32results about How to "Stable voltage and frequency" patented technology

The invention discloses a renewable energy source cooling, heating and power microgrid system and a control method. The renewable energy source cooling, heating and power microgrid system comprises a power module and a cooling/heating module. According to the power module, a solar power generation system is sequentially connected with a DC/DC converter and a DC/AC converter in series and then connected with an AC bus, a wind power generation system is sequentially connected with an AC/DC converter and a DC/AC converter and then connected with the AC bus, a gas internal combustion generation system is directly connected with the AC bus, a storage battery pack is connected with the AC bus through a bi-directional DC/AC converter, variable power electricity storage hot water tanks are connected with the AC bus, and the AC bus is connected with a power distribution network through a PCC. The renewable energy source cooling, heating and power microgrid system and the control method have the advantages that clean renewable energy sources such as methane, wind energy and solar energy are adopted as energy sources of a cooling, heating and power microgrid, no pollution is caused to the environment, operation cost is very low, and the application range is wide; by the adoption of a multi-microsource energy supply mode, the problem of capacity allocation redundancy of a single energy supply system can be solved.

The invention discloses a power grid black-start method with participation of regional small hydropower stations and new energy hybrid micro-grids. A process of the method includes selecting black-start micro-grids; selecting the optimal starting paths; starting the micro-grids; charging lines; transmitting power to loads; outwardly expanding and starting started power sources; interconnecting the micro-grids with systems. Energy storage systems in the micro-grids are used as black-start power sources when the micro-grids are started and run in V-F modes, so that voltages can be assuredly generated for buses of the micro-grids; present voltage frequency stability of the micro-grids can be guaranteed by means of invoking active power and reactive power which are outputted by the energy storage systems when the small hydropower stations and photovoltaic systems in the micro-grids are started. The power grid black-start method has the advantages that merits of simple auxiliary equipment, low auxiliary power consumption, high starting speeds and the like of the micro-grids are sufficiently utilized by the power grid black-start method, the micro-grids are used as the black-start power sources for power grids, accordingly, power failure durations of the power grids can be shortened, and normal running of the power grids can be restored as soon as possible; the power grid black-start method is applicable to black-start of the regional small hydropower stations and the new energy hybrid micro-grids.

The invention discloses an on-vehicle easy-maintenance voltage transformer error calibration system and a method thereof. The on-vehicle easy-maintenance voltage transformer error calibration system and the method belong to the technical field of mutual inductor testing. The on-vehicle easy-maintenance voltage transformer error calibration system provided by the invention comprises an on-vehicle platform on which a standard voltage transformer, a test booster and a test box are arranged. The standard voltage transformer is an infrared epoxy barrel type standard voltage transformer. The test booster is an infrared epoxy barrel type standard test booster. A voltage regulating control power supply is fixedly arranged in the test box. The test box is internally provided with a mutual inductor calibrator, a voltage load box, a remote controller and a connecting line. A multi-combined compensating reactor is arranged in the voltage regulating control power supply. The error calibration system provided by the invention can be used for field calibration of a 500kV-220kV voltage transformer. The height of on-vehicle system in a transportation state is only 2.2m. The on-vehicle easy-maintenance voltage transformer error calibration system has advantages of facilitating mobile transportation and traceablility maintenance, realizing high safety and high efficiency in use, and obtaining high stability and high reliability of the error data of the standard voltage transformer.

The invention discloses an independent microgrid mixed control method and system based on combination of peer-to-peer control and intensive control. The independent microgrid comprises various distributed power sources and is connected with a microgrid central control center. The independent microgrid mixed control method includes (1) controlling parallel operation of master control power sources in the independent microgrid by peer-to-peer control; (2) balancing and optimizing discrete control activity of the distributed power source from the overall angle by intensive control. The invention further discloses an independent microgrid mixed control system based on combination of peer-to-peer control and intensive control. The independent microgrid mixed control method and system based on combination of peer-to-peer control and intensive control solves the problem of coordinative control of various types and numbers of distributed power sources in the independent microgrid system, stability in voltage and frequency in system operation is guaranteed, and optimal operation and maximized value of the system are improved.

The invention discloses a comprehensive power management device for vehicle-mounted experiments. The comprehensive power management device for vehicle-mounted experiments comprises a shell, a displaymodule, a conversion module and a connector assembly, wherein the shell comprises a shell body structure, a cabinet door, a front panel, a left panel, a right panel, a rear panel and an inner isolating board; the display module comprises a display screen, an indication lamp and a state monitor; the conversion module comprises a conversion switch, an inverter and an UPS; and the connector assemblycomprises an aviation plug and a triplex socket. The comprehensive power management device for vehicle-mounted experiments can be used for conditions of the absence of mains supply, such as long-timeoutdoor operations or long-distance vehicle-mounted experiments, and simultaneously can mainly satisfy high-quality power requirement of precision experiment equipment. For the comprehensive power management device for vehicle-mounted experiments, the point is that the inverter, the conversion switch and the UPS are combined, a direct current of a storage battery is converted into a 220V 50Hz alternating current and output, meanwhile, a function of changing the storage battery without cutting off the alternating current output and an emergency short-time power supply function are provided, thecomplete device is designed in a modularized form, small in size, low-cost and convenient to popularize and maintain.

The invention discloses a method for controlling frequency stabilization of a permanent magnet wind-driven generator capable of adapting to changing torque. The generator directly obtains a stable voltage frequency in the process of converting mechanical energy into electric energy by the method. The method obtains the voltage frequency of the generator by a frequency stabilization control system, and controls the opening and closing of a stator winding switch by an ADRC according to difference between the voltage frequency of the generator and a rated value to further control the number of the windings connected and adjust the rotating speed of the generator so as to adjust the voltage frequency of the generator and keep the voltage frequency of the generator stable.

An undisturbed switching-based multi-target running optimal control method of a microgrid comprises the steps of 1, allowing each running mode to have respective controller with regard to a multi-moderunning switching system; 2, seeking admissible control Alpha <*> (t), and allowing a performance index function (3) to take minimum value according to an optimal control theory; 3, considering a control target of an island running mode as simultaneous average power for suppressing circulation; and 4, considering a running target of the microgrid under a grid-connected running mode, and designinga corresponding mode controller and an undisturbed switching compensation controller during switching from the island running mode to the grid-connected running mode. With the undisturbed switching compensation controller designed by the invention, the stability of the system and smooth and continuous transient-state performance can be ensured.

The invention discloses a micro-grid harmonic suppression method based on a synchronous inversion technology. Firstly, according to a voltage output model of a micro-source inverter in a micro-grid, a harmonic suppression method is researched by analyzing a harmonic generation reason and a voltage quality deterioration mechanism in the micro-grid in an isolated island operation state; secondly, according to the reason and mechanism of harmonic generation, the harmonic is suppressed by adopting a control strategy of combining a synchronous inverter and frequency division suppression, and the relationship between each system parameter of the synchronous inverter and active power P and reactive power Q is obtained by analyzing the mathematical model of the synchronous generator; a synchronous inverter control module with frequency and voltage control and active and reactive power regulation is designed; according to voltage information of a system, after d-q conversion and a low-pass filter, harmonic components of different frequencies of system voltage are extracted, and a harmonic frequency division suppression control module is designed based on a harmonic frequency division suppression algorithm.

The invention discloses a wireless sensor network-based distributed energy microgrid power control system. The wireless sensor network-based distributed energy microgrid power control system comprisesa lower energy transmission network and an upper wireless sensor communication network, wherein the lower energy transmission network comprises loads and distributed power supplies; controllable nodes are used for collecting the power, the load and other information of controllable distributed power supplies and loads corresponding thereto, receiving information transmitted by surrounding controllable or semi-controllable nodes, and performing output power and load balancing coordinated control on the system according to the collected information. Under the condition that the stability of thecontrol system is guaranteed, a wireless sensor network is introduced, a photovoltaic power generation device, a wind power generation device and a battery energy storage device are used as main controlled objects, and the wireless sensor network-based distributed energy microgrid control system is established, so that the wireless sensor network-based distributed energy microgrid power control system is suitable for any topological structure and has high flexibility and scalability.

The invention discloses a high-stability infrared anti-theft alarming system based on buffer protection. The high-stability infrared anti-theft alarming system is characterized by mainly comprising an alarm BL, a photoelectric coupler U, a triode VT3, a triode VT4, a triode VT5, a triode VT7 and a resistor R6, wherein the resistor R6 is connected between an emitter of the triode VT3 and a second input end of the photoelectric coupler U in series. The high-stability infrared anti-theft alarming system has high resistance to common mode interference, can effectively suppress interference without being affected by electromagnetic interference of the system itself, is higher in stability when compared with the traditional infrared alarming system, and can improve an alarming accuracy rate to 95% or above on the basis that the existing alarming accuracy rate is only 80% when compared with the situation that the traditional infrared alarming system is prone to generate a false alarm.

The invention discloses a surge protection-based flickering-prevention table lamp control system. The surge protection-based flickering-prevention table lamp control system is characterized by mainlycomprising a time-based chip U, a bidirectional thyristor VS and a diode D6, wherein a P pole of the diode D6 is connected with ground, and an N pole of the diode D6 is connected with a second positive electrode of the bidirectional thyristor VS via a resistor R14. The surge protection-based flickering-prevention table lamp control system has a reminding function, a lamp can be automatically turned off after a certain time when a person reads with the table lamp, so that the person is reminded of needing a rest, and eyes are protected; and meanwhile, the table lamp control system can give outweak light at night, so that the person is prompted of the position of the table lamp, and the person is convenient to use the table lamp. The table lamp control system has a surge protection functionand can be used for suppressing a surge voltage, so that the table lamp control system is prevented from being damaged by the surge voltage.

The invention discloses a single-phase converter control method and apparatus. An active current calibration parameter K<d> and a reactive current calibration parameter K<q> are obtained according toan angular speed of a power grid side voltage of the current control period; by combination with K<d> and K<q>, an active current and a reactive current are calibrated; by combination with a power grid side active current reference value and a power grid side reactive current reference value, active current deviation delta i<d> and reactive current deviation delta i<q> can be obtained; an output voltage u<ab>(k) is obtained according to the delta i<d> and delta i<q>, and the u<ab>(k) is subjected to pulse width modulation to obtain driving pulse of each switching tube in the single-phase converter; and the power grid side parameters can be adjusted by controlling the on-off of the switching tubes. According to the single-phase converter control method, the active current and the reactive current can be calibrated through the angular speed of the power grid side voltage; and equivalently, the active power and the reactive power are adjusted through the power grid side voltage frequency,so that the allocation of the active power and reactive power can satisfy requirements of an electric power system in a condition that the voltage frequency is changed, thereby improving active and reactive power adjustment accuracy and stability in the electric power system.

The invention relates to an offshore wind power plant flexible direct current power transmission system and a black start method. The system comprises an offshore wind power plant current collection group, an offshore booster station, a sending end converter station and a receiving end converter station which are electrically connected in sequence. A hybrid energy storage module is arranged in the offshore wind power plant current collection group; the hybrid energy storage module comprises a power type energy storage element and an energy type energy storage element, the power type energy storage element is used for establishing the voltage and frequency of the power transmission system, and the energy type energy storage element is used for stabilizing the voltage and frequency of the power transmission system.

The invention discloses a frequency-modulated constant-voltage output power supply based on a high-voltage absorption circuit, which is characterized in that: a transformer T, a diode D1, and a triode VT5 are respectively connected to the primary-side inductance coil L1 and the primary-side inductance coil L2 of the transformer T. Connected base trigger circuit and so on. The present invention can monitor the input voltage and adjust the voltage in real time to keep the voltage within a constant range. In this way, even if the mains fluctuates, the present invention can also output a constant voltage; the present invention can also adjust the voltage frequency Adjustment is made to make the frequency of the output voltage more stable, so that the present invention can better supply power to electronic equipment. At the same time, the present invention can also absorb the induced voltage on the transformer coil when the power is cut off, prevent high voltage from breaking down the electronic components in the system, and improve the safety performance of the present invention.