49 results about "Static compensator" patented technology

The present invention provides a method, computer program product, and apparatus and control system and method for providing substantially uninterrupted power to a load. The apparatus includes a control system coupled with an electrical power storage subsystem and a electrical power generator. The control system is configured to provide a plurality of modes of operation including at least a static compensator (STATCOM) mode, an uninterruptible power supply (UPS) mode and a generator mode (gen set), and to control transitions between each of the plurality of modes. In one embodiment, the control system is an integrated closed loop control system that includes a current control system and a voltage control system. The apparatus is capable of operating at least two of the plurality of modes simultaneously, including ramping the gen set mode up and simultaneously ramping the UPS mode down as the gen set mode is ramped down.

The supercapacitor-based grid fault ride-through system provides a dynamic model of a wind generation system including a Voltage Source Converter (VSC), which functions as a Static Compensator (STATCOM). The power control capability of the STATCOM is extended by incorporating energy stored in a supercapacitor. The system implements a vector control technique based on the decoupling of real and reactive power. Simulation results show that a fixed speed induction generator is capable of withstanding a significant grid fault when aided by the supercapacitor-based grid fault ride-through system. Moreover, the induction generator regains its pre-fault status immediately after the fault is cleared.

A chain-link converter including one or more phases. The one or more phases each includes one or more series-connected converter cells. The chain-link converter includes a power source connected to a converter cell of one of the one or more phases. A cost-efficient start-up of the converter is provided. The invention also relates to a corresponding static compensator system and a method.

A static compensator apparatus for a HVDC system may control harmonic wave compensation at high passive speed to meet operating characteristics of the HVDC system. A static compensator is turned-on in a normal mode and compensates for invalid power and removes a harmonic wave generated by the high voltage direct current system. A static compensator controller controls an operation of the static compensator. A diesel power generator operates complementarily to the static compensator and being turned-on when the high voltage direct current system starts.

The invention relates to a transformerless STATCOM (Static Compensator) topological structure based on MMC (Modular Multilevel Converter), which comprises three phases; each phase is formed by connecting standard power units of a plurality of modular multilevel converters in series; after series connection, one ends of the standard power units are connected one another, and the other ends are connected with an inductor; the inductor is connected with a charging resistor; and after being connected with a switch in parallel, the charging resistor is accessed to a power grid via another switch. The standard power units adopt the charging resistor and a capacitance to supply DC side voltage. The invention has the advantages that by adopting the structure, a transformer parallel in a traditional STATCOM can be omitted, and therefore achieving the purposes of cost reduction, space saving and simple structure.

The invention relates to an STATCOM control method based on a multi-model fuzzy neural network PI. The method comprises the steps of S1, dividing the distribution system into three models, i,e., Mi (i=1, 2, 3) according to the reduced amplitude value of the voltage Upcc of an access point after a load side of a distribution system is connected with different impact loads; S2, designing a d-axis PI controller PIdi (i=1, 2, 3) and a q-axis PI cotroller PIqi (i=1, 2, 3) for each of models; and S3, enabling the fuzzy neural network model to comprises a fuzzy controller and a neural network. Control parameters kp and ki of the the d-axis PI controller PIdi (i=1, 2, 3) and the q-axis PI cotroller PIqi (i=1, 2, 3) in the Mi (i=1, 2, 3) are adjusted through the fuzzy neural network model. The method has the advantages that 10, the PI controller adopts a multi-model technology, and PI parameters are selected according to a model index in the technology, so that the PI controllers can adapt to the changes of the load of the access point; and 2), the control parameters kp and ki are adjusted by the fuzzy neural network, and complex workload caused by manual PI parameter adjustment is reduced greatly.

The invention discloses a chained static compensator (STATCOM) direct-current-side voltage controlling method and a chained STATCOM direct-current-side voltage controlling circuit based on a voltage-sharing capacitor. The chained STATCOM direct-current-side voltage controlling circuit comprises a three-phase star-shaped connection inverter, the voltage-sharing capacitor, n bidirectional switch devices, a sensor and a microprocessor, wherein output voltage of each inversion circuit module of the three-phase inverter is detected by the sensor and is output to the microprocessor; the microprocessor is used for controlling connection/disconnection of the n bidirectional switch devices until direct-current-side capacitor voltage of each phase is balanced. By adding a small-volume auxiliary circuit, energy of each current-side capacitor of a chained STATCOM is renewedly distributed, so that the capacitor voltage keeps stable and balanced, and the key problem that the STATCOM is limited to be used in a high-pressure large-volume occasion is effectively and reliably solved; and therefore, the reliability of a system is greatly improved, and the cost of voltage-sharing control is obviously reduced so as to propel that the chained STATCOM is reliably applied to medium-high pressure high-volume power devices.

The invention discloses an integrated static compensator of a distribution transformer, comprising the distribution transformer, a static compensation module and a control platform, wherein each phase winding at a high-pressure side of the distribution transformer is provided with a connecting tap; the connecting tap is connected with an alternating current output side of the static compensation module; and the control platform controls the static compensation module to inject reactive power by the connecting tap so as to realize compensation. The integrated static compensator centralizes to compensate at a key node, thus improving the capacity of the static compensator of existing distribution networks and improving the quality of compensated output waveform.

The invention discloses a series compensation device. The device comprises at least two voltage source current converters, at least two three-phase transformers, and at least one three-phase electric reactor; the voltage source current converters are connected to a multi-loop line in series through the three-phase transformers, and the AC sides of the voltage source current converters are connected with one another through the three-phase electric reactors, thereby realizing the function of equally dividing system flow by the plurality of current converters. The device scheme provided by the application can be independently installed in a power transmission system to be used as a static synchronous series compensator, and can also be used as a component of a unified flow controller, a convertible static compensator, an inter-line flow controller and a unified power quality regulator to be connected to a power transmission system device in series. The device is capable of saving the capacity of the current converters, the application efficiency of the series compensation device is improved, and the cost and the floor area are reduced.

The invention provides a convertible static compensator applicable to a plurality of lines. As for N lines, the convertible static compensator comprises at least one parallel connection transformer, N current converters, a back brake loop and at least N series connection transformers, at least one side of each series connection transformer is in parallel connection with at least one by-pass switch, alternating current sides of the current converters are connected with the at least one parallel connection transformer through the back brake loop to be connected into an alternating current system, meanwhile, an alternating current side of each current converter is connected with at least one series connection transformer through the back brake loop, the series connection transformers are in series connection to be connected into corresponding lines, and direct current sides of the current converters are connected to a direct current bus or mutually connected through change-over switches. By means of the convertible static compensator applicable to the plurality of lines, various operating modes can be achieved, line power flow and system alternating voltage controls can be simultaneously or separately achieved, and excellent flexibility and economical efficiency can be achieved.

The invention relates to an inverter grounding system. Inverters are inverters of the MMC, or inverters of H-bridge cascade connection, or inverters of a flying capacitor or inverters of a diode clamper. The system comprises the inverters with the direct current sides being connected. The alternating-current side of one of the inverters is connected with a power system through a transformer in parallel. The alternating-current side of the inverter is connected with a star-connection electric reactor in parallel. The alternating side of the other inverter is connected with the system in series through connection with another transformer. According to the technical scheme, according to the characteristic of an MMC technology, a unified power flow controller is fully considered, and to solve the special problem that a star-shaped grounding mode cannot be adopted for a convertible static compensator, a unified power quality conditioner and other parallel connection transformer valve side windings, an inverter grounding mode suitable for the unified power flow controller, the convertible static compensator and the unified power quality adjuster are researched and proposed.

The invention relates to a converter grounding system. Converters are MMC converters or H-bridge cascade converters or converters with flying capacitors or converters with diode clamps. The converter grounding system comprises converters connected with a DC side, wherein an AC side of one converter is connected with an electric system in parallel through one transformer, an overvoltage protecting device and a grounding device are arranged on a winding of a valve side of the transformer, the AC side of the other converter is connected with the system in series through the other transformer, and an overvoltage protecting device and a grounding device are arranged on a winding of a valve side of the other transformer. By means of the technical scheme, according to the characteristics of an MMC technology, the converter grounding system which is suitable for a unified power-flow controller, a convertible static compensator and a unified power quality conditioner is researched and put forward.

The invention provides a STATCOM (static compensator) control method based on a switching system theory, which comprises the following steps of: analyzing a main circuit topological structure of an STATCOM device, and determining a mathematical model of a singe unit-infinite system comprising a STATCOM, determining a three-order model of a generator in the singe unit-infinite system comprising the STATCOM, and a state equation and an output equation of an electric power system comprising the STATCOM; linearizing a nonlinear model of the STATCOM; determining the design steps of an H infinity robust controller mathematical model of the STATCOM and a generator excitation robust controller; and determining the structural composition of the whole system of the STATCOM based on a DSP (Digital Signal Processor). A controller designed according to the method of the invention can ensure that the system is stabilized on one hand when the system fails, and can eliminate the influence of the interference on the performance of the system on the other hand.

The invention discloses a serial compensation device for multiple circuits. The serial compensation device comprises at least one voltage source converter, at least two serial transformers and at least one multiple-winding transformer, wherein one sides of the at least two serial transformers are in parallel connection; the other sides are serially connected with the multiple circuits; the alternating current side of the voltage source converter is connected with a parallel side bus bar of the serial transformers through the multiple-winding transformer, so that a power flow function of one or more converter averaging system is realized. The device provided by the invention can be independently mounted on a power transmission system and serve as a static synchronous serial compensator and also can be served as a constituent part of a unified power flow controller, a convertible static compensator, a space power flow controller and a unified power quality regulator in serial connection with the power transmission system device. The device can save the capacity of the converter, can increase the application efficiency of the serial compensation device and can reduce cost and occupied area.

The invention relates to a harmonic suppression device of a submerged arc furnace and comprises a three-phase compensation circuit which is respectively connected with a secondary side of a furnace transformer through a short network of a compensation system; wherein, the short network of the compensation system is serially connected with a quick fuse and a reactance; each phase of the three-phase compensation circuit comprises a capacitor which is connected with the short network of the compensation system by a link lead to form a static compensator. The device can greatly reduce the influences of harmonics and improves the production efficiency.

The invention discloses a capacitor split type static compensator circuit with a zero-sequence voltage-sharing bridge arm and a method, belonging to the field of compensation technology of a three-phase low-voltage power distribution system. The capacitor split type static compensator circuit with the zero-sequence voltage-sharing bridge arm comprises a low-voltage power distribution network, a capacitor split type static compensator, a zero-sequence voltage-sharing inductor L<0> and the zero-sequence voltage-sharing bridge arm, wherein the zero-sequence voltage-sharing bridge arm is arrangedbetween and connected with a positive bus p and a negative bus n of the static compensator; the zero-sequence voltage-sharing inductor L<0> is bridged between the midpoint o1 of a split capacitor C<1>and a split capacitor C<2> and the midpoint o<2> of the zero-sequence voltage-sharing bridge arm; and the midpoint o<1> of the two split capacitors C<1> and C<2> is connected to the neutral point ofthe low-voltage power distribution network. According to the capacitor split static compensator circuit with the zero-sequence voltage-sharing bridge arm and the voltage-sharing method thereof, the problems of imbalance and fluctuation of voltage of the two split capacitors caused by zero-sequence compensation current are solved.