Load predictor system for a generator system

Abstract

Systems and methods include an AC motor (44) and one or more gas turbine generators (48) configured to provide power to the AC motor. The system also includes a controller (38) configured to control operation of the one or more gas turbine generators by determining that the power is to be used to start the AC motor. Upon determining that the power is to be used to start the AC motor, the controller is configured to boost the power prior to starting the AC motor. The controller uses the boosted power to pre-compensate for a decrease in an electrical parameter of the power due to an increased demand for starting of the AC motor.

Description

Background Technology

[0001] The subject matter disclosed in this article relates to using gas turbine engines to power loads. Specifically, gas turbine engines are used to generate energy that can be converted into electrical energy.

[0002] Typically, a gas turbine engine burns a mixture of compressed air and fuel to produce combustion gases. These combustion gases can flow through one or more turbine stages to generate electricity for loads and / or compressors. Gas turbines can be used to power generators, which supply electrical energy to loads and / or electric motors. However, certain load conditions (e.g., bump starts) can create significant (e.g., 30MW-80MW) and almost instantaneous (e.g., 0.5s-1.5s) demands on gas turbine generator systems, potentially causing them to fail to provide sufficient power at rated operating parameters due to voltage and / or voltage drops (power outages). Summary of the Invention

[0003] The following outlines certain embodiments equivalent to the scope of the originally claimed invention. These embodiments are not intended to limit the scope of the claimed invention, but rather are intended only to provide a brief overview of the possible forms of the invention. In practice, the invention can include various forms that may be similar to or different from the embodiments set forth below. In a first embodiment, a system includes an AC motor and one or more gas turbine generators configured to supply power to the AC motor. The system also includes a controller configured to control the operation of the one or more gas turbine generators by determining that the power should be used to start the AC motor. After determining that the power should be used to start the AC motor, the controller is configured to boost the power before starting the AC motor. The controller uses the boosted power to pre-compensate for the decrease in the electrical parameters of the power due to the increased demand for starting the AC motor.

[0004] In a second embodiment, a system includes a high-power load and a turbine generator configured to supply power to the high-power load. The system also includes a controller that, upon determining that the high-power load has a sharp, planned increase in demand, enhances one or more aspects of the power supply to pre-compensate for any decrease in those aspects due to the sharp increase in planned demand. The controller can also determine a reduction in the power demand of the high-power load and can implement a reduction in one or more aspects of the power supply.

[0005] In a third embodiment, a tangible, non-transitory, computer-readable medium stores instructions that, when executed by a processor, cause the processor to manage the operation of a gas turbine system to generate electricity. The processor executing the instructions can also determine whether to start the electric motor according to a planned start-up. Furthermore, the processor can increase at least one parameter of the generated electricity before starting the motor, and start the motor using the increased parameter of the generated electricity to pre-compensate for any decrease in the parameter of the generated electricity. Attached Figure Description

[0006] These and other features, aspects, and advantages of the invention will be better understood when the following detailed description is read with reference to the accompanying drawings, in which the same reference numerals denote the same parts throughout the drawings, wherein:

[0007] Figure 1 This is a block diagram of a gas turbine engine configured to provide load power according to an embodiment of the present disclosure;

[0008] Figure 2 This is a block diagram of a gas turbine engine configured to power one or more electric motors and loads, according to an embodiment of this disclosure.

[0009] Figure 3 This is a perspective view of two gas turbine engines configured to power one or more loads according to an embodiment of this disclosure;

[0010] Figure 4 It is a graph of generator frequency versus generator power output according to one embodiment of this disclosure;

[0011] Figure 5 This is a flowchart illustrating the prediction of increased power demand when operating a gas turbine generator to pre-compensate for increased power demand, according to one embodiment of this disclosure; and

[0012] Figure 6 A graph showing various electrical parameters of circuit elements before, during, and after powering a load using a gas turbine generator with pre-compensation for the power load demand of the gas turbine generator, is presented according to one embodiment of the present disclosure. Detailed Implementation

[0013] One or more specific embodiments of this disclosure will now be described. To provide a concise description of these embodiments, not all features of the actual implementation may be described in the specification. It should be understood that, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developer's objectives; specific objectives, such as compliance with system-related and business-related constraints, may vary in different implementations. Furthermore, it should be understood that such development work can be complex and time-consuming, but remains a routine task of design, fabrication, and manufacturing for those skilled in the art who benefit from this disclosure.

[0014] When describing elements of various embodiments of the invention, the articles “a,” “an,” “the,” and “the” are intended to refer to one or more elements present in the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that additional elements may be present in addition to the listed elements. Furthermore, the term “or” is intended to be inclusive, meaning that A or B includes A alone, B alone, or both A and B.

[0015] This disclosure generally relates to starting an AC motor using a generator powered by a gas turbine generator. When starting a high-power (e.g., 30 kilohp (kHp)) AC motor (or other high-demand transient load), the gas turbine generator may experience demand spikes, causing output parameters (e.g., frequency or voltage) to drop. In these high-demand loads, gradually increasing demand over time may be impossible or impractical due to the cost or increased complexity of systems containing such loads. Instead of gradually increasing demand, the system may pre-compensate for this drop. During pre-compensation, the generator may provide a power boost before starting the high-power AC motor. This power boost also increases one or more parameters of generator operation that are affected by the drop in output parameters. By providing a power boost to the generator before starting the AC motor, the generator is able to prepare for the increase in power demand and can respond to the increase in power demand in a stable manner, allowing the generator to quickly restore its steady-state, balanced operation (e.g., rated operating frequency and voltage) when supplying power to the AC motor or other loads attached to it.

[0016] According to this implementation scheme, these and other processes can be performed or facilitated by a generator powered by a gas turbine system. Figure 1A block diagram of an embodiment of the gas turbine system 10 is shown. For example, the gas turbine system 10 may be part of a combined cycle system or combined with other gas turbine system motors 10 to power one or more loads 12. Specifically, the gas turbine system 10 is typically configured to drive the load 12 by burning a mixture of compressed air and fuel 15 (e.g., natural gas, light or heavy distillate, naphtha, crude oil, residual oil, or syngas). Combustion takes place within a combustor 16, which may include one or more combustion chambers. Air 14 enters at the inlet of the compressor 20, is filtered, and is subsequently compressed within the compressor 20 via one or more compression stages.

[0017] To initiate the combustion process within burner 16, air 14 is injected into compressor 20 via compressed air stream 18. Compressed air stream 18 is mixed with fuel 15. Using the mixture of fuel 15 and air 14, ignition can occur. Ignition produces hot combustion gas 26 that powers gas turbine system 10. More specifically, hot combustion gas 26 flows through turbine 28 having one or more compression stages, which drives load 12 via shaft 30. For example, combustion gas 26 can apply prime movers (e.g., via convection, expansion, etc.) to turbine rotor blades within turbine 28 to rotate shaft 30. In an exemplary process, hot combustion gas 26 can force turbine blades in turbine 28 to rotate shaft 30 along the axis of gas turbine system 10. As shown, drive shaft 30 can be connected to various components of turbine system 10, including compressor 20 or load 12.

[0018] As previously described, drive shaft 30 can connect turbine 28 to compressor 20 to form a rotor. Compressor 20 may also include compressor blades coupled to drive shaft 30. Thus, rotation of the turbine blades in turbine 28 causes drive shaft 30, which connects turbine 28 to compressor 20, to rotate the compressor blades within compressor 20. This rotation of the compressor blades in compressor 20 causes compressor 20 to compress air 14 to produce compressed air flow 18. As previously described, compressed air flow 18 is then fed to combustor 16 and mixed with other combustion components. Shaft 30 can drive compressor 20 in addition to or in place of load 12. As an example, load 12 may be a generator, propeller, transmission, or drive system, etc.

[0019] Once the turbine 28 extracts work from the hot combustion gases 26, the exhaust gas stream 32 can be supplied to the exhaust section 34, where it can be cooled or further treated. For example, the exhaust section 34 may include a catalyst section 36, which includes a carbon monoxide (CO) catalyst, NO catalyst, etc. xThe catalyst, unburned hydrocarbon catalyst, or any similar metal-based catalyst (e.g., platinum-based catalyst). For example, in the illustrated embodiment, catalyst section 36 may include a NOx catalyst or a CO catalyst. x The catalyst is configured to disrupt the NO in the exhaust gas stream 32 x Gas. Then, the exhaust gas flow 32 can leave the emission section 34.

[0020] As shown, the gas turbine system 10 includes a controller 38. The controller 38 may include one or more processors 66 and a memory 68, which may collectively support operating systems, software applications, and systems that can be used to implement the techniques described herein. Specifically, the controller 38 may include code or instructions stored in a non-transitory machine-readable medium (e.g., memory 68) and executed, for example, by one or more processors 66 that may be included in the controller 38. The processor 66 may receive operating parameters from various components of the gas turbine system 10, including shaft rotation speed, the frequency of electricity generated by the gas turbine system in the generator driven by shaft 30, the voltage of the electricity, demand from one or more loads 12, or other suitable parameters. In some embodiments, some parameters are measured directly, while others are determined indirectly based on other measurements. For example, in some embodiments, the controller 38 may derive various parameters, such as the operating speed of shaft 30 or the connected generator, using an algorithmic model or lookup table (e.g., stored in memory) with electrical parameters such as the frequency or voltage of the electricity generated by the generator. Furthermore, the controller 38 may monitor the operation of various parts of the gas turbine system 10. The monitored parameters can be used to control (e.g., adjust) one or more aspects of the operating parameters of the gas turbine system 10.

[0021] As shown, the controller 38 may include a predictor circuit 39 for predicting a significant increase in demand. The predictor circuit 39 causes the controller 38 to pre-enhance the output of the gas turbine system 10 and the connected generator. As previously described, this pre-enhancement pre-compensates for the reduction in electrical parameters of the generator in response to increased demand. The predictor circuit 39 may include physical circuitry or may be implemented at least partially using instructions stored in memory 68 and running on the processor 66 of the controller 38.

[0022] Figure 2This is a schematic diagram 40 of a gas turbine 28 driving a generator 42 that supplies power to a load 12 or an electric motor 44. The electric motor 44 may include an electric motor powered by the current generated in the generator 42. Each gas turbine 28 and generator 42 may together form a gas turbine generator 48. A shaft 30, rotating due to the torque generated by the gas turbine 28, may be connected to the corresponding generator 42. The rotation of the gas turbine 28 can power the corresponding generator 42. More specifically, the gas turbine 28 is connected to a rod in the generator 42 (e.g., coupled to the shaft 30), which can be used to generate electricity via a magnetic induction mechanism in the generator 42. The generator generates electrical energy by converting rotational energy received from the shaft 30 into electrical energy. In other words, the generator uses magnetic induction to convert rotational energy into electrical energy. Due to the principle of magnetic induction, an electric charge can be induced by moving a conductor in a magnetic field. The generator 42 utilizes this principle by rotating the shaft 30 in a magnetic field or by moving one or more magnets in the magnetic field within the generator 42. This movement can generate electricity, which can be used to supply power to the load 12 or the electric motor 44 attached to the generator 42. Furthermore, generator 42 can be electrically connected to one or more motors 44 or load 12. Through this electrical connection, generator 42 can provide electrical energy to operate motor 44. As can be understood, the AC power generated by generator 42 can have a frequency determined by the rotation of a magnet, the rod of generator 42 which can rotate the magnet. This rotation provides torque to rotate the magnet, which is displaced in the magnetic field, at a rate that provides the AC power frequency. As will be discussed below, when load demand increases rapidly (e.g., almost instantaneously), attempting to provide a large, approximately instantaneous demand can cause one or more parameters of the electrical output of generator 42 (e.g., frequency and / or voltage) to decrease. Predictor circuit 39 at least partially pre-compensates for this degradation / decrease in electrical parameters in response to large demand. Furthermore, predictor circuit 39 can be enabled and activated at any time to prepare for large current surges to motor 44 (e.g., AC motors).

[0023] As previously stated, the techniques described herein can be applied to systems that include two or more turbines. Figure 3 This is a perspective view of a gas turbine system 50 with two gas turbines operating in parallel with each other. During operation of the gas turbine system 50, multiple generators (which convert energy from gas turbine engines 52, 54) can be connected to a bus to power motor 44 or load 12. Some loads may require excessive power from one generator and / or one gas turbine. Multiple generators operating in parallel on the bus can help meet large power demands, and a sharp increase in power demand may occur in the power supply generators, such as when starting a high-power AC motor.

[0024] In operation of the gas turbine system 50, air intakes 76 and 78 draw in air (e.g., ambient air). A first air compressor 80 (e.g., one or more compression stages) of the first gas turbine engine 52 and a second air compressor 82 (e.g., one or more compression stages) of the second gas turbine engine 54 compress the drawn-in air to produce compressed air.

[0025] Combustion of fuel (such as fuel 15) within the first and second gas turbine engines 52 and 54 is performed in the respective first combustor 88 and second combustor 90. Furthermore, each combustor 88, 90 may include multiple combustion chambers. Once combustion gases are generated in the first combustor 88 and second combustor 90, they are respectively sent to the first gas turbine 92 of the first gas turbine engine 52 and the second gas turbine 94 of the second gas turbine engine 54, where work is extracted from the hot combustion gases, as described above. Figure 1 As described. The work extracted by the first gas turbine 92 and the second gas turbine 94 can cause rotation of one or more features, such as the shafts connecting the gas turbines 92, 94 to the respective loads 96 and 98. Optionally or additionally, the gas turbines 92 and 94 can drive the respective compressors 80, 82 of the first gas turbine engine 52 and the second gas turbine engine 54, as well as any other loads, such as generators, propellers, etc., by extracting work from the combustion gases generated within the combustors 88 and 90.

[0026] Although system 50 is described as having two gas turbine engines (first gas turbine engine 52 and second gas turbine engine 54), it should be noted that this method is also applicable to systems that use any number of gas turbine engines to power one or more generators.

[0027] As previously described, the corresponding gas turbine 28 and generator 42 pair may be arranged in a single device (e.g., gas turbine generator 48), or they may be independent machines interconnected. Furthermore, the gas turbine generator 48 may contain one or more control mechanisms (e.g., controller 38) to regulate various parameters (e.g., voltage, frequency, etc.) of the generator 42, the gas turbine 28, or both the generator 42 and the gas turbine 28. As previously described, the generator 42 may be electrically connected to the electric motor 44 to provide energy for its operation. Furthermore, in order to achieve efficient power transfer to the electric motor 44 to be started, the generator 42 may be configured to match the reactance and impedance of the electric motor 44 and / or other motors and loads of the system 10. Configuring the circuit elements of the generator 42 such that the reactance and impedance are matched in value allows for efficient power transfer between the generator 42 and the electric motor 44.

[0028] As previously mentioned, the gas turbine system 10 may include more than one gas turbine with more than one shaft. Since the combustion flow is constant at a given free turbine speed, a multi-shaft configuration allows for a wider range of load-bearing capacity. However, a multi-shaft, free-rotating power turbine may still have limited load-bearing capacity, especially when operating under low power demand. When the gas turbine operates at a light load and then suddenly experiences an increase in power demand (e.g., starting the electric motor 44), the generator 42 may experience a limited amount of power demand before attempting to meet the new power demand and stabilize itself, potentially leading to current saturation or excessive torque. Saturation may occur when the coils in the generator 42 are saturated with current, causing adding more current to result in energy dissipation (e.g., heat) instead of increasing the magnetic field strength. When the gas turbine attempts to provide more power to meet the increased power demand by applying excessive torque to the generator 42, excessive torque may be applied to the generator rotor. Excessive torque may damage the generator 42 or eventually cause it to shut down. For example, as will be discussed below, the frequency of the generator 42 may be reduced below a certain threshold frequency. If the frequency exceeds the threshold, the gas turbine generator 48 may be unable to stably power the electric motor 44 to which it is electrically connected, and there is a risk of saturation and / or excessive torque.

[0029] To meet high power demands, the gas turbine generator 48 can increase the operating parameters or output aspects of one or both of the gas turbine 28 and the generator 42. According to an example, the generator frequency and the output voltage of the generator 42 can be increased before power is supplied to the motor 44, which will receive power from the gas turbine generator 48. In this way, the generator 42 can be prepared for load demands, increasing its load surge capability and improving its transient speed.

[0030] Figure 4A sample curve 120 is shown plotting generator frequency versus generator power output. The generator frequency is measured in Hertz (Hz), and the generator power output is measured in Megawatts (MW). Figure 120 shows the load acceptance response of a generator with a rated frequency of 60 Hz and a voltage of 13.8 kV, and can be configured for multiple voltage and frequency options. As mentioned earlier in this discussion, when a generator receives an increased load, the increased power demand of the generator, especially during startup under low load conditions, can destabilize some parameters of the generator (e.g., frequency, current, voltage, power output, etc.). As shown in Figure 120, when the load on one or more generators 42 increases, the power output of generator 42 increases as it attempts to meet the increased power demand. In Figure 120, as the power output of generator 42 increases to meet the new demand for electricity, the frequency of generator 42 decreases, as indicated by the negative slope of line 122. The frequency of generator 42 may initially decrease due to the surge in energy transferred from generator 42. The frequency of generator 42 may correspond to the electrical frequency of the alternating currents in the generator. Furthermore, there may be a minimum threshold frequency of 124; below this minimum threshold frequency, generator 42 may fail to recover. Below the minimum threshold frequency of 124, generator 42 may saturate or experience excessive torque from the gas turbine. For example, in Figure 4 In this context, the minimum threshold frequency of 124 corresponds to 57 Hz. However, Figure 4 The minimum threshold frequency shown is for illustrative purposes and is by no means limited to a specific value, such as 57 Hz. Other minimum threshold frequencies exist based on factors including generator rated frequency, temperature, etc.

[0031] In some implementations, an AC motor (e.g., motor 44) can be started without initial angular momentum. Such a start (e.g., starting a motor lacking initial angular momentum) can utilize a large power surge to start motor 44, and then the generator 42 can be stabilized at the new demand level. To accommodate such a larger surge, the generator 42 can use a greater load surge tolerance to start motor 44 with a large power surge.

[0032] Increased load surge acceptance can be provided by pre-compensating for changes in the power parameters supplied by generator 42. Line 126 uses pre-compensation to track the output frequency of generator 42 by increasing the frequency or voltage of generator 42. For example, as shown, when generator 42 outputs power at a voltage level of 13.8 kV and a frequency level of 60 Hz, generator 42 can operate for a period of time before motor 44 starts at a voltage level of 14.1 kV and a frequency level of 62 Hz. Before starting motor 44, by increasing the frequency and voltage of the generator to operate at a threshold time (e.g., 10, 15, 20 seconds) above 1 PU (per unit) (e.g., approximately 1.03 times) PU (per unit), the power output of generator 42 increases to achieve greater load acceptance. In fact, the power output of generator 42 can reach twice the initial power output and remain stable after meeting a surge in load demand. An increase in power output in one or more aspects (e.g., frequency or voltage) can improve the load acceptance of generator 42 and accelerate the recovery of generator 42. Therefore, as previously stated, in order to start motor 44 in the absence of initial angular momentum or other conditions where a large power surge may be required by the load, predictor circuit 39 can prepare generator 42, gas turbine 28, or gas turbine generator 48 by increasing one or more of its operating parameters (e.g., frequency, voltage, etc.) before motor 44 starts. The increase in the operating parameter value of generator 42 can provide additional energy to meet load demands during startup or transient events.

[0033] Figure 5 This is a flowchart illustrating the process 150 of starting the electric motor 44 when the predictor circuit 39 is connected to the gas turbine system 10. At block 152, the controller 38 operates the gas turbine system 10 to generate electricity. At block 154, the predictor circuit 39 determines whether the electric motor 44 needs to be started. For example, the predictor circuit 39 or the controller 38 may gain access to the operating schedule of the electric motor 44. If the electric motor 44 does not need to be started, electricity generation can continue as needed. At block 156, if the electric motor 44 is about to start, at least one parameter of the generated electricity is increased. Parameters that can be increased include the frequency, voltage, or other parameters of the generated electricity. These parameters can be increased simultaneously or continuously before the generator 42 experiences increased demand. Furthermore, in some embodiments, only one parameter of the generated electricity is increased, while in other embodiments, more than one parameter is increased.

[0034] At box 158, power is supplied to motor 44 for starting after at least one parameter of the generated power is increased. The increased parameter may enable the generator 42 to provide the additional energy required to sustain the increased load demand on generator 42 during transient events. Furthermore, as previously mentioned, more than one generator 42 may be connected to a bus that travels to the motor 44 being started.

[0035] At box 160, after generator 42 has successfully met the power requirements for starting motor 44, controller 38 can determine whether a standby generator is used to start motor 44. The standby generator can provide more power than is needed to operate motor 44 and load 12. For example, when using a standby generator, it can be shut down to provide additional power before starting motor 44.

[0036] At box 162, if there is no backup generator on the bus, at least one parameter of the increased power generation at box 156 can be reduced from generator 42. At box 164, if a backup generator is used during the starting of motor 44, the backup generator can be taken offline (e.g., shut down or disconnected from the bus and wires supplying power to the motor). Note that more than one backup generator can be used during the starting of motor 44.

[0037] As mentioned earlier, when generator 42 starts supplying power to motor 44, generator 42 may be disturbed from a steady or balanced state in an attempt to meet the increased demand. Figure 6 Figure 190 shows multiple lines representing parameters of the gas turbine system 10, generator 42, and motor 44 before, during, or after a transient event of increased generator power demand.

[0038] Line 200 corresponds to the power output of generator 42. Line 204 corresponds to the power demand on generator 42 from various circuit elements electrically attached to generator 42 (e.g., load 12 and motor 44). Graph 190 shows time periods: pre-start period 194, pre-emphasis period 198, start-up period 202, and post-start-up period 206. During the pre-start period 194, generator 42 operates in steady state. During the pre-start period 194, generator 42 may operate at the corresponding rated voltage (e.g., 11.5kV or 13.8kV) depending on the rated frequency (e.g., 50Hz or 60Hz) and the time prior to motor start-up. Furthermore, generator 42 may be connected to one or more loads 12 or motors 44 and is able to maintain power demand by maintaining a relatively steady state.

[0039] According to this embodiment, during the pre-emphasis period 198, generator 42 can be controlled to increase one or more of its operating parameters in preparation for starting motor 44. The duration of the pre-emphasis period 198 corresponds to the time period prior to starting the motor, during which one or more parameters of the generated power are ramped up to a higher level to pre-compensate for any drops in one or more parameters of the generated power from one or more generators 42. This pre-emphasis period 198 can have a duration sufficient to allow generator 42 to reach an output pre-emphasis level. The output of the pre-emphasis level corresponds to the increased operating value of one or more parameters of the generated power (e.g., lines 192 and 196 in the pre-emphasis period 198). During the pre-emphasis period 198, generator 42 begins to increase its frequency (as shown on line 192) and voltage (as shown on line 196) so that the generator can operate at a level above its rated frequency before experiencing new power demand.

[0040] Furthermore, the generator's power demand and output (lines 204 and 200, respectively) can increase as the motor 44 starts during a portion of the startup period 202. The controller 38 can instruct the generator 42 to increase one or more of its operating parameters (e.g., frequency and voltage) prior to startup period 202 to pre-compensate for a drop in one or more of its operating parameters while attempting to meet the increased demand during startup period 202. During startup period 202, the frequency of the generator 42, shown by line 192, drops sharply during transient events. The frequency may drop abruptly, at least in part, because a large transfer angular momentum is needed to start the motor 44 without initial angular momentum. A large energy transfer can be used to start the motor 44 without initial angular momentum. Through a series of energy conversions, the motor 44 can acquire the energy for startup. That is, the generator 42 supplies electrical energy to the motor 44. The electrical energy received by the motor 44 from the generator 42 can be converted into rotational kinetic energy, which provides torque to the motor 44 to change (e.g., increase) the angular momentum of the motor 44. Due to the demand shown by line 200 and the combined power output shown by line 200, the voltage shown by line 196 of generator 42 also drops sharply. Generator 42 can be described as being in an unbalanced, unstable, or unstable state during startup period 202. During post-startup period 206, the increased demand for power for startup decreases from the peak level required to supply the lack of initial angular momentum in motor 44 when it starts. The increased demand during startup (startup) decreases during post-startup period 206, at least in part, due to the increased difficulty in maintaining the angular momentum of motor 44 after starting it without angular momentum (e.g., reduced torque). Therefore, it may be necessary to apply a larger torque to motor 44 from the energy generated by generator 42 to increase the angular momentum of motor 44 from the lack of initial angular momentum, rather than applying torque to motor 44 to maintain the angular momentum of motor 44 at a relatively constant finite value.

[0041] Using pre-compensation, generator 42 is better equipped to recover from event transients during startup period 202, which is designed to meet increased power demand. This is true because one or more parameters of the generated power are increased to prepare for increased power demand, thereby keeping generator 42 within operating limits. For example, pre-compensation ensures that the generator frequency does not drop below a minimum frequency threshold 124 during startup of motor 44, thus preventing generator 42 from saturating.

[0042] Typically, starting an electric motor may require more power than keeping it running, thus the motor may need a large initial power supply. Figure 6As shown, the output power increases significantly during the period between the pre-emphasis period 198 and the start-up period 202. However, after the motor gains rotational kinetic energy and angular momentum, the power output of the generator 42 may decrease, as shown in the post-start-up period 206, to track the decrease in power demand. Due to the decrease in output, other parameters of the generator, such as frequency and voltage, may also decrease.

[0043] Although the foregoing discussion focused on gas turbines driving generators, similar principles can be applied to any generator system that uses a prime mover to drive the generator. Specifically, the techniques disclosed herein can be used in any generator system that may experience large, near-instantaneous demands that could reduce at least one parameter of the electrical output from the generator system.

[0044] The specific embodiments described above have been illustrated by way of example, and it should be understood that these embodiments may be susceptible to various modifications and alternatives. It should also be understood that the claims are not intended to limit them to the specific forms disclosed, but rather to cover all modifications, equivalents, and alternatives falling within the spirit and scope of this disclosure.

[0045] The techniques proposed and claimed herein are referenced and applied to material objects and specific examples of a practical nature that significantly improve the art and are therefore not abstract, intangible, or purely theoretical. Furthermore, if any claim appended to the end of this specification contains one or more elements designated as “[perform][a function]…” or “[perform][a function] steps…”, those elements shall be interpreted in accordance with 35 USC112(f). However, for any claim containing elements designated in any other manner, such elements shall not be interpreted in accordance with 35 USC112(f).

Claims

1. A system comprising: AC electric motor; One or more gas turbine generators, the one or more gas turbine generators being configured to provide power to the AC motor; and A controller is configured to control the operation of the one or more gas turbine generators by: Determine that the power will be used to start the AC motor; After determining that the power should be used to start the AC motor, the power is boosted before starting the AC motor, wherein boosting the power includes starting an additional generator; Enhanced power is used to pre-compensate for the decrease in electrical parameters caused by the increased demand for starting the AC motor; as well as After the AC motor has finished starting, the enhanced power is reduced, wherein reducing the enhanced power includes shutting down the additional generator.

2. The system according to claim 1, wherein, Determining to start the AC motor includes receiving a schedule for starting the AC motor.

3. The system according to claim 1, wherein, The electrical parameters include the frequency of the electrical power.

4. The system according to claim 3, wherein, Enhancing the power includes enhancing the frequency.

5. The system according to claim 1, wherein, The electrical parameters include the voltage used for the electrical power.

6. The system according to claim 5, wherein, Enhancing the power includes enhancing the voltage.

7. The system according to claim 1, wherein, The controller includes a predictor circuit configured to determine when to start the AC motor and amplify the power.

8. The system according to claim 1, wherein, The controller is also configured to: Determine the reduction in power demand of the AC motor; and At least in part based on the reduction in electricity demand, one or more aspects of the reduction in electricity consumption are reduced.

9. The system according to claim 8, wherein, The start-up includes an impact start-up of the AC motor, where the AC motor has no initial inertial movement.

10. The system according to claim 8, wherein, Reducing one or more aspects of the power includes reducing the one or more aspects back to the pre-enhancement level.

11. The system according to claim 8, wherein, One or more aspects include the frequency or voltage of the electricity.

12. The system of claim 8, further comprising one or more additional loads that receive power from the turbine generator.

13. The system of claim 8, further comprising an additional gas turbine generator, wherein one or more aspects include bringing the additional gas turbine generator online, and reducing the one or more aspects includes taking the additional gas turbine generator offline.

14. A tangible, non-transitory, and computer-readable medium storing instructions, said instructions being configured, when executed by a processor, to cause the processor to: The operation of the gas turbine generator is managed to produce electricity for the AC motor. Determine that the AC motor should be started according to the planned start-up; Before starting the AC motor, at least one parameter is added to the generated power, wherein the at least one parameter for adding the generated power includes starting an additional generator; The AC motor is started using at least one parameter of the increased power generated to pre-compensate for a decrease in the at least one parameter; as well as After the AC motor has finished starting, at least one parameter is used to reduce the increase in the generated power, wherein the parameter to reduce the increase in the generated power includes shutting down the additional generator.

15. The tangible, non-transitory, and computer-readable medium of claim 14, wherein the instructions, when executed by the processor, are configured to cause the processor to: It is determined that the AC motor has reached its operating speed; and The at least one parameter is reduced by taking the auxiliary gas turbine generator offline or reducing the output of the main gas turbine generator.

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