147 results about "Energy quality" patented technology

A method combining analytic hierarchy process and fuzzy algorithm is provided to evaluate grid electricity quality, including establishing a power quality comprehensive evaluation index system, realizing a comprehensive evaluation of the grid electricity quality status and grid electricity quality in different areas and so on. The invention overcomes the limitation of traditional single-index and single-point power quality evaluation, forming a comprehensive and practical power quality evaluation index system with technical and data support provided for the safe and stable operation of electricity grid.

The invention provides a cascade megawatt photovoltaic grid-connected inverter, wherein a topology structure of the cascade megawatt photovoltaic grid-connected inverter is composed of two levels, namely a DC / DC (direct current / direct current) isolation level and a DC / AC (direct current / alternating current) output level; the structures of three phases of circuits are the same; the output ends of a power inverter group of each single-phase of DC / DC output level are connected in a star shape; the input sides of power units of each single-phase level are provided with independent PV (photovoltaic) modules of the same structure; the DC / DC isolation level comprises high-frequency DC / AC, a high-frequency transformer and high-frequency AC / DC nodes of each single-phase for realizing isolation and boosting, and reducing the consumption of a switch tube via action of a resonant soft switch; the output level power transformer set adopts a bridge type inverter circuit; and the single-phase output level power units are connected with each other in a cascade mode. Based output cascade, the device can realize megawatt grid connection; as a high-frequency chain technology is used, the traditional low frequency transformer is omitted, and the power density is high; and compared with the existing photovoltaic grid-connected inverter structure, the device provided by the invention has the advantages of high energy conversion efficiency, excellent output energy quality, certain fault-tolerant capability and the like.

The invention relates to a unified power energy quality controller based on the serial-connection multiplicity of transformers and a chain structure, which belongs to the technical filed of flexible AC transmission and distribution of an electric power system and the power electronic. The unified power quality controller comprises a single-phase serial-connection multiple transformer bank and a single-phase chain H bridge converter, wherein the transformer bank consists of m single-phase transformers which form the serial-connection multiple transformer bank together with n voltage source converters connected with n secondary windings of m single-phase transformers respectively; the single-phase chain H bridge converter is provided with n chains and is formed by connecting n DC voltage supporting units and n power source converters, and an AC port of the n-chain single-phase chain H bridge converter is directly connected with the electric fence through a reactor, m and n are signless integrals equal to or more than 2, and m is less than or equal to n. The invention can realize accurate current control, has high dynamic responding speed, and can solve the problems of the traction substation of an electrified railway that the three-phase voltage is unstable and fluctuates, the power factor is low and the harmonic pollution exists, and the like.

The invention belongs to the field of applied superconducting power electronics, and in particular relates to a synchronizing current and voltage decoupling control method of a voltage-source-type unit power factor high-temperature superconducting energy storage system converter. The control method is characterized by comprising the following steps: designing a voltage outer ring control module at a direct-current side and a current inner ring control module at an alternating-current side respectively with respect to a mathematical model of a superconducting energy storage system converter under dq synchronizing rotary coordinates; controlling an 'H'-shaped bidirectional DC-DC (direct-current to direct-current) chopper based on an SPWM (sinusoidal pulse width modulation) technology by adopting a hysteresis loop PI current closed-loop control method in a charge mode and a hysteresis loop PI voltage closed-loop control method in a discharge mode; and finally implementing the synchronizing current and voltage double-fed control method of a voltage-source-type SMES (superconducting energy storage system) converter according to the active current requirement and the current value of a superconducting magnet under the power grid unit power factor. The control method provided by the invention has the advantages of multi-stage current decoupling control, rapid response speed, easy implementation of control algorithm and the like, and the method is especially suitable for the application occasions for improving the electricity energy quality of a power grid and inhibiting the low-frequency oscillation of a power system and the like.

The invention provides a control method for stabilizing wind and light output power fluctuation through a hybrid energy storage system. The control method is characterized in that a super capacitor and a storage battery complement each other to conduct two-level stabilizing on wind and light output power, the same algorithm is adopted in two levels of stabilizing, required smooth wind and light output power, surplus capacity of an energy storage element and other data are collected and analyzed, an expectation value of the wind and light output power is calculated, and meanwhile the wind and light power fluctuation and the electrical charge state of the energy storage element are considered to conduct optimizing control on a mobile step size; finally, deviation between a wind and light output power actual value and the expectation value serves as the stabilizing target of the energy storage element, charging and discharging of an energy storage unit are controlled, and smoothness of the wind and light output power is achieved. On the basis that the highest power output of wind electricity and photoelectricity can be kept, by flexibly and rapidly controlling the storage battery and the super capacitor, stabilization of the wind and light power fluctuation is achieved, electricity energy quality is effectively improved, and the energy using ratio and admitting ability for renewable energy sources of a power grid are improved.

The invention discloses a realizing method of a coordinated control system of a secondary reheating uniflow boiler-steam turbine. The method realizes the dynamic decoupling control of a unit by use of a double direct energy-quality balance coordinated control system composed of an energy command signal of a secondary reheating steam turbine for the energy demand of a boiler and a heat signal and a ratio of fuel to water signal which respectively represent the energy and quality balance of the secondary reheating uniflow boiler. Meanwhile, the complex characteristic of the secondary reheating unit is considered, compensation links such as dynamic weighted compensation of heat of a characteristic point of the boiler, steam turbine pressure correction, asymmetric-constraint self-adaptive correction and the like are designed, and the regulating quality of thermal power plant units with secondary reheating is effectively increased.

The invention discloses a method for processing blast furnace liquid slag and recycling energy and application thereof. The method comprises the steps of setting a pipe network, setting a control device and the like, and is characterized in that a confined space is set; the blast furnace liquid slag is led into the confined space; in the confined space, the blast furnace liquid slag entered in the confined space is granulated and then is solidified by using flowing water; the slag discharging temperature of the solidified solid slag is not higher than the boiling point of the water in the confined space; and the generated solid slag is discharged from the confined space; the generated flowing water is collected from the confined space and put to use. The invention is mainly used for solving the problems of high water consumption of a blast furnace slag processing system, unavailable recycling and / or low recycling rate of heat contained in the blast furnace liquid slag of the traditional slag processing system, recycled energy quality required to be improved and the like. Besides the application to the technical fields of blast furnace liquid slag processing and energy recycling, the invention can be also applied to the technical field of sea water desalination and the like.

The invention provides a distributed type residual-heat / residual-pressure power generation system and a distributed type residual-heat / residual-pressure power generation method, which belong to the field of residual-heat / residual-pressure power generation. The distributed type residual-heat / residual-pressure power generation system comprises a single-screw expansion machine used as a prime mover and a generator driven by the single-screw expansion machine; and the distributed type residual-heat / residual-pressure power generation method comprises the work application step of the single-screw expansion machine used as the prime mover and the power generation step of the generator. The power generation system has convenient use, does not need to be controlled by a special person, carries out power generation automatically, can utilize middle / small-scale residual-heat / residual-pressure energy of most of modern production enterprises and can be widely suitable for all residual energy with different energy quality.

The invention is an energy quality controller for a traction power substation, composed of a three-phase converter and a Scott transformer, two orthogonal single-phase output power supplies are connected with two single-phase output ends of the Scott transformer, respectively, the three-phase converter connects in series with a three-phase output end of the Scott transformer, where the three-phase converter is an inverter with capacitor in parallel with the DC bus. It controls two power supply arms of the traction transformer at the same time and can effectively compensate harmonics in drawing electric network, reactive power and negative sequence current.

The invention discloses a reactive compensation configuration method, in particular relates to an active optimizing method of a generation and transmission grid including probability fluctuation power connection, and belongs to the technical field of reactive optimization of power systems. The method comprises the steps of forming a node admittance matrix in the power system, and setting initial voltage of each node; selecting control variable and state variable; building a reactive optimization change limitation mathematical model which specially includes target functions, portability characteristic limiting conditions and fluctuation characteristics limitation conditions; determining the configuration of the control variable by the stochastic particle swarm optimization based on the latin hypercube probabilistic power flow. With the adoption of the method, a reactive compensation device in the transmission grid can be effectively configured according to the power probability characteristics and fluctuation characteristics of the grid connection of a large-scale photovoltaic station, and therefore, the grid can run normally based on the probability meanings, and moreover, the voltage fluctuation of the photovoltaic power can be greatly reduced, and as a result, the voltage and electricity energy quality of the grid can be increased.

The invention discloses a method of load shedding of a floating wind turbine generator system based on semi-active structure control of a magneto rheological damper. The method includes the following steps: (1) analyzing the structure of the magneto rheological damper, obtaining a force-displacement relationship of the magneto rheological damper; (2) establishing an equation of motion of a multi-degree of freedom system of an offshore floating wind turbine generator system which is configured with the magneto rheological damper, and establishing equations of motion of the wind turbine generator system and the magneto rheological damper; (3) controlling the magneto rheological damper through a LQR controller and a Fuzzy controller so as to reduce the pitch angle of the floating wind turbine generator system and the longitudinal displacement of a nacelle. According to the invention, the method overcomes the defects of passive control and active control in structural control of a damper, requires less extra energy, requires simple apparatus and is not less susceptible to stability loss, can effectively reduce total load of the floating wind turbine generator system, guarantees stability of a platform, and further increases service life and energy quality of output electricity of a wind turbine generator.

The invention provides a variable voltage grade type current disturbance source. The variable voltage grade type current disturbance source comprises a charging resistor R1, a bypass switch KM-BP of the charging resistor R1, contactors KM1, KM2...KMn for switching a rectifier transformer tapping point, a rectifier transformer, back-to-back power units and a filtering unit which are sequentially connected; a primary winding of the rectifier transformer is a multi-tapping-joint winding, and secondary windings of the rectifier transformer are of multi-winding structure; each secondary winding is connected with one back-to-back power unit; the charging resistor is connected with a three-phase AC charging system; the filtering unit is connected with a three-phase AC system. The current disturbance source can be applied to the field of detection of an electricity energy quality testing system and other electricity energy quality treatment devices, and the outputted variable voltage can synchronously provide current disturbance to the electricity energy quality testing detecting systems at a plurality of voltage grades.

The invention discloses a controlling method of an energy feedback type diesel engine testing device. A diesel engine drives a synchronous generator to generate alternating current with variable frequency and amplitude and outputs the alternating current to a rectifier; the rectifier converts the alternating current with the variable size and frequency into direct current, and outputs the direct current to a direct current boost converter, and meanwhile, the rectifier transmits the energy output by the diesel engine to a direct current boost converter; the direct current boost converter converts the direct current voltage with variable amplitude output by the rectifier into stable direct current voltage to be used for a grid-connected inverter; the grid-connected inverter inverts the direct current output by the direct current boost converter into alternating current which is fed back to the grid through a grid-connected transformer and a switch cabinet, and the power output by the diesel engine is transmitted to the grid. Through applying the method, the testing device has the advantages of small land occupation, high electricity energy quality and low maintenance cost, so that the problems of environment control and the like caused by the waste of the energy source and the rise of the environment temperature in testing places can be avoided.

The invention relates to the technical field of electric energy quality of digital substations of an electric system, and provides a method for analyzing electric energy quality harmonic waves of a digital substation. The method comprises the first step of receiving real-time sampling data x[n] sent by a merging unit (MU) of the digital substation, the second step of carrying out software digital filtering on the received real-time sampling data x[n] to filter out higher harmonic waves and disturbing signals to obtain the system frequency, the third step of acquiring the sampling rate of the digital substation and carrying out corresponding harmonic wave and inter-harmonic wave analyzing according to the acquired sampling rate to obtain the analyzing result, and the fourth step of carrying out subsequent index operation and interface display on the electricity energy quality according to the analyzing result in the third step and sending the electricity energy to a master electricity energy quality analyzing station. The method can meet calculation demands of harmonic waves and the inter-harmonic waves under various sampling rates, the calculation amount can be greatly reduced, and the actual engineering application demands can be met.

The invention relates to a UPQC (unified power quality conditioner) based on an SCR (silicon controlled rectifier) and energy storage, and belongs to the power equipment technology field. The UPQC based on the SCR and the energy storage comprises super capacitive energy storage modules, bidirectional direct current-direct current converter modules, inverter modules and bidirectional SCR modules, wherein the super capacitive energy storage modules are connected with low voltage sides of the bidirectional direct current-direct current converter modules in parallel, high voltage sides of the bidirectional direct current-direct current converter modules are connected with direct current sides of the inverter modules in parallel, alternating current output ends of the inverter modules are connected in parallel between output ends of the bidirectional SCR modules and a load, and input ends of the bidirectional SCR modules are connected with a system power source. The UPQC based on the SCR and the energy storage enlarges a range for solving power energy quality problems, and simultaneously is further integrated, and effectively reduces cost. Furthermore, the UPQC based on the SCR and the energy storage not only has the advantages of being high in response speed, high in standby efficiency and stable in work, but also is simple in structure, convenient to maintain, easy to operate and high in cost performance, and effectively saves production cost.

The invention provides a composite energy storage and supply device via thermochemical temperature swing adsorption combined cold-heat supply, belonging to the energy technical field. The device comprises a low-grade residual heat device, a thermochemical pressure swing desorption composite energy storage device, a thermochemical temperature swing adsorption combined cold-heat supply device, two refrigerant regulating valves, a condenser and a heat exchange coil pipe for the condenser, wherein, the low-grade residual heat device is connected with the thermochemical pressure swing desorption composite energy storage device; the thermochemical pressure swing desorption composite energy storage device is connected with the inlet of a first refrigerant regulating valve; the outlet of the first refrigerant regulating valve is connected with the inlet of the condenser; the outlet of the condenser is connected with the inlet of a second refrigerant regulating valve; the exit of the second refrigerant regulating valve is connected with the thermochemical temperature swing adsorption combined cold-heat supply device; and the condenser is internally equipped with the heat exchange coil pipe for the condenser. The device is applied to energy quality improvement of low-grade residual heat / industrial waste heat and efficient recovery; and the device has the advantages of strong temperature-rise capability, high stored energy density, composite storage of heat and refrigerating capacity, and combined cold-heat supply.

Compositions containing apoaequorin and methods for their use in treating symptoms and disorders related to calcium imbalances associated with, for example, sleep quality, energy quality, mood quality, memory quality or pain are provided by the present invention.

The invention discloses an automatic adjusting and controlling device for electricity energy quality, which consists of a measuring and controlling circuit as well as a direct current excitation controllable saturable reactor (9), a harmonic filter channel (24), a capacitor compensating element (11) and a voltage balance adjusting part (18) connected in parallel, wherein a reactance coil (91) of the direct current excitation controllable saturable reactor (9) is connected in parallel with the harmonic filter channel (24) and an excitation coil (92) of the direct current excitation controllable saturable reactor is electrically connected with the output end of a controllable direct current excitation power supply (6); the output end of the measuring and controlling circuit is respectively and electrically connected with the control ends of the controllable direct current excitation power supply (6), a first switching part (15) and a second switching part (21), and is used for respectively controlling the switching of the exciting current of the excitation coil (92), the capacitor compensating element (11) and the voltage balance adjusting part (18) according to the detected variable quantity. The automatic adjusting and controlling device for electricity energy quality can automatically adjust the power factors of a power grid, implement reactive compensation, eliminate harmonic waves and three phase imbalance, and can be broadly applied for guaranteeing the electricity energy quality.

The invention discloses a sub-control phase-change heat exchange system based on grading combination heat exchange. The sub-control phase-change heat exchange system comprises a flue, an air channel, an air pre-heater, an external water pipeline, a steam supply valve of a low-temperature water heater, the low-temperature water heater, a water inlet valve of the low-temperature water heater, a steam-liquid heat exchanger, a steam supply valve of the steam-liquid heat exchanger, a steam supply valve of an air channel heat exchanger, an external steam supply valve of the air channel heat exchanger, a main water draining pipeline, the air channel heat exchanger, a water tank, a water pump, a water inlet valve of a flue heat exchanger, the flue heat exchanger, and a steam outlet valve of the flue heat exchanger. According to the sub-control phase-change heat exchange system, heat release exchangers which utilize the waste heat of recycled flue gas are arranged in a grading combination mode; according to different situations such as ambient air temperature, operating conditions and the like, the waste heat can be utilized to heat boiler supplied air, condensed water on the side of a steam turbine and the like in a combination mode; meanwhile, the temperature of the condensed water is improved through grading heating, higher energy quality is obtained, and the optimal economic benefit of recycling the waste heat is achieved.

The present invention belongs to an energy management system used for a fertilizer enterprise. The energy management system comprises a DCS system, a PLC system, an SCADA system, an ERP system and an intelligent instrument which are connected with an OPC server separately. The OPC server is connected with a data acquisition unit, the data acquisition unit is connected with a data processing unit via a data storage unit, and the data processing unit is connected with an energy consumption balance modeling unit and an online monitoring webpage unit separately. The energy consumption balance modeling unit separately displays, via the online monitoring webpage unit, a yield consumption plan management display module, a production resource management control display module, an equipment energy efficiency diagnosis optimization display module, an energy consumption actual performance display module, an energy quality display module, an energy consumption analysis display module, an energy consumption cost display module, an environmental protection emission index monitoring display module, a danger source monitoring display module, an emergency management platform display module and a knowledge base management display module. The energy management system used for the fertilizer enterprise has the advantage of realizing the dynamic energy management of the fertilizer enterprise.

The invention relates to a phase change heat storage solar air source dual-heat-source heat pump hot water power generation system. The heat pump hot water power generation system comprises a refrigerant circulation system, a water source heating system and a power generation system body. A photovoltaic panel and a heat collection evaporator are combined together, the heat of the photovoltaic panel is absorbed through phase change heat storage materials, and a refrigerant continuously and stably absorbs the heat of the solar photovoltaic panel in the heat collection evaporator to be evaporated. On one hand, the effect of cooling the photovoltaic panel is achieved, the photoelectric conversion efficiency of the photovoltaic panel is improved, and the photoelectric panel stably outputs electric energy. On the other hand, the effect of collecting the heat of the photovoltaic panel is achieved. Solar energy absorbed by the heat collection evaporator and air heat energy absorbed by an air cooling type evaporator exchange energy with cold water in a water cooling type condenser through a heat pump system, hot water is produced, and heat energy is effectively utilized. Accordingly, the energy quality is improved, energy is effectively utilized and saved, and the phase change heat storage solar air source dual-heat-source heat pump hot water power generation system has the advantages of being stable, convenient to use and the like.

The invention discloses a client side power supply quality index calculation system based on the SMART (specific, measurable, attainable, realistic and time-based) criterion. The client side power supply quality index calculation system comprises a user, a smart electric meter and a power supply quality index calculation server and is characterized in that the smart electric meter is connected with an acquisition terminal used for wirelessly transmitting user power consumption information, and the acquisition terminal is communicated with the power supply quality index calculation server successively via a GPRS (general packet radio service) network and an Internet network. The client side power supply quality index calculation method disclosed by the invention comprises the following steps of a) collecting power consumption information; b) sending power consumption information; c) receiving and processing power consumption data; d) calculating the voltage percent of pass; e) calculating the client harmonic wave distortion rate; f) calculating three-phase voltage unbalance; g) detecting power supply reliability; and h) processing the power energy quality problem. According to the system and the calculation method disclosed by the invention, the power supply quality can be truly and objectively reflected, the power supply quality evaluation index system is established, and the real situation of the power supply reliability can be accurately reflected.

A distributed synthetic power energy quality regulation device is composed of a test circuit containing test elements, a control circuit with computing function including reactive power compensation, an operation circuit made up of each phase or each line inverse parallel transistors and a master circuit of subdivided capacitors among which, the test circuit is coupled with a network via three current mutual-inductors and three voltage mutual inductors, the control circuit is composed of a 16 bit single-chip processor of Intel and chips around, which output signal controls on-off of the operation circuit.

The invention discloses a double-fed wind power generator frequency closed-loop control experiment device which comprises a PLC (programmable logic controller), an asynchronous motor, a double-fed wind power generator, a dragging frequency changer, a power distribution cabinet, a rotor-side excitation frequency changer, an electricity energy quality analyzer and switch cabinet, a coaxial coupler and a motor support thereof. Realtime wind conditions of a weather station are collected, data are transmitted to the PLC, conditions of propeller blades and wind wheels of an actual wind power generator are simulated, the controller simulates and calculates output of the wind wheels and outputs rotating torque and rotating speed data to the dragging frequency changer, the dragging frequency changer drives the asynchronous motor to rotate, the asynchronous motor coaxially drags the power generator for power generation, a stator side of the rotor-side excitation frequency changer of the power generator is connected in a load cabinet through a protecting device, and rotor-side excitation current is acquired by calculating frequency of the motor and output frequency of a stator of the power generator. Frequency closed-loop control is realized, frequency of the stator is ensured to be output constantly, and a double-fed working mode of a rotor side is realized through a brake resistor or an energy feedback power grid.

The invention discloses an online optimization method for the thermoelectric load distribution of multiple heat supply units of a thermal power plant cluster, and belongs to the technical field of thermoelectric load distribution of heat supply units. The method solves the problems that the targeted optimization is not carried out on steam distribution of different energy qualities in thermoelectric load distribution of multiple heat supply units at the present stage, and the influence of the thermoelectric load change on the economy after steam distribution is not considered. According to thepresent invention, during the online optimization process of the thermoelectric load distribution, the type characteristics of different steam extraction units and the influence of different parameters on heat consumption are comprehensively considered, and the accurate definition of the boundary conditions of the units and the accurate calculation of the heat consumption value are achieved; during the optimization process, the boundary conditions are defined in a more multi-level mode, the speed is increased, and the local optimization is avoided; the reasonable distribution of the steam with different energy qualities and the electric power is realized under the condition that a plurality of steam extraction and heat supply units are arranged in the cluster and each steam extraction unit has a plurality of steam extraction points, and the total energy consumption is reduced. The method can be applied to the technical field of the thermoelectric load distribution of heat supply units.

The invention discloses an apparatus and method for the low-cost control of voltage sag and short-term interruption of a power grid. The method employs a double-channel power supply for solving a problem of the quick mutual switching of load power supply reliability and employs the advantages of the conventional DVR, and combines the two sides, so the apparatus can solve a problem of voltage sag and energy quality which commonly exist in the power grid, effectively guarantees the power utilization reliability of a sensitive load, solves problems that the energy storage element in a conventional voltage sag compensation device is expensive and difficult to maintain, can reduce the energy consumption, can save the installation space, can reduce the operation cost of the apparatus, and is very good in economic benefits.

This invention relates to a central heating and individual charging integration method and metering system. This invention is based on the ratio of operation charge Z and user consumption general effective heat E of the central heating system within time t to identify the price for each unit of effective heat U. And it identify each user charge of heat Y#-[m, i] according to the multiply of user consumption effective heat and each unit of effective heat price. This invention needn't alter the heating pipe and only locate a outdoor temperature 7 in the central heating area and a heating meter 3 in the entrance of m area and realizes the heat measurement of the I users consumption in the area m through heat meter 9 or heat distribution meter 6. This invention organically integrates the heat supply charge method and heat distribution charge method and imports effective heat to reflect heat supply energy quality and heat supply effect.

The invention provides an electric energy quality disturbance source judgment method based on a bird flock algorithm and an SVM. Firstly, load current data and common node voltage data in a system arecollected, correlation coefficients of load current and common node voltage waveforms are calculated according to a Pearson correlation coefficient model, and nonlinear load and linear load discrimination evaluation indexes are established; a power increment sequence and a power increment average value of each load branch are calculated in the same time period according to the power increment model, and a dynamic load and static load discrimination evaluation index are created by comparing the power increment average values; electric energy quality responsibility evaluation indexes are created under different harmonic responsibilities according to the harmonic responsibility index model; and an analysis support vector machine function model, is created, the analysis support vector machinefunction model is substituted into a bird swarm algorithm, an optimal position is outputted, an optimal function is solvedand an electric energy quality disturbance source is identified in the powerdistribution network. Important preconditions can be provided for dividing and evaluating responsibilities of each harmonic source or flicker source, and technical guarantee is provided for user sideelectric energy quality treatment work.

The invention discloses a real-time wind power predicting method based on ensemble empirical mode decomposition and a relevant vector machine. The real-time wind power predicting method is characterized by comprising the steps of obtaining and processing data, building a multi-step rolling prediction mode, building wind power prediction modules and prediction evaluating indexes of the ensemble empirical mode decomposition and the relevant vector machine, and the like. The real-time wind power predicting method has the advantages of being scientific, reasonable and capable of reducing influences brought by nonlinearity and nonstability wind power of wind power, meeting prediction precision requirements, facilitating electric power system dispatching, ensuring power energy quality, reducing the running cost, and the like.

The invention discloses a pulse width modulation method for an H-bridge cascading-type inverter, and the method comprises the following steps: setting a specific function optimization target with the minimum harmonic current, and a nonlinear constraint with the H-bridge power balance; solving an initial switching angle value of a corresponding modulation degree through employing a genetic algorithm; solving an optimal switching angle value through employing a nonlinear programming function Fmincon; carrying out the planning of switching angle values in a whole modulation ratio range, and carrying out the serialization of the switching angle values in an allowed specific function index. The method employs a multilevel synchronization optimization pulse width modulation method to effectively solve problems of energy quality at low switching frequency and the instantaneous power balance of an H-bridge module, and is successfully used in the field of AC transmission.