196 results about "Distributed generator" patented technology

An electric power supply apparatus includes a distributed power generator such as a gas turbine generator and a power converter such as an inverter apparatus for converting electric power generated by the distributed power generator into AC electric power (alternating-current power) having a required frequency and a required voltage and supplying the AC electric power to a load. The electric power supply apparatus further includes a control unit having output voltage vs. output current characteristics for determining an output voltage corresponding to an output current of the power converter. The output voltage vs. output current characteristics has a first dropping characteristic for causing output electric power of the electric generator to be limited, between a first output current exceeding a power generation capability of the electric generator and a second output current exceeding a power converting capability of the power converter.

The invention provides a method and system for operating a solar farm inverter as a Flexible AC Transmission System (FACTS) device—a STATCOM—for voltage control. The solar farm inverter can provide voltage regulation, damping enhancement, stability improvement and other benefits provided by FACTS devices. In one embodiment, the solar farm operating as a STATCOM at night is employed to increase the connectivity of neighbouring wind farms that produce peak power at night due to high winds, but are unable to connect due to voltage regulation issues. The present invention can also operate during the day because there remains inverter capacity after real power export by the solar farm. Additional auxiliary controllers are incorporated in the solar farm inverter to enhance damping and stability, and provide other benefits provided by FACTS devices.

A method and apparatus for indicating a disconnection within a Distributed Generator (DG). In one embodiment, the apparatus comprises an alarm module electrically coupled to a conductive portion of a component within the DG, wherein the conductive portion is grounded via a ground rod system, and wherein the alarm module (i) is further coupled to a ground line, (ii) couples a monitoring current to the conductive portion, (iii) monitors flow of the monitoring current to determine a change in the flow, and (iv) generates, as a result of the change in the flow, a notification of the disconnection.

A power electronics interface in a microsource controller allows efficient connection in a power system of small, low cost and reliable distributed generators such as microturbines, fuel cells and photovoltaic. Power electronics provide the control and flexibility to insure stable operation for large numbers of distributed generators. The power electronics controls are designed to insure that new generators can be added to the system without modification of existing equipment. A collection of sources and loads can connect to or isolate from the utility grid in a rapid and seamless fashion, each inverter can respond effectively to load changes without requiring data from other sources, and voltage sag and system imbalances can be corrected.

The invention discloses a microgrid running optimization system and method based on power and heat combined dispatching. Running restrains such as the output force characteristic, start, stop and climbing of a distributed type generator set and the charge and discharge characteristics of power and heat energy storage are comprehensively considered, a microgrid power and heat combined dispatching model containing a fan, a photovoltaic cell, a combined heat and power generation system, an electric boiler, a fuel cell and an energy storage (electrical energy storage and heat energy storage) is built, the 0-1 mixed integer nonlinear programming method is adopted for solving the optimal output force and total running cost of all units in the network, and power and heat dispatching contrastive analysis is carried out on the system and a traditional separated generation and combined generation optimization model. In addition, the influences of the heat and power reliability difference on the running are analyzed and discussed, and therefore the heat and power dispatching module is more reasonable, comprehensive and universal.

Methods and systems for power management include determining a voltage level of a grid; if the voltage level is below a lower voltage threshold, setting power outputs for one or more distributed generators on the grid to maximum; and if the voltage level is above the lower voltage threshold and below an upper voltage threshold, determining power outputs for one or more distributed generators on the grid using sensitivity-based distributed Q compensation.

An active power distribution network soft normally open point (SNOP) planning method considering distributed generator characteristics is disclosed. The active power distribution network soft normally open point planning method comprises the steps of inputting corresponding parameters according to a chosen power distribution system separately; obtaining a soft normally open point planning scene and corresponding probability considering wind and light uncertainty; establishing an active power distribution network soft normally open point planning problem mathematical model according to the given power distribution system parameters and the generated planning scene; performing cone model conversion on nonlinear constraints in the active power distribution network soft normally open point planning problem mathematical model according to a standard form of cone planning; generating a soft normally open point planning scheme, optimizing the running state of each scene and calculating an upper layer target function value and a lower layer target function layer; analyzing the adaptability of the generated scheme, if the generated scheme is not the optimal solution, continuing to generate a soft normally open point planning scheme; and if the generated scheme is the optimal solution, outputting the result. The active power distribution network SNOP (soft normally open point) planning problem solving considering the distributed generator characteristics is realized; the planning result is better in adaptability; and the solving efficiency is effectively improved on the premise of ensuring the optimal solution.

A computer-implemented method for controlling voltage fluctuations of a microgrid including a plurality of distributed generators (DGs) is presented. The computer-implemented method includes collecting, by a resiliency controller including at least a voltage control module, measurement data from the microgrid, using, by a reactive power estimator, reactive power estimations to calculate an amount of reactive power for each of the DGs, and using a dynamic droop control unit to distribute the reactive power to each of the DGs of the microgrid.

The invention discloses a distributed generator islanding detection method based on impedance measurement, the principle utilizes the feature that a great change of system equivalent impedance occurs in DG synchronization and isolated network states, high-frequency voltage signals are injected at a synchronization contact point, and impedance change can be reflected by measuring voltage change, thus judging whether the system is connected with a large grid at present. In theory, the method is not influenced by load, has nothing to do with characteristics of a DG synchronization inverter, the DG number in the island in an islanding state and the topological state of a power grid, has easy realization of self-adaption setting and does not need coordination relationships. Experiment results show that the principle has excellent sensitivity, selectivity and rapidity.

An on-board Flex-Fuel H2 Generator provides devices and the methods of operating these devices to produce H2 and CO from hydrocarbons and bio-fuels. One or more parallel autothermal reformers are used to convert the fuels into H2 over the Pt group metal catalysts without external heat and power. The produced reformate is then cooled and the dry gas is compressed and stored in vessels at a pressure between 1 to 100 atmospheres. For this system, the pressure of the storage vessels and the flow control curves are used directly to control the amount of the reformers' reformate output.To improve thermal efficiency of a mobile vehicle or a distributed power generator, portion of the reformate from the storage vessels is used to mix with the primary fuels and air as part of a lean burn fuel mixture for the engine / gas turbine. Also, this on-board Flex-Fuel H2 Generator can provide H2 to regenerate the NOx and diesel particulate traps for diesel engines, and / or it can provide H2 for a mobile or a portable fuel cell power generator.

The invention discloses a composite type island detection method based on phase deviation and frequency variation. Firstly, delta theta1 and delta theta2, the motion values of two phase deviations areset, and the condition that delta theta1 is more than delta theta2 is met; when the phase deviation angle of the end voltage of a distributed generator (DG, Distributed Generator), delta theta is more than delta theta1, DG is directly judged as island operation; when delta theta is more than delta theta2 and less than delta theta1, the frequency variation value delta f is introduced as supplementary detection amount, only when the condition that delta theta is more than delta theta2 and delta f is less than delta f1 is met, delta f1 is frequency variation motion value, so that the motion of the detection device is judged as island state; the composite type motion criteria of the island detection are concluded as follows: delta theta is more than delta theta1(1) or delta theta is more thandelta theta2 and delta f is less than delta f1(2); the criterion (1) is used for island instant DG and the condition that mismatching degree of loaded active power is larger, while the criterion (2)is used for the condition that the change of the loaded active power carried by island post DG is not large, namely, the traditional phase deviation method can not detect the island state; whether DGis in the island state or not is judged by introducing frequency variation amount and combining the phase deviations and frequency variations.

A computer-implemented method for controlling voltage fluctuations of a microgrid including a plurality of distributed generators (DGs) is presented. The computer-implemented method includes collecting, by a resiliency controller, measurement data from the microgrid, using a model predictive control (MPC) module to distribute reactive power to each of the DGs of the microgrid, and using a droop based controller to guide operation of each of the DGs of the microgrid.

A method and apparatus for controlling power production. In one embodiment, the method comprises determining a predicted weather event; determining a predicted power production impact for a distributed generator (DG) array based on the predicted weather event; and controlling power production from one or more components of the DG array to compensate for the predicted power production impact.

The invention provides a virtual power plant combined heat and power scheduling robust optimization model. A model aggregation unit comprises a distributed generating set, a wind turbine generator set, a photovoltaic set, a combined heat and power (CHP) set, a boiler, electric energy storage, heat energy storage, an electric load and a heat load. Participation of the CHP set in the SRM (Spinning Reserve Market) situation is considered. Aiming at the facing uncertain problem of a virtual power plant (VPP) and resulting risks, robust optimization (RO) is utilized to process uncertainty of the EM electricity price, the SRM electricity price, the wind power capacity, the photovoltaic capacity, the electric load and the heat load, and risk quantification indexes are established, and thus robustness and economical efficiency of a RO model are balanced. The model provided by the invention well solves the existing combined heat and power scheduling optimization model establishment problem of the VPP when participating EM and SRM at the same time, and improves flexibility of decision making, and thus the profit of the VPP is increased. Meanwhile, the introduction of the RO model effectively reduces system risks, and thus the effective reference is provided for a decision maker to select a proper robust factor.

Systems, methods, and devices relating to the provision of system control support in the form of reactive power support or voltage control support to power transmission or distribution networks using inverter based power generation facilities that are coupled to the power transmission or distribution networks. An inverter based power generation facility, such as a photovoltaic based solar farm or a wind farm, can task all or a portion of its inverter capacity to provide reactive power support or voltage control support to the power transmission or distribution network. This invention applies to the operation of PV solar systems anytime during the day (even during peak power generation times) and other inverter based DGs during the entire 24-hour period. The power generation facility disconnects at least one of its power generation modules from the power transmission or distribution network and makes available required inverter capacity for providing system control support.

The invention relates to a comparative isolated island detection and protection method based on a wide range information phase difference, and belongs to the technical field of electrical power system protective relaying. According to the comparative isolated island detection and protection method based on wide range information phase difference, in the grid-connected operation processes of a distribution network system which includes distributed generators such as wind power generators, photovoltaic power generators and micro gas turbines, a feeder automation terminal in a power grid conducts real-time synchronous monitoring on voltage phases in the system. If the break variable of a voltage phase on an exit of the distributed generator is detected to be larger than a threshold value, the voltage phase difference between the voltage phase and a public coupling point is obtained through comparative analysis after certain time delay, the phase difference is compared with the setting threshold, the fact whether isolated island operation happens in the system is judged, isolated island protection is started in time, the distributed generator which is in an isolated island operation state is logged off the system. According to the comparative isolated island detection and protection method based on wide range information phase difference, the isolated island detection and isolated island protection are based on wide range information and emphasize on the utilization of the wide range information and the realization of the safety function, the effect is obvious, and reliability is high.

The present invention revolves around the incorporation and use of existing drilled wells, either dry holes, abandoned or converted producing wells and / or new, to be drilled wells or any other well(s), of any diameter and any depth, located, sited, designed and fabricated to store and cycle compressed natural gas or other gasses or hydrocarbon liquids within the contained cavity of the well-bore casing in any volume and with any degree (high or low) of deliverability.Each of the well(s) can then be incorporated with additional facilities, depending upon designed use and process (use and process as discussed within the patent application), such as standard telemetry, automation and integration equipment, compressors, pressure reducing regulators, turbo-compressors (for electrical and or mechanical power creation), distributed power generator engines, measurement equipment and other components for compressing and storing the gas or hydrocarbon liquids within the system at a range of rates, and then cycling the gas out of the well(s) for a number of business applications. The well(s) can also be incorporated with standard electronic communication devices to automate and integrate them within other systems such that they can be controlled remotely and automatically from any location.

An effective, yet relatively simple and inexpensive, method for detection of islanding in distributed power generation systems. Statistical analysis of the local line frequency, as measured at the distributed generator, is performed to detect when an island has been formed. The statistical characteristics of the local frequency are controlled by the grid when the distributed generator is not islanding. When an island is formed, however, frequency control switches to circuitry associated with the distributed generator. Because the statistical characteristics of the frequency control performed by the distributed generator are markedly different from those of the grid, the islanding condition can be detected and corrected.

A method predicts power flow in a distributed generation network of at least one distributed generator and at least one co-generator, where the network is defined by a plurality of network nonlinear equations. The method includes applying an iterative method to the plurality of network nonlinear equations to achieve a divergence from a power flow solution to the plurality of network nonlinear equations. The method also includes applying the iterative method to find a first solution to a plurality of simplified nonlinear equations homotopically related by parameterized power flow equations to the plurality of network nonlinear equations. The method further includes iteratively applying the iterative method to the parameterized power flow equations starting with the first solution to achieve the power flow solution to the plurality of network nonlinear equations.

Systems and methods for advanced energy settlements in electric power grid are proposed. At least one energy customer, at least one retail electric provider and at least one distributed generator connect to an advanced energy settlement platform communicatively. The advanced energy settlement platform is operable to summate a customer balance from all the settlement blocks during a billing period and collect payments from the at least one energy customer automatically; aggregate and settle distributed energy charges with distributed generators and fixed energy charges with the energy retailer or retail energy provider for the at least one energy customer during the billing period. The advanced energy settlement platform also provides interactive graphical user interface for different participants in the advanced energy settlement and for advanced energy settlements application development kit (ADK) for access to functionality within the advanced energy settlement platform.

A method of managing a microgrid and control system is provided, in which the virtual resistance control gains (in αβ frame) of each respective inverter is dynamically adjusted based on a variable related to the available power from each of a plurality of renewable distributed generators.

The invention relates to a multi-target optimized energy management information processing method for a virtual power plant. The method comprises the following steps of: 1) acquiring power generation information of power supplies administered by a virtual power plant company and power utilization information of power utilization users, determining credits of users according to the acquired power generation and power utilization information and the historical information of the power supplies and the users, and determining the regulating ranges of power generation quantity and power utilization quantity according to the credits by using a fuzzy function; 2) constructing a multi-target united scheduling model; 3) substituting the power generation information and the power utilization information acquired in the step 1) into the multi-target united scheduling model with a priority in the step 2), and solving with an optimization algorithm; and 4) performing multi-target optimization and priority coordinating processing. Compared with the prior art, the method has the advantages of effective optimization and management of an assembly of a distributed generator and a controllable load and the like.

A wind turbine power generation system incorporates a turbine rotor having a plurality of blades extending from a hub with each blade having an inner blade and an outer blade. A collar is provided on each blade with the inner blade extending between the hub and collar and the outer blade extending from the collar. A generator ring is carried by the collars and includes a generator rotor attached to the collars to rotate with the turbine rotor. A stator ring is supported from the generator rotor by a low friction interface for relative rotation with the generator rotor. A torque stay system prevents rotation of the stator ring for generation of power from the rotating turbine rotor as a linear distributed generator.

The invention relates to the field of relay protection containing distributed generation power systems and discloses a longitudinal differential protection scheme for an inverter interfaced distributed generator teed line. The scheme comprises steps as follows: (1) the setting values of a longitudinal protection device are initialized; (2) phase current information of lines A and B is acquired, and a three-phase voltage transformer acquires phase voltage information of buses A and B at two ends of each line and acquires positive-sequence components of voltages of the buses as well as positive-sequence components and negative-sequence components of currents of the lines; (3) home terminal information is transmitted to an opposite terminal by a communication channel, and the difference between phase currents, the difference between negative-sequence currents and the difference between positive-sequence offset voltages at two ends of each line are calculated; (4) measuring values and the setting values are compared, if one of the measuring values is larger than the corresponding setting value, a short-circuit fault is judged to occur in the protection range, and a protection outlet trips. The scheme effectively solves the problem of reduction of reliability of longitudinal differential protection for the inverter interfaced distributed generator teed line and has higher practicability in engineering practice.

A method and apparatus are provided for detecting islanding conditions for distributed generators connected to a grid. The method includes estimating a grid impedance, and inducing, on the basis of the estimated grid impedance, a variation on a value of a first electrical quantity of the grid. The method also includes monitoring a grid response to the variations, and determining islanding conditions on the basis of the monitored response.

A method and apparatus for distributed generator (DG) planning. In one embodiment, the apparatus comprises (i) at least one interface for sizing a potential DG; (ii) at least one interface for designing the potential DG; and (iii) at least one interface for generating a proposal for the potential DG.