30results about How to "Improve grid stability" patented technology

A family of power converters has input ac voltage regulation instead of output dc voltage regulation. The bi-directional converters control power flows and maintain the input ac voltage at or close to a certain reference value. These bi-directional power converters handle both active and reactive power while maintaining the input ac voltage within a small tolerance. Use of these converters is favorable for future power grid maintenance in that they (i) ensure the load demand follows power generation and (ii) provide distributed stability support for the power grid. The converters can be used in future smart loads that help stabilize the power grid.

A method is provided for operating a controller controlling an energy production plant including plural wind turbines each having an electrical output terminal connected to a common node. The method involves determining that a failure relating to the energy production plant has been overcome; receiving a first signal indicative of an actual value of an electrical quantity at the common node; receiving a second signal relating to a desired value of the electrical quantity at the common node; generating plural reference signals based on an intermediate value between the actual value and the desired value; and supplying the reference signals to the wind turbines, the reference signals controlling the wind turbines with respect to their electrical output at the output terminal such that the intermediate value of the electrical quantity at the common node is achieved.

An energy balancing system is provided that ensures continuous energy output to compensate for energy fluctuations commonly associated with wind power generation. The flexible energy balancing system employs a base load high-pressure steam boiler that is associated with one or more steam turbine generators. The steam turbine generators are also associated with one or more heat recovery steam generators whose temperature is controlled by the exhaust from combustion turbine generators and the base load high-pressure steam boiler. The energy balancing system can be selectively tuned to quickly compensate for energy fluctuations associated with wind power generation.

The invention belongs to the technical field of methods for improving the fault ride-through capability of renewable energy stations, and particularly relates to a method for improving the active support control fault ride-through capability based on virtual impedance FCL. The method comprises the following steps of formulating an active support control strategy of a renewable energy field station; formulating an emergency voltage control strategy of the renewable energy field station; and analyzing the low-voltage ride-through capability of the renewable energy field station in a three-phasesymmetric fault state. According to the invention, the grid-connected stability of the renewable energy field station can be improved, the severe influence on a phase locking result due to the use ofa PLL (phase locked loop) in a three-phase symmetric fault state of the system is avoided, so that the renewable energy field station has the characteristic of flexibility and controllability, and theeffect of low-voltage ride through of the renewable energy field station under the three-phase symmetric faults of different degrees is achieved. When a fault occurs, the grid-connected operation ofthe renewable energy field station is not interrupted, and the complex synchronous operation process of reconnecting to the system is avoided. The method does not need the extra hardware equipment, and has the characteristics of flexibility and low cost.

Inverter control device is provided. First correcting-signal providing unit of the inverter control device provides a signal reflecting an active power correcting signal. Active power control unit of the inverter control device generates an angle control signal reflecting an output voltage phase of an inverter. Second correcting-signal providing unit of the inverter control device provides a signal reflecting a reactive power correcting signal. Reactive power control unit of the inverter control device generates a control signal reflecting an output voltage amplitude of the inverter. Processing unit of the inverter control device receives a feedback signal reflecting an output current of the inverter, a feedback signal reflecting an output voltage of the inverter, the angle control signal, and the control signal, and outputs a signal reflecting the active power of the inverter, a signal reflecting the reactive power of the inverter, and a voltage command signal.

The invention discloses a multi-inverter system grid connection stability control method based on power detection under a weak power grid. In order to solve the stability problem of multi-inverter grid connection under a weak power grid, the multi-inverter system grid connection stability control method based on power detection under weak power grid is provided. According to the method, the output active power of each grid connected inverter is detected, the inverters, of which the ratio of output active power to the rated active power is smaller than a set boundary value, in a multi-inverter system are obtained, and the proportion and integral control parameter of the current regulator of the inverters are reduced, so that the grid connection stability of the entire multi-inverter system is improved. The implementation is easy, the stability margin of the multi-inverter system under the weak power grid is greatly increased, and the power grid adaptability of the multi-inverter system is improved.

The invention discloses a method for MGP new energy grid-connected control, wherein, the synchronous motor is connected to a synchronous generator; the new energy module drives the synchronous motor to rotate through a frequency converter; the frequency converter controls the power transmission; and the synchronous motor drives the synchronous generator for grid connection. The present invention has the beneficial effects that: the control method and system provided by the invention can improve the stability and reliability of the grid.

The invention provides a power grid frequency modulation device applied to a photovoltaic direct current side. The device comprises an energy storage connecting terminal, a low-voltage direct-currentbus, a charging circuit, a discharging circuit, a high-voltage direct-current bus, a charging and discharging connecting terminal and a controller, wherein the energy storage connecting terminal is used for connecting an energy storage battery, a charging and discharging control unit is used for connecting a photovoltaic module and a photovoltaic inverter in parallel, the charging circuit and thedischarging circuit are connected in parallel between the low-voltage direct-current bus and the high-voltage direct-current bus, the energy storage connecting terminal is conductively connected withthe low-voltage direct-current bus, and the charging and discharging control unit is connected with the high-voltage direct-current bus, and the controller is connected with the charging circuit and the discharging circuit and used for controlling the charging circuit and the discharging circuit to work. When the device is applied to a photovoltaic power grid, the upper limit and the lower limit of adjustment of the photovoltaic inverter can be improved, moreover, the power grid frequency modulation device applied to the photovoltaic direct-current side is applied to the photovoltaic direct-current side, and the device is simple to install and low in cost, and facilitates transformation of a photovoltaic power grid in the prior art.

The invention discloses a solar-energy parking shed system capable of achieving wireless charging and discharging. The solar-energy parking shed system comprises a solar panel arranged at the top end of a parking shed, parking space charging and discharging devices and vehicular charging and discharging devices, wherein each vehicular charging and discharging device comprises a second magnetic coupling coil, a charging and discharging controller and a storage battery; each parking space charging and discharging device comprises an energy converter and a first magnetic coupling coil, and the energy converter is used for converting input electric energy into high-frequency electric energy which is output to the first magnetic coupling coil or converting the electric energy generated by the electromagnetic resonance coupling of the first magnetic coupling coil into alternating currents which are connected into a power grid; the first magnetic coupling coils and the second magnetic coupling coils are used for generating electromagnetic fields through electromagnetic resonance to receive or transmit electric energy. The solar-energy parking shed system has the advantages that the bidirectional energy storage inverter technology is used, solar energy resources are sufficiently first, and electric vehicles are charged through wireless magnetic coupling resonance; meanwhile, power grid stability is increased through the energy storage and peak, plain and valley regulating effects of the electric vehicles.

The invention discloses a fast controller for a high-speed switch, and the method comprises the following steps: S1, connecting a debugging module with an upper computer, and carrying out the debugging and detection of the controller; s2, detecting and recording set values of zero-sequence current i01, A-phase line current ia1 and C-phase line current ic1; s3, zero-sequence current i02, A-phase line current ia2 and C-phase line current ic2 are collected and recorded in real time and compared with set values; and S4, transmitting a comparison result to a central processing unit, lighting a specified indicator lamp according to the result, and indicating personnel to troubleshoot according to the indication. According to the quick controller for the high-speed switch, through the arranged controller structure, when a fault occurs, short-circuit current is judged within two milliseconds, signal transmission and fault guidance are carried out through the state indicator lamp, and when a one-way grounding fault and an interphase short-circuit fault occur, switch-on and switch-off of the switch can be quickly controlled; and the switch body structure is matched to shorten the circuit fault duration and improve the power grid stability.

The embodiment of the invention provides an enhanced and depletion type integrated power device and a manufacturing method thereof. The enhanced and depletion type integrated power device comprises asubstrate, and an enhanced power device and a depletion type power device which are formed on the substrate. The enhanced power device comprises a first epitaxial structure, a P-type nitride layer which grows on the first epitaxial structure via the first epitaxial growth, and a first N-type semiconductor layer and a first P-type semiconductor layer which are formed on the first epitaxial structure through the second epitaxial growth. The depletion type power device comprises a second epitaxial structure, and a second N-type semiconductor layer and a second P-type semiconductor layer which areformed on the second epitaxial structure through second epitaxial growth. Therefore, based on a charge balance structure of the N-type semiconductor layer and the P-type semiconductor layer formed bythe secondary epitaxial growth, the interface state of the P-type nitride layer after etching is optimized, the excellent saturation current characteristics are obtained, the charge balance structurecan be used as a gate dielectric layer of a depletion type power device, and the gate stability of the depletion type power device is improved.

The invention discloses a multi-target cooperative control method for a doubly-fed wind power generation system under harmonic power grid voltage. The method relates to the control of a grid-side converter and a rotor-side converter. Harmonic current instruction values of different control targets of the rotor-side converter and the grid-side converter of the doubly-fed wind power generation system are calculated respectively; under the condition of different harmonic distortion rates of the power grid voltage, a control target is selected according to the active power output range of the doubly-fed wind power generation system; the electromagnetic torque ripple of the doubly-fed wind power generation system is obviously inhibited, the pulsation of the total output active power and reactive power of the doubly-fed wind power generation system is inhibited, the output electric energy quality of the system is improved, the operation safety of a transmission shaft system is protected, theservice life of the transmission shaft system is prolonged, and the operation and maintenance cost is reduced.

The invention provides an active damping stabilization control method for a dual-active bridge type micro-inverter, which realizes two active damping stabilization control suitable for different conditions by respectively adopting two modes of connecting an inductor in series with a virtual resistor active damping controller and connecting a capacitor in parallel with the virtual resistor active damping controller. By sampling the voltage of a filter capacitor, connecting a virtual resistor to a grid-side output filter inductor in series or connecting virtual resistors to two ends of the filter capacitor in parallel, and setting a feedback item based on the characteristic of phase shift control of the dual-active bridge type micro-inverter, the grid-connected stability of the micro-inverter is greatly improved, and the total harmonic distortion (THD) of output current is improved. According to the invention, active damping in the control loop is adopted, so that the problems of loss and heat dissipation caused by passive damping are eliminated; meanwhile, the feedback coefficient of the active damping can be flexibly adjusted, so that the active damping stabilization control method can be suitable for different circuit parameters and circuit working conditions and has good universality.

There is provided methods and apparatus configured to provide electrical converter control parameters, the apparatus comprising: a Structured H-infinity tuning module configured to determine one or more control parameters, for a model of an electrical converter control system and grid, based on variation of one or more grid parameters; and an output module configured to provide the one or more control parameters for implementation in the electrical converter control system.