winding V). The connection point in the line R is indicated as 40 for the main winding Y and 42 for the additional winding V. The line S is denoted 44 for the main winding Y and 46 for the additional winding V. In the line T is indicated 48 for the main winding Y and 50 for the additional winding V. Additional winding capacitors are shown as 52, 54 and 56. Note that the winding is a physically unbalanced pattern. The triangular connections 44 are non-uniform (uneven) with respect to the triangular connections 40 and 48.

In addition, the triangular connection 46 is non-uniform with respect to the triangular connection points 42 and 50. This physical imbalance affects the phase angle slip (slip) between the two windings relative to the direction of rotation (clockwise or counterclockwise) of the motor. This type of inter-winding connection affects the energy saving in one direction of rotation.

Applying the techniques of fig. 5, 6 and 7 to a conventional three-phase motor increases the overall copper density by approximately fifteen percent (15%), and divides the conventional winding into two separate windings on a half (1/2) scale.

Changing the conventional motor to the technique of fig. 5, 6 and 7 requires the following conditions:

increase the overall copper density by about fifteen percent (15%)

Splitting the conventional winding into two (2) separate windings in the proportion of 1/2

Switching the arrangement of the winding adjacent to the pole lap (design not using alternating poles)

-transforming the original type of connection into a triangular structure following the same number of whole circuits. (there are star structure options for this technology, but field testing shows that it does not improve either efficiency or dissipation).

-calculating the additional winding capacitance value as follows:

wherein:

c is the capacitor value (in microfarads) for each phase;

p is the theoretical rated horsepower of the motor;

1.5 is a multiplier derived from practical experience; and

and 460 is a constant base voltage.

This formula does not allow for accurate calculation of the optimum capacitance value because it does not take into account the actual field of operation at the motor load parameters. This type of machine operates at a better power factor and therefore saves a certain amount of energy. However, it is of poor quality and has a relatively short working life.

Figures 8A, 8B, 8C and 8D illustrate a single phase motor in accordance with the teachings of the present invention.

In fig. 8A, the main winding is represented in two parts, shown as 62a and 62b, respectively, separated by a midpoint 0. The center point of the main winding serves the purpose of dual voltage, which allows selection of series or parallel connection options if voltage variation or output horsepower variation requires, as in any conventional motor.

Similarly, the additional winding also includes two portions, shown as 64a and 64b, in series with capacitor 66. The start winding is shown at 68, the start capacitor is shown at 70, and the centrifugal switch or isolation relay is shown at 72. Notably, the additional windings 64a, 64b are connected in anti-parallel to their respective main windings 62a, 62 b.

In fig. 8B, the main winding is represented in two parts, shown as 62a and 62B, respectively, electrically connected in parallel with each other. For other aspects, the circuit in FIG. 8B is the same as the circuit of FIG. 8A.

In fig. 8C, the additional windings 64a, 64b are electrically connected in parallel with each other, in series with the capacitor 66. For other aspects, the circuit in fig. 8C is the same as the circuit of fig. 8B.

In fig. 8D, the additional windings 64a, 64b are electrically connected in parallel with each other, in series with the capacitor 66. For other aspects, the circuit in FIG. 8D is the same as the circuit of FIG. 8A.

Figure 9 illustrates a delta wound three phase motor in accordance with the teachings of the present invention. The main windings are shown as 22, 24 and 26 and are delta connected. Additional windings are shown at 28, 30 and 32 and additional winding capacitors are shown at 34, 36 and 38. The additional windings and the respective additional winding capacitors are also electrically connected in a delta configuration. The triangular connection points of the three main windings are shown as R, S and T, respectively. The incoming line voltage connection points are shown as Ra, Sa, and Ta. Each additional winding is supplied with a different phase from its respective main winding, bringing it into a reverse field state. Each additional winding also has a predetermined capacitance value, which produces an accurate phase shift according to the method of the invention.

The additional winding 28 is connected in series with a capacitor 34, and the winding and capacitor 34 are electrically connected in parallel with the main winding 24. The additional winding 28 is connected in the opposite direction with respect to the main winding 24. Thus, current flowing through the main winding 24 is in a first direction and current flowing through the additional winding 28 flows in a second direction opposite the first direction.

The additional winding 30 is connected in series with a capacitor 36, and the additional winding 30 and the capacitor 36 are electrically connected in parallel with the main winding 26. The additional winding 30 is connected in reverse with respect to the main winding 26. Thus, current flowing through the main winding 26 is in a first direction, while current flowing through the additional winding 30 flows in a second direction opposite the first direction.

The additional winding 32 is connected in series with a capacitor 38, and the additional winding 32 and the capacitor 38 are electrically connected in parallel with the main winding 22. The additional winding 32 is connected in reverse with respect to the main winding 22. Thus, the current flowing through the main winding 22 is in a first direction, while the current flowing through the additional winding 32 flows in a second direction opposite to said first direction.

The additional windings 28, 30 and 32 have a smaller number of turns than the respective main windings 22, 24 and 26. However, even if the additional windings have as many turns as their respective main windings, an improvement in the operation of the motor can be observed. However, if the number of turns of the additional winding is greater than that of the main winding, the efficiency is substantially reduced. Furthermore, if the number of turns of the additional winding is less than half the number of turns of its associated main winding, the efficiency will be lower. It can be deduced that the number of turns in each additional winding should be between fifty and one hundred percent (50-100%) of the number of turns in its associated main winding. The actual ratio depends on the application; in addition, the number of turns can be varied by increasing and decreasing the number of legs (turns) in the additional winding, as further shown in fig. 13 and 14.

Figure 10 illustrates a star wound three phase electric machine according to the teachings of the present invention. The three main windings are shown as 22, 24 and 26 and are wound in a star configuration. Three additional windings are shown at 28, 30 and 32 and are wound in a star configuration. Additional winding capacitors are shown as 34, 36 and 38. The star connection point is shown as O and the three line voltage connections are shown as R, S and T.

As with the star configuration shown in fig. 9, each additional winding is electrically connected in series with its associated capacitor, and each additional winding and capacitor connected in series is electrically connected in parallel with its associated main winding. The additional windings are oppositely connected with respect to their associated main windings and each additional winding has a number of turns at least equal to one half the number of turns of the main winding but no more than the total number of turns of said main winding.

In particular, each additional winding is supplied with a different phase from the respective main winding. An additional winding 28, electrically connected in parallel with the main winding 24, physically nested (physically connected) with and connected in opposition to the winding 22, is connected to the line R of the main winding 24 by a capacitor 34. An additional winding 30, connected in parallel with the main winding 26, physically nested with and connected in opposition to the winding 24, is connected to the line S of the main winding 26 by a capacitor 36. An additional winding 32, connected in parallel with the main winding 22, physically nested with and connected in opposition to the winding 26, is connected to the line T of the main winding 22 by a capacitor 38. This clearly shows the reverse field state of the additional winding.

Fig. 11 shows the winding interconnections for a three-phase machine according to the invention with four poles, one delta adjacent pole, each shown in each phase A, B and C (four (4) poles for phase a, four (4) poles for phase B, and four (4) poles for phase C in the main winding Y and the additional winding V). The connection point in the line R is indicated as 80 for the main winding Y and 82a, 82b for the additional winding V. The connection point in the line S is denoted 84 for the main winding Y and 86a, 86b for the additional winding V. For line T, connection point 88 represents that of the main winding Y and connection points 90a, 90b represent that of the additional winding V. Additional winding capacitors are shown as 92, 94 and 96, respectively.

In other words, the respective delta connections of each of the main and additional windings are the three delta points 80, 84 and 88 of the main winding and the additional windings 82a, 82b, 86a, 86b and 90a, 90 b. In the main winding Y, the connections are preferably symmetrical and equidistant to each other. This novel structure corrects efficiency and energy saving problems related to the direction of rotation. This example shows the structure of one triangular circuit of a quadrupole, which corrects the rotation problem at other speeds and multiple branches in a triangular structure.

The winding shown in fig. 12 has the highest efficiency of the new winding. The main windings are shown as 22, 24 and 26 and are delta wound. Additional windings are shown as 28, 30, 32; note their reverse connection with respect to their respective main windings. The capacitors connected in series with the additional windings are shown as 34, 36 and 38 respectively. The main winding and the additional winding are both arranged in a delta configuration. The additional winding is physically nested within the delta-wound main winding. The highest efficiency is achieved since there is no direct or hard electrical connection to the supply line, i.e. the windings are supplied only by capacitors. This eliminates problems associated with currents opposite to each other and can allow maximum desaturation of the main winding.

The winding shown in fig. 13 has the second highest efficiency. The main windings 22, 24 and 26 are arranged in a delta configuration, but the additional windings 28, 30 and 32 are wired in a star configuration and physically nested within the delta configuration of the main windings. Winding capacitors 34, 36 and 38 are connected in series with the additional windings 28, 30 and 32, respectively.

Fig. 14 shows a winding having the same efficiency as the winding of fig. 13. The main windings 22, 24 and 26 are electrically connected to each other in a star configuration, but they are physically nested within each respective additional winding 28, 30 and 32. The additional windings 28, 30 and 32 are electrically connected in a delta configuration and physically nested within the star (Y) arrangement of the main windings. As in all embodiments, the winding capacitors 34, 36 and 38 are connected in series with their respective additional windings 28, 30 and 32. Furthermore, as in all embodiments, the additional windings are connected in reverse with respect to their respective main windings, and the additional windings and capacitors are connected in parallel with their respective main windings.

The embodiments illustrated in fig. 15 and 9 achieve the third best efficiency. The main windings 22, 24 and 26 and the additional windings 28, 30 and 32 are all electrically connected in a delta configuration and are physically nested, but in comparison to fig. 14 and 15, it can be seen that the additional windings 28, 30 and 32 are rotated one hundred and twenty degrees (120 °) counterclockwise in fig. 15 relative to their respective positions in fig. 14. Thus, the additional winding 30 is disposed adjacent to and in reverse connection with the main winding 22 in parallel, the additional winding 32 is disposed adjacent to and in reverse connection with the main winding 24 in parallel, and the additional winding 28 is disposed adjacent to and in reverse connection with the main winding 26 in parallel.

By changing a conventional single-phase or three-phase motor into a motor according to the teachings of the present invention, the following advantages are obtained: first, the copper density is not changed compared to conventional motors. Second, the conventional winding is split into two distinct and separate windings, following a ratio of approximately one-third (1/3) and two-thirds (2/3). Furthermore, there is no need to change the original type of winding arrangement, adjacent poles or alternating poles.

According to the invention, both windings can be wound and inserted simultaneously in only one operation in a single step.

It is possible to calculate the value (in microfarads) of the additional winding capacitor for each phase. This value is proportional to the current (in amperes) at virtually full load for each phase and inversely proportional to the square of the line voltage (in volts). The value timing is then made to be approximately 0.25 × 10⁶To 0.3X 10⁶By a multiplication factor in between. The novel interconnection of the two windings is field-oriented in opposite directions and out of phase with each other.

The novel winding improves overall efficiency under all load conditions, significantly improves power factor, and substantially reduces starting and operating currents. For example, a conventional ten horsepower motor draws approximately six (6) amps at idle, while drawing only about zero six (0.6) amps after the addition of the additional windings and capacitors disclosed herein. The same motor conventionally operates at a power factor of about 0.74 to 0.84 at full load conditions, and from twenty-five percent (25%) mechanical load to full mechanical load and above at a power factor of 0.99 when wound in accordance with the present invention.

In a single phase motor, first and second primary windings are connected at respective first ends to a primary common point and at respective second ends to first and second potential lines of line voltage. The first and second additional windings are each electrically connected in series with the winding capacitor and in parallel with the first and second potential lines and in reverse with the first and second main windings. Each of the first and second additional windings generates an electromagnetic field in a direction opposite to the electromagnetic field generated by its associated first and second main windings.

The first and second main windings have a first wire diameter and each of the first and second additional windings have a second wire diameter. The first wire diameter is about twice the second wire diameter.

A multi-phase electric machine includes a plurality of primary windings connected in a delta configuration at three connection points having line voltages. Each main winding has a first wire diameter. An additional winding and a winding capacitor are connected in parallel with each main winding. The additional winding has a second wire diameter smaller than the first wire diameter. The reverse connection of the additional winding with respect to its associated main winding generates an electromagnetic field in the opposite direction to the electromagnetic field of its associated main winding.

The present invention is a pioneering invention because it substantially improves the efficiency of an ac motor or synchronous generator over a full range of load conditions. In many cases, it enables the motor to operate at power factors in excess of 0.90 even under no-load and low-load conditions. Such performance saves half the energy required to operate the motor. About sixty-four percent (64%) of the electrical energy in the united states is consumed by AC motors, and the savings produced by the present invention are substantial. In view of the inventive statute, the appended claims should be construed legally and broadly to protect the spirit or essential characteristics of the present invention from infringement.

French patent application 0207820000, now french patent No. fr2841404, filed on 25/6/2002, is hereby incorporated by reference.

It will thus be seen that the objects set forth above, and those made apparent from the preceding description, are efficiently attained. As certain changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

The above is a description of the present invention.

The claims (modification according to treaty clause 19)

1. A single phase motor winding comprising:

a main winding having a predetermined number of turns;

an additional desaturated winding having a number of turns at least equal to about one half of said predetermined number of turns of said main winding but no more than said predetermined number of turns of said main winding;

a capacitor electrically connected in series with the additional desaturation winding;

said capacitor and said additional desaturation winding electrically connected in parallel with said main winding; and

the additional desaturation winding is connected in reverse relative to the main winding such that current flows through the main winding in a first direction and through the additional desaturation winding in a second direction, the second direction being opposite the first direction.

2. The single-phase motor of claim 1, further comprising:

said main winding formed by a conductor having a first predetermined cross section, and said additional desaturated winding formed by a conductor having a second cross section;

the first and second predetermined cross-sections are related to each other in a ratio;

the ratio is about two-thirds (2/3) to one-third (1/3).

3. A single phase electric motor comprising:

a main winding having two halves electrically connected in series with each other;

an additional desaturation winding having two halves connected in series with each other;

a capacitor connected in series with the two halves;

the additional desaturation winding and the capacitor are connected in parallel with the main winding;

each half of the additional desaturated winding is connected in reverse relative to the associated half of the main winding such that current flowing through the half of the additional desaturated winding flows in an opposite direction relative to current flowing through the half of the main winding;

each half of the additional desaturated winding has a number of turns at least equal to about half the predetermined number of turns of each half of the main winding but no more than the predetermined number of turns of each half of the main winding.

4. The single-phase motor of claim 3, further comprising:

a start winding, a start capacitor and a switching device connected in series with each other and in parallel with the main and additional desaturation windings.

5. A single phase electric motor comprising:

a main winding having two halves electrically connected in parallel with each other;

a capacitor connected in series with the two additional desaturated winding halves;

the additional desaturated winding half and the capacitor are connected in parallel with the main winding;

6. A single phase electric motor comprising:

an additional desaturation winding having two halves connected in parallel with each other;

7. A single phase electric motor comprising:

8. A delta wound three phase electric machine comprising:

first, second and third main windings connected to each other in a delta structure;

first, second and third additional desaturated windings connected to each other in a delta configuration;

the first, second and third main and additional desaturated windings are physically nested one above the other;

the first, second and third additional desaturation windings are connected in parallel and in reverse with the first, second and third main windings, respectively, such that current flowing through the first, second and third main windings flows in a first direction and current flowing through the first, second and third additional desaturation windings flows in a second direction opposite to the first direction;

first, second, and third capacitors connected in series with the first, second, and third additional desaturated windings, respectively, such that each additional desaturated winding is supplied with current in a different phase than the current supplied in the first, second, and third main windings; and

the first, second and third additional desaturated windings have a predetermined number of turns between fifty to one hundred percent (50% -100%) of the number of turns of the main winding associated therewith.

9. A star wound three phase electric machine comprising:

first, second and third main windings connected to each other in a star configuration;

first, second and third additional desaturated windings connected to each other in a star configuration;

first, second and third capacitors connected in series with the first, second and third additional desaturated windings, respectively, such that each additional desaturated winding is supplied with current in a different phase than the current supplied in the first, second and third main windings; and

10. A delta wound three phase electric machine comprising:

first, second and third main windings electrically connected to each other in a delta configuration;

first, second and third additional desaturated windings electrically and mechanically connected to each other in a delta configuration;

the first, second and third additional desaturated windings are nested within a delta configuration of the first, second and third main windings;

first, second and third capacitors connected in series with the first, second and third additional desaturation windings, respectively; and

11. A delta wound three phase electric machine comprising:

first, second and third main windings electrically and mechanically connected to each other in a delta configuration;

first, second and third additional desaturated windings electrically connected to each other in a star configuration;

12. A star wound three phase electric machine comprising:

first, second and third main windings electrically connected to each other in a star configuration;

first, second and third additional desaturated windings electrically connected to each other in a delta configuration;

13. A delta wound three phase electric machine comprising:

the first, second and third additional desaturation windings are connected in parallel and in reverse with the second, third and first main windings, respectively, such that current flowing through the first, second and third main windings flows in a first direction and current flowing through the second, third and first additional desaturation windings flows in a second direction opposite to the first direction;

first, second and third capacitors connected in series with the first, second and third additional desaturated windings, respectively, such that each additional desaturated winding is supplied with current in a different phase than the current supplied in the first, second and third main windings, thereby obtaining a one hundred twenty degree (120 °) phase shift; and

Claims

1. A method for increasing the efficiency of an ac machine, comprising the steps of:

selecting a first wire diameter for a first conductor and a second wire diameter for a second conductor such that the first wire diameter is greater than the second wire diameter;

winding a first conductor to form a main winding;

winding a second conductor to form an additional winding;

electrically connecting a capacitor in series with the additional winding;

electrically connecting the additional winding and a capacitor in parallel with the first winding; and

electrically connecting the additional winding in a reverse direction relative to the main winding such that current in the first winding flows in a first direction and current in the additional winding flows in a second direction opposite the first direction.

2. The method of claim 1, further comprising the steps of:

forming the main and additional windings and a capacitor for each phase of the motor.

3. The method of claim 2, further comprising the steps of:

forming three of said main windings;

forming three of said additional windings and capacitors; and

the three main windings are electrically connected with three additional windings and capacitors in a delta configuration.

4. The method of claim 2, further comprising the steps of:

forming three of said main windings;

forming three of said additional windings and capacitors; and

the three main windings are electrically connected with three additional windings and capacitors in a star configuration.

5. The method of claim 1, further comprising the steps of:

determining the current drawn by the ac motor at full load;

determining a line voltage supplied to the AC motor; and

the capacitance of the capacitor is determined by multiplying the current drawn by the ac motor at full load by an empirical factor to obtain a result, and dividing the result by the square of the line voltage.

6. The method of claim 5, further comprising the steps of:

at about 0.25X 10⁶To about 0.30X 10⁶To said empirical coefficients.

7. The method of claim 1, further comprising the steps of:

the first wire diameter and the second wire diameter are selected such that the cross-sectional area of the first wire diameter is greater than the cross-sectional area of the second wire diameter by a ratio of approximately two-thirds 2/3 to one-third 1/3.

8. The method of claim 1, further comprising the steps of:

selecting a first length of the first conductor; and

a second length of the second conductor is selected that is approximately half the length of the first conductor.

9. The method of claim 1, further comprising the steps of:

selecting a first length of the first conductor; and

selecting a second length of the second conductor having a length in a range from about half the length of the first conductor to a length equal to the length of the first conductor.

10. The method of claim 1, further comprising the steps of:

simultaneously performing said step of winding a first conductor to form a main winding and said step of winding a second conductor to form an additional winding for at least a portion of time during said step of winding said first conductor.

11. A single phase motor winding comprising:

a main winding having a predetermined number of turns;

an additional winding having a number of turns at least equal to about half of the predetermined number of turns of the main winding but no more than the predetermined number of turns of the main winding;

a capacitor electrically connected in series with the additional winding;

the capacitor and the additional winding are electrically connected in parallel with the main winding; and

the additional winding is connected in reverse with respect to the main winding such that current flows through the main winding in a first direction and through the additional winding in a second direction, the second direction being opposite the first direction.

12. The single-phase motor of claim 11, further comprising:

said main winding formed by a conductor having a first predetermined cross-section, and said additional winding formed by a conductor having a second predetermined cross-section;

the first and second predetermined cross-sections are proportional to each other;

the ratio is about two-thirds (2/3) to one-third (1/3).

13. A single phase electric motor comprising:

an additional winding having two halves connected in series with each other;

a capacitor connected in series with the two halves;

the additional winding and the capacitor are connected in parallel with the main winding;

each half of the additional winding is connected in reverse with respect to an associated half of the main winding such that current flowing through the half of the additional winding flows in an opposite direction with respect to current flowing through the half of the main winding.

14. The single-phase motor of claim 13, further comprising:

each half of the additional winding has a number of turns at least equal to about half of the predetermined number of turns of each half of the main winding, but not more than the predetermined number of turns of each half of the main winding.

15. The single-phase motor of claim 14, further comprising:

a start winding, a start capacitor and a switching device connected in series with each other and in parallel with the main and additional windings.

16. A single phase electric motor comprising:

an additional winding having two halves connected in series with each other;

a capacitor connected in series with the two additional winding halves;

the additional winding half and the capacitor are connected in parallel with the main winding;

each half of the additional winding is connected in reverse relative to an associated half of the main winding such that current flowing through the half of the additional winding flows in an opposite direction relative to current flowing through the half of the main winding;

17. A single phase electric motor comprising:

an additional winding having two halves connected in parallel with each other;

a capacitor connected in series with said two additional winding halves;

18. A single phase electric motor comprising:

an additional winding having two halves connected in parallel with each other;

a capacitor connected in series with said two additional winding halves;

19. A delta wound three phase electric machine comprising:

first, second, and third main windings connected to each other in a delta structure;

first, second, and third additional windings connected to each other in a delta configuration;

the first, second, and third main and additional windings are physically nested one above the other;

the first, second, and third additional windings are connected in parallel and in reverse with the first, second, and third main windings, respectively, such that current flowing through the first, second, and third main windings flows in a first direction and current flowing through the first, second, and third additional windings flows in a second direction opposite to the first direction;

first, second, and third capacitors connected in series with the first, second, and third additional windings, respectively, such that each of the additional windings is supplied with current in a different phase from the current supplied to the first, second, and third main windings;

the first, second, and third additional windings have a predetermined number of turns that is between fifty percent to one hundred percent (50% -100%) of the number of turns of the main winding associated therewith.

20. A star wound three phase electric machine comprising:

first, second, and third main windings connected to each other in a star configuration;

first, second, and third additional windings connected to each other in a star configuration;

21. A delta wound three phase electric machine comprising:

first, second, and third main windings electrically connected to each other in a delta configuration;

first, second, and third additional windings electrically and mechanically connected to each other in a delta configuration;

the first, second, and third additional windings are nested within the triangular structure of the first, second, and third main windings;

first, second, and third capacitors connected in series with the first, second, and third additional windings, respectively; and

22. A delta wound three phase electric machine comprising:

first, second, and third main windings electrically and mechanically connected to each other in a delta configuration;

first, second, and third additional windings electrically connected to each other in a star configuration;

23. A star wound three phase electric machine comprising:

first, second and third additional windings electrically connected to each other in a delta configuration;

the first, second and third main and additional windings are physically nested one above the other;

the first, second and third additional windings are connected in parallel and in reverse with the first, second and third main windings, respectively, such that current flowing through the first, second and third main windings flows in a first direction and current flowing through the first, second and third additional windings flows in a second direction opposite to the first direction;

the first, second and third additional windings have a predetermined number of turns that is between fifty percent and one hundred percent (50% -100%) of the number of turns of the main winding associated therewith.

24. A delta wound three phase electric machine comprising:

first, second, and third capacitors connected in series with the first, second, and third additional windings, respectively, such that each of the additional windings is supplied with current in a different phase than the current supplied in the first, second, and third main windings, thereby obtaining a one hundred twenty degree (120 °) phase shift; and