RU2441306C1 - Power device with double synchronisation - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: power device may have the first generator plant with the first motor connected with a drive with the first generator, and the second generator plant with the second motor connected with a drive to the second generator. Besides, the power device may have a common bus and a control unit interacting with the first and second generator plants. The control unit is designed to delay directing power from the second generator to the common bus until the first and second motors are not mechanically synchronised to a significant extent.

EFFECT: direction of power from the first generator to the common bus and synchronisation of power generation from the second generator with power generation from the first generator.

20 cl, 3 dwg

Description

The present invention relates, in General, to a power device and, in particular, to a power device having double synchronization.

Most power devices have multiple generator sets to provide power to the electricity. In order to supply electricity, often such generating sets are connected in parallel via a common bus. Following one generator set connected to a common bus, any additional generator sets connected to the bus must produce electricity that matches the voltage, frequency, and phase angle with the electricity produced by the first generator set. Such matching is also known as electrical synchronization of generator sets. Improved synchronization leads to a smoother transition and lower jump on the generator and load.

When multiple generators are located close to each other, as in the case of a conventional power plant or the onboard power plant of a large marine vessel, vibrations from different generating sets can pass through their supports and / or dampen or increase. Vibrations inside a conventional power plant or the onboard power plant of a large marine vessel can be excessive when the generator set engines have an odd number of cylinders. That is, an engine having an odd number of cylinders is mechanically unbalanced. For example, in a nine-cylinder engine, four pistons can be moving upward, while five pistons can move downward. As a result of the unbalanced masses and their movements, in this example there will be a superior resulting force in the downward direction. This force, depending on the weight and speed of such an engine, the size of the pistons and the type of support (rigid or flexible), can be very significant in order to transmit vibrations to the engine mounts and surrounding supporting structures with a sufficient amplitude at which structural damage, and / or such that vibrations become unpleasant for the owner / operator of the engine. It is also a problem when multiple engines located close to each other work synchronously with each other (i.e., when eight pistons move up and ten move down, as would be the case with two closely working nine-cylinder engines).

One device that addresses the issue of synchronizing multiple generator sets is described in US 6,552,454 (Kern et al. April 22, 2003). This document discloses a generator structure comprising first and second generator sets located inside a common housing. Each generator set contains an engine and an alternator controlled by an engine for generating electrical energy. The first generator set produces electric energy of the first magnitude and frequency, the second generator set generates electric energy of the second magnitude and frequency. The generator design also contains a control unit that controls the magnitude and phase of the electric energy generated by the first and second generator sets, and adjusts the speed of the engines using an electronic control device such that the electricity generated by the first and second generators is brought together in concert, no there is no phase difference between the attached sinusoidal oscillations, and thus, the sinusoidal oscillations are of the same frequency. In addition, the control device adjusts the output voltages of the generator sets so that the output voltages are generally equal. As soon as the frequencies of the output voltages are synchronized, the control device closes the switches in order to connect the electricity from the first and second generator sets to the load.

Although the generator design described in US 6552454 allows phase, frequency and voltage matching, it does not take into account the vibrations caused by unbalanced motors. And since the generating sets are closely located in a common housing, depending on when the motors are electrically synchronized, it may be possible to electrically synchronize two generators when the two respective motors are in phase with each other. And if the motors are sufficiently in phase and unbalanced, vibrations can be quite capable of damaging the overall casing.

The power device according to the present invention solves the above problems.

One aspect of the present invention relates to a power device. The power device may include a first generator set with a first engine connected to the drive with the first generator, and a second generator set with a second engine connected to the drive with the second generator. The power device may also comprise a common bus and a control unit in cooperation with the first and second generator sets. The control unit can be configured to direct electricity from the first generator to the common bus and synchronize the generation of electricity from the second generator with the generation of electricity from the first generator. The control unit, in addition, can be configured to delay the direction of electric power from the second generator to the common bus until the first and second engines are mechanically synchronized to a large extent.

Another aspect of the present invention relates to a method of supplying electricity. According to the method, a first electric power source is activated to generate electric power, and electric power is directed from the first electric power source to a common bus. In addition, you can activate the second source of electricity to generate electrical energy and synchronize the generation of electricity from the second source of electricity with the generation of electricity from the first source of electricity. The method may further comprise delaying the direction of electric power from the second electric power source to the common bus until the first and second electric power sources are mechanically synchronized to a significant degree.

The present invention is illustrated by drawings, which represent the following:

figure 1 - a visual illustration of a power plant;

figure 2 is a power device that can be used in the power plant of figure 1, in section;

figure 3 is a block diagram showing an example of the operation of the corresponding power device of figure 2.

Figure 1 shows a power plant 10 comprising a power device 12 for supplying electricity to a power load 14. Power plant 10, although shown in figure 1 on a large marine vessel, can also operate on land. The power plant 10 may include an anchor platform 16, such as a support frame connected to the housing of the power plant 10, and on which the power device 12 can be installed. It should be noted that the power device 12 can be installed on the anchor platform 16 rigidly or movably.

In the embodiment shown in FIG. 1, the power load may comprise any device or devices that require uninterrupted electricity to perform one or more tasks, including, but not limited to, electric lighting and drive motors corresponding to the illustrated marine vessel. In some embodiments, power load 14 may require electrical energy in a particular form, such as a three-phase alternating current.

As shown in FIG. 2, the power device 12 may include at least two closely spaced sources of electricity 18, acting to generate electricity, and a power network, such as a common bus 19, for transmitting electricity from the sources 18 of the electricity to the power load 14 (see figure 1). In one embodiment, each power source 18 may comprise a motor 20 coupled to a drive with a generator 22 to form a generator set. Although the generating sets are shown end-to-end, alternatively they can be located in parallel or in random order inside a common aggregate.

Each engine 20 may be any type of heat engine for generating mechanical energy by burning fuel, including, but not limited to, a diesel engine, a heavy fuel engine, a gasoline engine, and a gas engine. In the illustrated embodiment, each engine 20 may be unbalanced. That is, each engine 20 may have an odd number of cylinders 24, which is manifested in the free mass or in the moment of free mass. In a particular embodiment, engine 20 may comprise nine cylinders 24. With respect to nine cylinders, four pistons 26 may be coupled to a common crankshaft 28 and move upward, while five pistons 26 also coupled to a crankshaft 28 will move downward. Thus, due to unbalanced masses and their moments, a superior resultant force arises in the downward direction. This superior force is known as free mass. If not taken into account, the free mass can cause significant vibrations in the anchor platform 16. And when many engines 20 are closely located and act in phase with each other (i.e., the crankshafts 28 of each engine 20 are oriented at approximately the same angle and rotate approximately at the same speed), the magnitude of the amplitude of the vibrations may be excessive.

A sensor 30 may be coupled to each engine 20 to determine the instantaneous position of each crankshaft 28. In this embodiment, the sensor 30 may comprise, for example, a pulse transmitter configured to generate a pulse each time the crankshaft 28 intersects a certain angle. For example, when the crankshaft 28 of one engine 20 rotates most of the pistons 26 to traverse the top dead center position (TDC), the corresponding pulse transmitter may generate a first electronic pulse. Similarly, when the crankshaft 28 of the second engine 20 rotates most of the pistons 26 to traverse the bottom dead center position (BDC), the corresponding pulse transmitter can generate a second electronic pulse. When the first and second electronic pulses are generated at about the same time, the motors can be phase shifted by approximately 180 ° and the resulting vibrations can be largely damped or even completely damped by each other. In contrast, the longer time between the first and second pulses may correspond to motors 20, which to a large degree are in phase with each other and the resulting vibrations can be added. The sensor 30 can alternatively be connected with generators 22, for example, with rotors that are directly controlled by motors 20, and / or with the windings of the generators 22.

Each generator 22 may be any type of electric power generating device mechanically coupled to the engine 20 to generate energy and convert at least a portion of this mechanical energy into electrical energy. For example, each generator 22 may comprise an AC asynchronous generator, a permanent magnet generator, an AC synchronous generator, or a switchable reactive generator. In one embodiment, each generator 22 may contain seven pairs of single wires twisted in pairs (not shown) located along the stator perimeter (not shown) to create an alternating current with a frequency of 60 Hz, with each twisted pair being three-phase.

The power device 12 may also comprise a synchronization and load distribution control unit 32 for controlling the operation of the power device 12. The control unit 32 may comprise commonly known elements that cooperate to synchronize the electrical output of a plurality of electric power sources 18 and connect the output to a common electric power unit directed to the load 14 (see figure 1). For example, the control unit 32 may include, among other accessories, one or more breakers (not shown) installed between each generator 22 and a common bus 19, and / or between a common bus 19 and a power load 14 for selectively connecting an electrical output of one or more generators 22 with a common bus 19, and / or in order to selectively connect a common bus 19 with a power load. In addition, the control unit 32 may be in cooperation with each engine 20, each generator 22, and sensors 30 to monitor and / or control one or more aspects of the operation of the generator set. The control unit 32 may also contain one or more control devices (not shown) for obtaining the input relative characteristics of the electrical phenomena generated by each electric power source 18, such as current, frequency, phase and / or voltage. In addition, the control unit 32 may receive information regarding the amount of electricity required by the power load 14. For example, the control unit 32 may receive information such as voltage and / or current over one or more portions of a common bus 19 and voltage and / or current one at a time or more power load elements 14.

By closing the first breaker associated with the first of the generators, it is possible to electrically connect the output of this generator 22 to a common bus 19. To electrically connect one additional generator 22 to a common bus, it may be necessary that the output of the additional generator 22 has a voltage, frequency and phase angle, in largely matched to the voltage, frequency, and phase angle of the first generator 22. Improved matching can result in a smoother transition and lower jump on power load 14. Control unit 32 can adjust the operation of an additional source of electricity 18 (i.e., engine 20 and / or generator 22) to vary the electrical output characteristics of the generated electricity and match the electrical output characteristics of the first generator 22. As soon as all synchronization conditions (i.e. frequency, phase angle and voltage) are satisfied, the command to close the chopper can be given by the control unit 32 to the chopper connected to the second generator 22 and after a short delay in starting, the chopper can be closed bitch.

The control unit 32, in addition to synchronizing the power generation of multiple generators 22, can also control the mechanical synchronization of the engines 20 by controlling the same generators 22. In particular, after the electrical synchronization and before the control unit 32 gives a command to close the breaker in an attempt to return additional generators 22 to the network , the control unit 32 can, by a first check with the aid of the sensor 30, recognize whether the coupled first and additional motors 20 are in phase (i.e., whether a large part moves to TDC the pistons 26 of the first engine 20 at about the same time as most of the pistons 26 of the second engine 20). If the motors 20 operate to a large extent out of phase, the control unit 32 may act and instruct the circuit breaker to close. However, if the motors 20 are not operating sufficiently out of phase, the control unit 32 may delay the return of additional generators 22 to the network and abort the current synchronization attempt. The control unit 32 may initiate another synchronization attempt and repeat the same synchronization cycle several times. In one embodiment, the control unit 32 may attempt to double synchronize (electrical and mechanical) up to ten times before initiating a backup strategy. During the backup strategy, the control unit 32 may instruct the circuit breaker to close regardless of mechanical synchronization. Thus, the load 14 may experience only a slight delay in the supply of electricity if the mechanical synchronization is unsuccessful.

Figure 3 is a block diagram showing an example of the operation of the power device 12. Figure 3 will be discussed in the next part of an additional explanation of the described device and its operation.

The power device can be used wherever electrical and mechanical matching is desired, for example, when multiple power sources having unbalanced moving masses are closely spaced. During operation of the disclosed power device, electrical and mechanical synchronization (i.e., double synchronization) can be performed to form a common source of electrical energy and simultaneously dampen vibrations associated with electrical sources. Next will be described the operation of the power device 12.

To initiate the operation of the power device 12, each source 18 of electricity can be powered and energy from one source 18 can be directed to a common bus 19 (step 100). To start each electric power source 18 in the respective engine 20, the travel speed for controlling the generators 22 can be increased. In some situations, increasing the speed of the engine 20 may include starting the ignition. In other cases, engine 20 may already be running, but only at a standby level. As soon as the stroke speed has risen at the output of the first of the engines 20 and the generator 22 produces electricity at the level required by the load 14, the control unit 32 may issue a command to close the output breaker in order to electrically connect the output of the generator 22 to the common bus 19. Although additional generators 22 can also generate energy at the level required by the load 14, they can remain isolated from the common bus 19 until the generation of electricity from additional generators 22 is not significantly consistent with heat with power generation of the first generator 22.

The control unit 32 can coordinate the generation of electricity from additional generators 22 with the generation of electricity of the first generator 22, before additional connections to a common bus 19 can be performed (software step). The control unit 32 may adjust the performance of the additional motors 20 and / or generators 22 in order to vary and substantially match frequencies, phase angles, and voltages. Once the control unit 32 determines that the power generation of any additional generators is largely consistent with the power generation of the first generator 22 (step 120), the control unit 32 can stop mechanical synchronization between the motors 20. That is, the control unit 32 can compare the mechanical phase angle of the engine 20, associated with the first generator 22, with the mechanical phase angle of the remaining engines 20 using the sensor 30 (step 130). If the control unit 32 determines that the mechanical phase angle of the remaining engines 20 is synchronized within the range of acceptable values of the engine 20 controlling the first connected generator (step 140), the control unit 32 may command to close an additional chopper to connect the remaining generators 22 to the common bus 19 ( step 150). In a preferred embodiment, the range of acceptable values is 170-190 °.

If the control unit 32 determines that the mechanical phase angle of the remaining motors is not synchronized in the range of acceptable values, the control unit 32 can interrupt the current synchronization attempt and determine the number of attempts made so far in the process (step 160). If the number of attempts is less than the allowable number, for example ten attempts, the process can be restarted by returning control to step 110. However, if the allowable number of attempts has been made, the control unit 32, on the contrary, connects the electrical output from additional generators 22 to the common bus 19 without reckoning with mechanical synchronization (step 150). Thus, when mechanical synchronization is impossible or was unsuccessful, the delay time of the power supply associated with an excessive number of attempts can be minimized.

Specialists it is clear that various modifications and variations can be made in the described power device, without going beyond the essence and scope of the invention. Other preferred embodiments of the power device will become apparent to those skilled in the art from consideration of the details and application of the power device and methods disclosed herein. For example, although the power device 12 was originally described for only two generator sets, it should be noted that the control unit 32 can also control the electrical and mechanical synchronization of more than two generator sets. However, it should be noted that if more than two generator sets are mechanically synchronized, the non-phase angle will be different from that described above (i.e., different from 180 °), while the operation of a number of engines requires mechanical synchronization. In addition, although the primary implication for unbalanced engines (i.e., engines having an odd number of cylinders resulting in free mass) double synchronization according to the present invention can be applied just as easily to an engine having an even number of cylinders, but all at the same time subject to excessive vibrations. In the described embodiment, the engine 20 may contain nine cylinders 24. It should be noted that the examples and descriptions are considered as examples only, the true scope of the disclosure is indicated by the following claims and their equivalents.

Claims (20)

1. A power device comprising a first generator set with a first engine connected to the first generator by means of a drive, a second generator set with a second engine connected to the second generator by means of a drive, as well as a common bus and a control unit configured to interact with the first and second generator sets, while the control unit is designed to direct electric power from the first generator to the common bus, as well as to delay the direction of the common electric bus about t of the second generator until the first and second engines are mechanically synchronized to a large extent. 2. The power device according to claim 1, in which the control unit is designed to synchronize the generation of electricity from the second generator with the generation of electricity from the first generator. 3. The power device according to claim 2, in which the generation of electricity from the second generator is synchronized with the generation of electricity from the first generator when at least the phase angle, frequency and voltage of the generation of electricity from the first and second generators are largely consistent. 4. The power device according to claim 2, containing a first sensor installed to create a first signal indicating the angle of rotation of the first engine; and a second sensor installed to create a second signal indicating the angle of rotation of the second engine, the control unit being used to compare the first and second signals after synchronizing the generation of electricity of the second generator with the generation of electricity of the first generator. 5. The power device according to claim 4, in which the control unit is designed to direct electricity from the second generator to the common bus only when the phase mismatch of the rotation angles of the first and second engines is in the range from 170 to 190 °. 6. The power device according to claim 5, in which the control unit is designed to direct electricity from the second generator to the common bus only when the phase mismatch of the rotation angles of the first and second engines is mainly 180 °. 7. The power device according to claim 2, in which the control unit is designed for many attempts of mechanical synchronization and directing electricity from the second generator to the common bus after synchronizing power generation without taking into account mechanical synchronization, when many attempts are made. 8. The power device according to claim 7, in which the number of attempts is ten. 9. The power device according to claim 1, in which at least one of the first and second engines has an unbalanced variable mass. 10. The power device according to claim 9, in which the unbalanced variable mass is due to at least one of the first and second engines having an odd number of cylinders. 11. The power device of claim 10, in which the first and second engines are substantially identical and contain nine cylinders each. 12. The power device according to claim 1, in which the first and second engines are installed on a common anchor platform. 13. The method of supplying electricity, in which initiate the first source of electricity to generate electrical energy; directing electricity from the first source of electricity to a common bus; initiate a second source of electricity to generate electrical energy; and delaying the direction of the electric power from the second electric power source to the common bus until the first and second electric power sources are mechanically synchronized to a large extent. 14. The method according to item 13, in which synchronize the generation of electricity from the second source of electricity with the generation of electricity from the first source of electricity. 15. The method according to 14, in which the generation of electricity from the second source of electricity is synchronized with the generation of electricity from the first source of electricity, when the phase angle, frequency and voltage of the generation of electricity from the first and second sources of electricity are largely consistent. 16. The method according to 14, in which the first rotation angle of the first electric power source is determined, the second rotation angle of the second electric power source is determined, and the first and second rotation angle is compared after synchronizing the electric power generation of the second electric power source with the electric power generation of the first electric power source. 17. The method according to clause 16, in which direct electricity from the second source of electricity to the common bus only when the phase difference in rotation angles of the first and second source of electricity is mainly 180 °. 18. The method according to 14, in which there are many attempts at mechanical synchronization; and directing the electric power from the second electric power source to the common bus after synchronization of electric power generation without taking into account mechanical synchronization when many attempts have been made. 19. The method according to clause 16, in which the number of attempts is ten. 20. A power plant comprising a common anchor platform, a first generator set mounted on a common anchor platform and having a first mass unbalanced engine connected to the first generator by means of a drive, a second generator set mounted on a common anchor platform near the first generator set and having a second unbalanced by weight, an engine connected to the second generator by means of a drive, a common bus, designed to transfer electrical energy from the first and watts A set of generating sets for a power load, as well as a control unit in cooperation with the first and second generator sets, the control unit is designed to direct electricity from the first generator to the common bus, as well as synchronize the generation of electricity from the second generator with the generation of electricity from the first generator and delaying the direction of electricity from the second generator supplied to the common bus until the first and second mass-unbalanced engines are mechanically nhroniziruyutsya largely vibration and sent to the first generator set common anchor platform is at least partially not extinguish the vibrations from the second generator set.

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