Integration of Power Grids with Wind Turbines

Self-regulating wind turbine generator that can adjust output voltage without mechanical components like blade pitch control or yaw systems. The generator has a rotor spinning with the wind turbine and a stator that can move inside the rotor's magnetic field. An actuator moves the stator closer to the rotor to increase voltage below a threshold and farther away to limit voltage above the threshold. This self-regulation allows maximum voltage extraction without overloading the system in high winds.

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Control method for wind turbines configured as virtual synchronous machines (VSMs) to improve grid stability and reduce mechanical loads after faults. The method involves controlling the wind turbine's power output based on the synchronous machine angle, using high-pass filtered rotational speed to determine damping power. It also uses comparisons of DC link voltage and grid power to determine chopper power. This allows the wind turbine to provide grid-forming properties similar to a synchronous generator while avoiding power oscillations and excessive mechanical loads after faults.

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Controlling wind turbine power output during frequency events on the grid to avoid the "wind-up" issue where the set point from the grid controller exceeds the turbine's output limits. During grid frequency deviations, the turbine's active power reference is set to the limit if the calculated reference is outside it. After the deviation, the reference ramps back to baseline instead of waiting for the set point to reach the limit. This ensures the turbine's output matches the reference during deviations and ramps immediately after, avoiding delays.

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A wind farm design with onsite hydrogen production and export to mitigate power fluctuations and avoid long-distance transmission costs. The wind turbines have electrolysis units to generate hydrogen using excess wind power. The hydrogen is exported via a shared above-sea-level manifold rather than subsea connections. This allows easier maintenance and prevents corrosion compared to underwater connections. The manifold connects the turbine hydrogen outputs to a common pipeline for transporting the hydrogen produced by the wind farm. This eliminates the need for individual subsea connections from each turbine. The manifold can be housed in a container or installed at the turbine platform or tower.

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Wind turbine with integrated harmonic filters to reduce harmonic distortion in wind farm electrical grids. The filters are mounted inside the turbine tower instead of at the substation. This eliminates the need for large external filters at the farm level, reducing cost and footprint. The filters connect to the high voltage side of the main transformer inside the turbine. When a turbine is disconnected from the grid, the filter remains connected to dampen harmonics on the remaining turbines.

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Optimizing power generation in a wind farm by dynamically adjusting the operating parameters of individual wind turbines based on local wind shear conditions. The method involves measuring or predicting the vertical wind shear profile above the wind farm. This profile is then used to determine optimal adjustments to turbine settings like blade pitch, rotor speed, and yaw angle. These adjustments are made in real-time to optimize overall farm power production considering the non-standard wind shear profile and turbine interactions.

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Superconducting direct drive generator for wind turbines that can generate higher electrical power than conventional generators while reducing weight and size for easier installation on tall towers. The generator has a stationary coil wound around a composite torque tube and a rotating armature. The torque tube supports the stationary coil and prevents rotational motion. This allows a compact, lightweight generator that can be mounted directly on the wind turbine hub without gearboxes or heavy rotor masses. The superconducting coils provide high torque density. The composite torque tube reduces weight compared to solid steel.

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A pipeline power generation system that uses compressed air storage and multi-stage wind turbines in a sealed pipe to reduce the cost of peak shaving power compared to conventional methods. The system stores excess low-demand electricity in compressed air, then releases it through a sealed pipe with multiple wind turbines of decreasing size. The high-speed compressed air flows through the turbines, converting kinetic energy into electricity as wind speed decreases. Mixing atomized water with the air further improves generation efficiency. Multiple parallel systems can be connected to increase total peak power capacity.

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Operating wind turbines to charge auxiliary power sources during low wind conditions instead of idling the main generator. When certain conditions are met, the turbine blades are pitched to a fixed angle for idling. If wind speed exceeds a threshold, the rotor spins to charge the auxiliary power sources without generating main power. This avoids wasting power keeping the main generator running at low speeds.

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A stability evaluation method and system for direct-drive wind turbine generators that allows online assessment and parameter adjustment to improve stability of the system. The method involves calculating the energy gradient at the wind turbine terminal using voltage, current, and angle measurements. A negative energy gradient indicates instability. The gradient is influenced by factors like PLL parameters, wind turbine current levels, and transmission line resistance. By understanding these relationships, the method proposes adjustments to critical parameters like PLL gains and wind turbine current limits to improve stability.

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A modular multi-turbine wind power system that improves efficiency and durability compared to single-turbine systems. The system uses a toroidal support structure with concave and convex sections. A turbine travels around the concave section, surrounded by baffles that adjust the flow of air. This allows each turbine to rotate to the most efficient position relative to the wind. A control system optimizes turbine positioning based on wind data. The toroidal shape and baffles also reduce noise and damage risks. The system can switch between power generation and resistance modes based on wind speed.

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Method to improve reactive power capability of wind turbines with doubly-fed induction generators (DFIGs) by intelligently managing generator speed in low wind conditions. The method involves transitioning to a secondary operational mode when certain parameters like rotor speed drop below thresholds. In this mode, the turbine increases generator speed at the expense of active power production. This allows maintaining reactive power capability in low wind conditions where DFIGs have limited reactive power capacity. The mode is selectable by command. The method balances maximizing active power versus reactive power capability.

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A hybrid wind power system that uses vertical axis wind turbines to compress air for a gas turbine power generation cycle. The system avoids the limitations of large horizontal axis wind turbines by using vertical axis turbines that can handle variable winds better. The vertical axis turbines directly drive compressors to compress air, which is then expanded through a gas turbine to generate electricity. This allows on-demand power generation near loads instead of relying on remote wind farms. The hybrid system also includes intercooling between compression stages to achieve higher pressure ratios for more power extraction.

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A system for generating high frequency switching signals to enable higher voltage output from power converters in power generation systems like wind turbines without the need for bulky transformers. The system uses a control device with multiplexing, integration, modulation, and generation stages to convert a low frequency PWM signal into a higher frequency PWM signal. This allows operating the converters at higher switching frequencies to directly couple the converter output to the stator voltage instead of using a separate transformer.

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Controlling a wind turbine during grid faults to allow ride-through capability while preventing excessive mechanical loads. The technique involves dynamically adjusting the drivetrain damping settings based on the number of grid faults. For the first fault, the damping is tuned for power performance. For subsequent faults, the damping is adjusted to prioritize reducing mechanical loads. This allows the turbine to ride through multiple faults without tripping, while preventing excessive loads during prolonged fault sequences.

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Control module for a wind power converter that emulates the behavior of a synchronous generator to improve grid stability. The converter is controlled to behave like a synchronous machine even when connected to the grid. The module calculates a power change based on the converter output power and sets a new power target accordingly. This compensates for network errors and maintains stability. It allows converter-based generators to operate like synchronous machines without losing converter benefits. The module has a power calculation circuit and a setpoint adjustment circuit.

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Method and apparatus for controlling renewable energy generation to provide constant frequency power at variable loads. It uses a voltage regulator with feedback from the load and feedforward from the renewable source to maintain output frequency. This allows maximizing baseload power from fluctuating renewables like wind and water. The regulator replaces mechanical speed converters in motor equivalent generators. It replaces variable voltage transformers in MG sets. The regulator connects between the renewable source and load, using a servo motor to adjust voltage for constant frequency.

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A method to avoid tripping of wind turbines caused by excessive currents in the power electronic converter. The method involves temporarily increasing the generator speed above nominal if certain operational parameters indicate potential converter tripping. This reduces converter currents and avoids tripping. The generator speed is then lowered back to nominal once the parameters indicate converter operation is safe again.

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Fast frequency response method for wind turbines to improve grid stability by utilizing inertial energy stored in the turbine rotor to quickly arrest frequency drops after grid disturbances. The method involves overproducing power from the turbine in response to grid frequency changes, which slows the rotor. A dynamic adaptive gain adjusts the overproduction level based on wind speed and penetration to optimize grid support. This prevents large frequency overshoots and dips compared to fixed gains.

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Wind turbines with integrated harmonic filters to reduce harmonics in wind farm electrical grids without needing a separate filter at the substation. The filters are placed inside the turbine's support structure and connected to the high voltage side of the main transformer. This allows damping harmonics in the medium voltage lines of the wind farm grid. The turbine generator can be disconnected during grid faults while the filter remains connected to continue damping.

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Operating a wind turbine's power converter to smoothly reduce power output during grid abnormalities without damaging the generator. The method involves separately controlling the line-side converter connected to the grid and the machine-side converter connected to the generator. When grid abnormalities require power reduction, the line-side converter reduces grid output. The machine-side converter reduces generator torque to match the lower grid power. If the generator power falls below grid power, excess power is dissipated in resistors. This allows separate, coordinated power setpoints for the grid and generator converters during grid abnormalities to prevent generator damage.

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Ducted wind turbine designed for offshore environments to generate electricity from wind and waves. The ducted turbine has a nacelle enclosed in a streamlined fairing that reduces drag and noise compared to open-rotor turbines. The fairing also protects the rotor blades from wave impact. The turbine is mounted on a floating platform or can be land-based. The platform provides stability and wave energy capture. The ducted turbine allows operating in stronger winds and waves compared to open-rotor turbines. The fairing shape reduces power loss from turbulence. The platform has stabilizing arms and legs to dampen motion. The turbine can be shut down during extreme conditions. The ducted turbine and platform design enables higher power output from offshore turbines compared to open-rotor turbines.

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Efficient and scalable system for producing electricity using a combination of wind power, water pumping, and hydroelectric generation. The system involves using a wind turbine to turn a pump that increases the pressure of water from a source. This pressurized water is then fed to a conventional hydroelectric turbine to generate electricity. The pump can be assisted by energy storage systems like batteries or solar panels. The exhaust water from the hydroelectric turbine can be returned to the source to continuously cycle the water. This allows using wind power to enhance hydroelectric generation, as well as providing 24/7 operation compared to just wind power.

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Data-driven wind farm frequency control method based on dynamic mode decomposition for high-rate wind power integration into grids. The method allows wind farms to participate in grid frequency response without needing complete models of the turbines. It uses dynamic mode decomposition to find accurate low-dimensional models of the wind turbine dynamics. These models are then used in a frequency control algorithm to calculate optimal frequency corrections for the wind farm. This allows fast, data-driven frequency response without relying on complex turbine models.

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A matrix wind farm design for offshore wind power generation that allows efficient energy extraction and transport from multiple turbines. The farm uses a floating rig with openings for interchangeable turbines to be inserted and moved into position at the front of the rig. The turbines have larger propeller diameters than the rig openings, allowing them to fully rotate. This eliminates unproductive wind gaps between turbines. The rig provides a fixed platform for the turbines to extract wind energy. Electricity is transported internally through the rig instead of using external cables, reducing losses. The rig has compartments for converting and transforming the electricity before exiting the rig to connect to shore grids.

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Modular power conversion system for integrating distributed power generation, storage, and dispersed loads into a flexible smart grid, microgrid, or microgrid clusters. The system allows any power production device to connect to any load or grid. It uses interchangeable modules with power electronics to convert power between resources. This enables aggregating and converting low-level producers like wind turbines, Stirling engines, diesel gensets, or solar arrays into standard grid voltages. The modules can also handle storage, transmission, and synchronization for smart grids.

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A control method for wind turbine generators using multiple sub-rectifiers instead of a single rectifier. The sub-rectifiers are connected in parallel and share a common DC link. The control strategy involves coordinating switching of the sub-rectifiers based on the overall generator current rather than individually controlling each sub-rectifier's partial current. This reduces circulating currents by avoiding hysteresis band conflicts. The method includes delay times, deviation detection, and dynamic correlations between switching and current to optimize control. A central system generates and transmits control signals to the sub-rectifiers.

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Method for controlling wind turbines configured as virtual synchronous machines to provide improved grid stability and reduce mechanical loads. It involves determining the virtual synchronous machine rotational speed and angle based on factors like feedback damping power, power reference, grid power, and chopper power. The damping power is derived from the virtual synchronous machine rotational speed using an inertial integration model. The turbine's power output is then controlled based on the synchronous machine angle, which provides grid-forming capabilities.

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Wind turbine control strategy for grid faults that allows the turbine to ride through low voltage events without disconnecting. The strategy involves using different damping settings for the drivetrain in response to single versus multiple low voltage grid events. For a first event, settings prioritize power performance. For subsequent events, settings prioritize reducing mechanical loads to prevent tripping. This allows the turbine to stay connected during multiple events without exceeding limits.

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Fast active power reduction (FPR) system for wind turbine generators (WTGs) that allows rapid power reduction to mitigate grid issues like congestion and faults without damaging the WTG. The FPR system uses a pitch servo, DC link, rotor-side converter (RSC), grid-side converter (GSC), and DC chopper. It coordinates with the WTG's existing MPPT controller. The DC chopper has a power switching device driven by a PI controller and PWM modem. The chopper's duty cycle is controlled to absorb excess power during FPR. The pitch angle is rapidly adjusted before FPR to minimize unbalanced energy. This switches off the chopper and reduces cost compared to continuously absorbing power during FPR.

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Control method for virtual synchronous machines (VSMs) like wind turbines to improve grid integration by mitigating impedance issues. The method involves compensating the VSM output voltage reference for capacitor voltage feedback. This is done by feeding forward the measured filter capacitor voltages to counteract their effect on the VSM impedance spectrum. The filtered capacitor voltages are transformed to a target frame, combined with the voltage reference, and transformed back to the measurement frame to generate the compensated voltage reference. This compensated reference is used to control the VSM instead of the raw filter capacitor voltages.

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A lightweight, high power superconducting generator for wind turbines that can be mounted directly on the tower top and coupled to the rotating blades. The generator has a stationary field winding coaxial to the rotating armature, separated by a gap. The field winding uses superconducting coils and is supported by a composite torque tube that reduces weight and allows the generator to be mounted on the tower. The composite torque tube provides a non-rotating structure for the stationary field winding.

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Coordinated control of parallel converter modules in wind power installations to prevent circulating currents while maximizing power output. The method involves driving the converter modules in a synchronized manner based on detected total current and virtual current. The control involves changing switch positions of converter modules to superpose currents and maintain power balance. The coordinated control prevents circulating currents by avoiding negative total current.

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Reducing oscillatory response of reactive power output from wind turbine generators with integrated reactive compensation devices. The method decouples reactive power control from voltage control for the generator and compensation device. This involves operating the compensation device in a separate reactive power control mode that doesn't interfere with the generator voltage control. By segregating the control actions, it eliminates interactions that cause oscillations in the reactive power output.

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Optimizing wind turbine recovery from voltage dips on the grid to prevent excessive torque peaks that can damage drivetrain components. The method involves selecting an appropriate torque profile based on the acceleration of the generator rotor at the end of the voltage dip. This allows rapid power recovery while avoiding torsional loads that could damage the drivetrain.

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Wind turbine generator system with low-impedance superconducting generator and current source converter to enable high efficiency and fault protection for superconducting machines. The system uses a current source converter instead of a voltage source converter to drive the low-impedance generator. The current source converter has capacitors to absorb high frequency current ripple and reduce ripple in the generator coils. It also has a crowbar circuit to short the converter in case of internal faults, isolating the generator from the converter fault.

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Enhancing power generation from hybrid power systems with multiple power sources like wind turbines and solar panels. The system uses parallel converters connected by a DC link. A controller switches elements between the rotor and line converters based on operating conditions to optimize power extraction. When primary power is low, parallel converters extract more from secondary sources like solar. When primary power is high, the parallel converters are bypassed for higher efficiency. This allows extracting more total power and integrating more secondary sources.

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A modular wind turbine system that allows flexible electrical networking and enables optimized output from short runs of modules while also enabling long linear runs or interconnected networks. The system uses conductive members as structural rails to support the turbines. Each module has a collection circuit from the turbine generators connected to a concatenated transmission circuit formed by connecting the modules. This allows each module to feed electricity to the transmission line for transmission to other modules. This allows flexibility in configuring short and long runs of modules, with individual modules optimized separately via inverters, while still enabling power collection from the interconnected network.

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Decentralized reactive power compensation for wind power generation sites to improve voltage control and reduce power losses. It enables full utilization of the reactive power regulation capability of devices like wind turbine generators and static compensators. The method involves calculating a target reactive power value based on site electrical parameters, then allocating regulation to devices like turbines and compensators. This decentralized approach leverages existing reactive devices in the site for optimal voltage control without centralized compensation devices.

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Control module for converters in wind turbines to emulate the behavior of a synchronous generator. The module calculates a power change based on detected converter output power. It then adjusts the converter power set point based on this calculated change. This allows the converter to mimic the stability characteristics of a synchronous machine in response to network disturbances.

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Modular power conversion system for distributed power generation, storage, and consumption in a smart grid. The system uses interchangeable modules to convert electricity between different resources like solar panels, wind turbines, batteries, and buildings. It allows flexible integration of dispersed power sources into grids and microgrids. The modules contain power electronics for converting voltage, phase, frequency, and direction between resources. This allows smart grid features like net metering, backup power, and prioritized generation from dispersed sources. The modules also have diagnostics, annotation, and scheduling to optimize operation.

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Operating inverter-based resources like wind turbines to mitigate high currents during grid faults and resonance events without disabling the converter. The method involves monitoring both current and voltage magnitudes. If current increases while voltage decreases, converter gating is disabled to allow fast dissipation of stored energy. But if voltage decreases while current increases, gating is not disabled as converter control actions can mitigate high currents in this case. This distinguishes between events where dissipating stored energy vs external energy.

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Decentralized reactive power control for wind power generation sites that allows full utilization of on-site reactive devices like wind turbine generators and compensators. The method involves a central control device communicating with the turbines and reactive devices to allocate reactive power based on target values calculated from grid parameters. This enables coordinated, optimized reactive power control using local devices rather than relying on central compensation equipment. The control device also monitors grid conditions, turbine performance, and device capabilities to manage reactive power, voltages, and safety regions.

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Reducing oscillations in reactive power output from a wind turbine's reactive compensation device and generator when supplying real and reactive power to the grid. The method involves decoupling reactive power control and voltage control between the generator and reactive compensation device. This is done by independently controlling reactive power of the system and generator terminal voltage using separate controllers. This reduces oscillations in reactive power output from the reactive compensation device and generator compared to operating both in voltage control mode.

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Method and system to accurately account for electricity contributions from distributed local generation sources like solar panels and wind turbines when they feed back into the grid. The method involves encrypting and signing measurements of power generation and consumption from each local facility. This data is decrypted and verified at a central accounting server. By tracking power contributions and compensating facilities based on their measured outputs, it ensures fair and secure recognition of local generation without being subject to the grid provider's lower rates.

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Method for wind turbines to recover from low voltage or zero voltage grid events while meeting grid code requirements. The method involves detecting the end of the grid event, determining the rotor acceleration at that point, and then increasing the generator torque using a predetermined torque profile selected based on the rotor acceleration. This allows controlled recovery of power production that complies with grid codes while avoiding high torque peaks that could damage the drivetrain.

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A stability evaluation method and system for direct-drive wind turbine generators that allows real-time online assessment and parameter adjustment to improve stability. The method involves calculating the energy gradient at the turbine terminal using voltage, current, and power variations. This gradient reflects system stability. It is analyzed to determine how PLL and transmission line parameters impact stability. Adjustment laws are proposed to improve stability by modifying critical parameters like PLL bandwidth and turbine current levels.

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Operating a wind turbine power converter during grid abnormalities to maintain grid compliance and prevent turbine shutdown. The method involves separately adjusting the power setpoints for the line-side and machine-side converters in response to grid conditions. If grid active power needs to be reduced, the line-side converter is set accordingly. The machine-side converter is set to produce the desired generator active power by reducing torque. Any excess power is dissipated in resistors until the machine-side converter setpoint matches the line-side setpoint. This allows independent power adjustment for grid compliance without impacting turbine operation.

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Enhancing frequency support capability of wind turbines to stabilize grids with high penetration of wind power. It uses a supercapacitor energy storage system connected to the DC buses of the wind turbine converter. When the grid frequency drops, the supercapacitor provides additional torque to the generator to help bring the frequency back up. This avoids the need for the turbine to stall and reduces the frequency swings. The supercapacitor can also provide inertia support by extracting rotational energy during frequency recovery.

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Wind turbine generator system that reduces cost by using a line-commutated rectifier (LCR) instead of a force-commutated voltage source converter (VSC) in the wind turbine power conversion system. The LCR, which uses fixed diodes instead of switch-mode semiconductors, is simpler, cheaper, and more reliable than a VSC. The LCR is connected to the generator and converts the generator's AC power to DC. This DC is then transformed up by an online tap changer (OLTC) transformer to the grid voltage level. By using an LCR instead of a VSC, the wind turbine generator system can lower cost while still providing full grid compliance through the OLTC transformer.

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