36results about How to "Ease of commercial development" patented technology

The invention discloses a multi-infeed extra-high voltage power grid transverter wattless configuration method based on a short-circuit ratio. The extra-high voltage power grid transverter wattless configuration method comprises steps of 1) determining an object grid structure to be analyzed and related parameters, 2) arranging operation modes of an electric power system, 3) selecting a specific operation mode to calculate system load flows under different DC control modes, 4) calculating a multi-infeed short circuit ratio according to a load flow calculation result, 5) calculating a multi-infeed DC node voltage comprehensive improvement index, 6) determining a candidate node of the multi-infeed extra-high voltage DC power grid transverter wattless configuration n according to the multi-infeed DC node comprehensive improvement index, and 7) programming a single objective function optimization program according to an objective function to determine a wattless compensation capacity. The extra-high voltage power grid transverter wattless configuration method guarantees to reduce the operation cost of the power grid, guarantee the power grid to safely, reliably, economically, and efficiently operate, has significance and provides technical basis to planning design and operation control of the mmulti-infeed high voltage DC power grid.

The invention relates to a distribution network flexible load cooperative dispatching method based on a particle swarm algorithm, belonging to the technical field of grid operation and control. The method comprises the following steps of: (1) considering stabilizing new energy access, peak clipping and valley filling and safe and economical operation of distribution network, establishing an optimization objective of flexible load cooperative dispatching model of distribution network; 2, synthetically considering the system balance constraint, the network constraint, the distribution power source and the adjustable load constraint, wherein each constraint condition can flexibly carry out parameter configuration and effective setting, and establishing the constraint of the optimization objective in the step 1; and 3, finally, solving the optimization objective of the load cooperative dispatch model satisfying the constraint condition by using the particle swarm optimization algorithm. This kind of cooperative control method provides space for alleviating the peak load regulation and realizing the large-scale consumption of new energy, and its economic benefits are enormous.

An interactive game scheduling method for a park integrated energy system group and a power grid belongs to the technical field of integrated energy system operation and control, and is characterizedby comprising the following steps: (1) establishing output models and cost models of a conventional generator set, a distributed power supply, energy storage and other equipment; 2, establishing a park comprehensive energy system group and power grid collaborative optimization control framework; 3, establishing a power grid and park integrated energy system group game structure; (4) setting a threshold value, and judging whether an interactive game is performed or not; 5, establishing a park comprehensive energy system group and power grid interactive game model based on master-slave game; (6)establishing an interactive game scheduling Matlab platform of the park comprehensive energy system group and the power grid to solve an interactive process; and (7) performing simulation analysis onthe effectiveness of the interactive game scheduling strategy of the hierarchically coordinated park comprehensive energy system group and the power grid, and verifying that the interactive game scheduling strategy of the hierarchically coordinated park comprehensive energy system group and the power grid can realize stable and economic operation of the park comprehensive energy system group andthe power grid. According to the interactive game scheduling method adopted by the invention, cooperative optimization operation of the park comprehensive energy system group and the power grid can beeffectively and reliably carried out, and a technical basis and a practical method are provided for stable operation of the park comprehensive energy system group and the power grid.

The invention provides a distributed type fiber sensing device based on signal reusing perception and demodulation, comprising a laser, a first fiber coupler, a second fiber coupler, a light pulse modulator, a fiber annular device, an optical interface, a balance photoelectric detector, a low noise amplifier, a power divider, a first filter, a second filter, a frequency synthesizer, a mixer, a lowpass filter, a data collecting and processing module, and a computer. The feature that rayleigh scattering signals and Brillouin scattering signals can be generated at the same time is taken into consideration, and by means of the balance photoelectric detector, the rayleigh scattering signals and Brillouin scattering signals of the detection light pulse, generated in the detected fiber are simultaneously converted into radiofrequency signals of the corresponding frequency or frequency range. The rayleigh scattering signals and the Brillouin scattering signals are separated by means of the power divider and a band pass filter. The separated rayleigh scattering signals and the Brillouin scattering signals are accessed to the data collecting and processing module. The attenuation, vibration, and monitoring and displaying of the temperature and strain information of the fiber can be realized.

The invention discloses a flexible self-starting method for wind storage isolated network system, and belongs to the fields of grid operation and control technologies. The method is characterized by comprising the following steps: step 1) obtaining operating parameters of the wind storage isolated network system; step 2) determining the number of wind turbine units to be started; step 3) establishing a Petri network based power deviation prediction model of the wind storage isolated network system; step 4) an energy storage inverter performing master-slave control; step 5) adding power deviation control to a frequency control process; step 6) charging an inverter of the wind turbine units by using an energy storage device; step 7) the inverter starting to work to supply an excitation current to the wind turbine unit, and controling a stator voltage and a frequency converter DC voltage to reach nominal values; and step 8) incorporating the wind turbine units into an AC bus of the wind storage isolated network system. The flexible self-starting method adopted by the invention can effectively and reliably enable self-starting of the wind storage isolated network system, thereby providing a technical basis and a practical method for stable operation of the wind storage isolated network system.

The invention discloses a method for calculating the load flow of a power grid alternating current and direct current power transmission system based on direct current system control logic, and belongs to the technical field of power grid alternating current and direct current power transmission. The method is characterized by including the steps: (1) acquiring steady-state operation parameters needed for calculating the load flow of the alternating current and direct current power transmission system; (2) building direct current control logic in load flow calculation; (3) determining a direct current power transmission system control mode according to the operation state of the system and the direct current control logic; (4) calculating the load flow of the alternating current and direct current power transmission system in the determined direct current control mode; (5) drawing a calculation conclusion if calculation finishing conditions are met; and (6) switching to the step (3) if the calculation finishing conditions are not met, and continuing to perform calculation. By the method, the load flow of the alternating current and direct current power transmission system can be more effectively and reliably calculated, and a basis is provided for planning and operating the alternating current and direct current power transmission system according the control mode and the switching process of the direct current power transmission system.

The invention relates to a reactive power optimization strategy for an UHV AC / DC hybrid transmission system, belonging to the technical field of UHV AC / DC network operation and reactive power optimization. It can effectively play the role of inhibiting transient voltage rise after DC system fault, so as to reduce the number of high-voltage off-grid fans under the condition of ensuring large-scaleDC transmission. The method comprises the following steps: step 1, obtaining steady-state operation parameters required for power flow calculation of UHV AC / DC transmission system, including power ofeach power source and load point in the system, voltage of hinge point, voltage of equilibrium point and phase angle; 2, calculating the initial power flow and the initial value of the objective function of the UHV AC / DC transmission system according to the obtained operation parameters; 3, determining an objective function and a constraint condition of the steady-state operation of the system; 4,consider that objective function and the constraint conditions of the transient characteristic, and determining the constraint conditions of the generator rotor of the reactive power optimization strategy; Step 5, the particle swarm optimization algorithm is used to find the optimal solution to the obtained optimization data.

The present invention discloses a wind storage isolated network power supply system coordination control method based on flexible coordination factors, belonging to the technical field of power grid operation and control. The method comprises the following steps of: (1) obtaining operation parameters of a wind storage isolated network power supply system; (2) establishing a coordination control mechanism of the wind storage isolated network power supply system, and achieving an interbehavior between an upper layer of coordination control intelligent agent and a lower layer of unit decentralized control intelligent agent through direct and indirect effects; (3) calculating flexible coordination factors of power balance of the wind storage power supply system; (4) allowing the upper layer ofcoordination control intelligent agent to distribute the flexible coordination factors into the lower layer of unit decentralized control intelligent agent; and (5) allowing an energy storage inverter to enforce power control. The wind storage isolated network power supply system coordination control method based on flexible coordination factors can achieve coordination control of each unit of the wind storage isolated network system, ensures the stability of the output voltage and frequency of the wind storage isolated network system and provides technical basis and a practical method for stable operation of the wind storage isolated network system.

A high-energy-consumption park and power grid alternative parallel collaborative optimization scheduling method belongs to the technical field of integrated energy system operation and control, and comprises the following steps: (1) establishing output models and load prediction models of a conventional generator set, a distributed power supply, energy storage and other equipment; (2) carrying out day-ahead prediction on park side electric and thermal loads, photovoltaic output and a power grid side wind generating set; (3) establishing a park integrated energy system group and power grid decomposition collaborative optimization framework; (4) establishing a high-energy-consumption park integrated energy system and power grid parallel decomposition collaborative optimization scheduling model considering network security constraints; (5) establishing a solving process based on a parallel alternating direction multiplier method; and (6) establishing a high-energy-consumption park integrated energy system and power grid parallel decomposition collaborative optimization scheduling Matlab platform solving interaction process. The invention provides a technical basis and a practical method for stable operation and large-scale wind power consumption of the park comprehensive energy system group and the power grid.

The invention discloses an active power distribution network multi-level redundant coordinated control method considering an electric vehicle and energy storage and belongs to the new energy coordinated control technological field. The method is characterized by including the following steps that: 1, the operation data of an active distribution network are obtained; 2, the load characteristic model of the electric vehicle is established; 3, the energy storage and release characteristic model of the energy storage is established; 4, the multi-level redundant coordinated control strategy of theactive distribution network containing the electric vehicle and energy storage is constructed; and 5, the multi-level redundant coordinated control of a daily scheduling model, a hourly scheduling model and a real-time scheduling model is solved. According to the method of the invention, starting from the active distribution network, the active power distribution network multi-level redundant coordinated control method considering the electric vehicle and energy storage is researched on the basis of the idea of redundant interval division, and a promotion foundation and technical support can be provided for the further development of new energy sources such as electric vehicles.

The invention relates to the underwater active positioning field and particularly relates to an underwater two-dimensional space active electric field positioning method based on a particle swarm optimization algorithm. According to the method, a detected object is positioned through an underwater active electric field, especially for a metal object, influence of complex factors including darkness and turbidity of the underwater environment can be solved, and detection reliability and validity are improved. Starting from the basic theory of an electromagnetic field, an active electric field positioning mechanism of a light current fish is simulated, underwater positioning precision is improved to a millimeter magnitude level, moreover, a local optimal deadlock can be avoided, underwater detection validity and searching optimization are improved, the method is suitable for commercialization development, as underwater detection steps are gradually accelerated, underwater positioning technology requirements are wider and wider, and relatively good business development prospects and application values are realized.

The invention discloses a short circuit ratio-based multi-infeed ultra-high voltage direct current power grid converter reactive power configuration method. The method comprises the following steps that: step 1, adjacent date and historical load data and wind / light power generation power data are obtained; step 2, wind and light power generation power and daily load are predicted; sep 3, the equivalent daily load curve of a prediction date is constructed; step 4, the area of a wind power generation curve is calculated; step 5, heat storage capacity is calculated; step 6, an area under the loadcurve is solved through adopting a Monte-Carlo algorithm curve area solution method, and the heat storage capacity in an active power distribution network is matched with peak load; and step 7, an equal-area replacement method is adopted to reconstruct the equivalent daily load curve according to a matching result satisfying requirements. With the method provided by the invention adopted, a wind,light, storage, and heat multi-energy flexibly-complementary active power distribution load can be reconstructed more safely, economically, reliably and effectively; and a technical base and practical method can be provided for the safe, economic and efficient dispatching of the active power distribution network.

The invention belongs to an industrial park group and regional power grid coordinated comprehensive energy system planning method, belongs to the technical field of power grid operation and control, and is characterized by comprising the following steps: (1) acquiring information data of a single industrial park; (2) establishing a comprehensive energy system optimization planning model of a single industrial park; (3) acquiring information data of the whole planning area; (4), establishing a regional power grid comprehensive energy system optimization planning model; (5), establishing industrial park group and regional power grid collaborative planning constraint conditions; (6) calculating a strategy of the comprehensive energy system model based on a seagull optimization algorithm; and(7) obtaining configuration information of the system model equipment through a resolving strategy, and guiding regional energy equipment configuration construction. According to the planning method adopted by the invention, comprehensive energy system planning can be economically and reliably guided, and a technical basis and a practical method are provided for collaborative planning of industrial park groups and regional power grids.

The invention discloses an ultra-high-voltage AC power grid high-voltage reactor optimization configuration method, which comprises the steps: 1) determining a target framework structure of an ultra-high-voltage grid; 2) obtaining parameters of each electronic component in the ultra-high-voltage AC power grid; 3) establishing ultra-high-voltage power grid electromechanical transient and electromagnetic transient simulation models based on an ADPSS; 4) arranging system operation modes; 5) carrying out operating characteristic analysis on the ultra-high-voltage AC power grid having no parallel high-voltage reactors; 6) carrying out operation characteristic simulation calculation and analysis on the ultra-high-voltage power grid with installation position and compensation degree of the high-voltage reactor being taken into overall consideration; 7) calculating minimum level index of reactive play of the ultra-high-voltage AC power grid; 8) establishing an objective function according to relation of the reactive play of the ultra-high-voltage AC power grid, transmitting power and the compensation degree; 9) determining optimal compensation degree; 10) carrying out optimization configuration on the reactor of the ultra-high-voltage AC power grid; and 11) checking safety and stability of the ultra-high-voltage AC power grid. The method can be used for ultra-high-voltage AC power grid high-voltage reactor optimization configuration.

The invention belongs to the technical field of power grid operation and control, and particularly relates to a multi-stage planning method for a park integrated energy system based on a seagull optimization algorithm. A technical basis and a practical method are provided for multi-stage planning of the park comprehensive energy system. The method comprises the following steps: acquiring park integrated energy system planning information; establishing an energy coupling equipment model according to the planning information; establishing a park comprehensive energy system model; establishing a basic framework of the multi-stage planning method; establishing a park integrated energy system multi-stage planning model; establishing multi-stage planning constraint conditions of the park integrated energy system; solving the established park integrated energy system multi-stage planning model based on a seagull optimization algorithm; and through optimization calculation, obtaining multi-stage planning configuration information of the park integrated energy system based on gull-sea optimization algorithm iterative calculation, and guiding configuration construction of park energy equipment.

This invention relates to a double closed-loop control strategy of a power convertor based on particle swarm optimization, and relates to the technical field of power grid operation and control. The double closed-loop control strategy comprises the following steps: 1) carrying out double closed-loop control strategy of voltage outer loop and current inner loop to the power convertor; 2) determining the regulating range of the control parameter of the control step of the on-line adjustment; 3) monitoring a control target value; 4) if the control target is out of the allowable range, updating the control parameter by the particle swarm optimization; 5) and if the control target is in the allowable range, keeping the control parameter. The double closed-loop control strategy provided by the invention has high reliability and self-adaptability, can control the power of the power convertor under the disturbance of the power grid, and has important practical significance for improving the operation reliability and the controllability of the power convertor.

The invention belongs to the technical field of integrated energy system operation and control, and particularly relates to an integrated energy system collaborative scheduling method based on a source-load double-side interactive game. The method comprises the following steps: (1) inputting initial data, including initial electricity, gas and heat load curves, parameters of each device in a service provider and an initial energy price formulated by an energy supplier; (2) establishing a park-level integrated energy system source-load interactive game framework; (3) establishing a source-load interactive game structure of the park-level integrated energy system; (4) establishing a park-level integrated energy system multi-energy collaborative optimization scheduling model based on a source-load double-side interactive game; (5) establishing a park-level integrated energy system multi-energy collaborative optimization scheduling Matlab platform solving interaction process based on a source-load double-side interaction game; and (6) carrying out simulation analysis on the multi-energy collaborative optimization scheduling effectiveness of the park-level integrated energy system based on the source-load double-side interactive game. According to the invention, the complementation and substitution effects of various energy sources can be fully exerted.

The invention belongs to the technical field of data processing, and particularly relates to a wind power plant signal feature extraction and de-noising data optimization method. Comprising the steps of 1, obtaining wind power plant measurement signal parameters; 2, EEMD parameters in the measurement signals are obtained; step 3, establishing a Hilbert-Huang transform model of a white noise clustering empirical method according to the measured signal parameters; 4, analyzing to obtain a signal, and determining the length of a filtering window; step 5, sampling the number m of points for the analysis signal; step 6, setting the number of iterations K; 7, calculating derivative values and an average value of each point of the analysis signal sampling points; step 8, calculating and analyzing the weight of each point in the signal filtering window to de-noise each signal point; step 9, performing iteration for K times; and step 10, obtaining an accurate wind power plant analysis signal characteristic value. The method can effectively and accurately perform signal feature extraction and de-noising optimization of the wind power plant, is easy to implement, and has a wide market application prospect.

The invention belongs to the technical field of power system economy, and particularly relates to a double-layer pricing method for an energy storage aggregation platform. The method aims at a distributed energy storage and aggregation platform and a pricing mode between the aggregation platform and a power grid; in the first layer, the aggregation platform concentrates and disperses distributed energy storage and prices through a long-term contract, and in the second layer, the power grid prices different aggregators through real-time electricity prices. According to the method, the power deviation prediction model of the wind storage isolated network system is established, power and voltage regulation is implemented under the condition of considering the power deviation, and the reliability and practicability of self-starting of the wind storage isolated network system are greatly improved. According to the double-layer pricing method, pricing of the energy storage aggregation platform is effectively and reliably carried out, and a technical basis and a practical method are provided for double-layer pricing of the energy storage aggregation platform; and the distributed energy storage pricing efficiency is effectively improved, complex pricing of a large number of energy storage devices by a power grid is simplified, implementation is easy, commercialized development is facilitated, and the method has good commercial development prospects.

The invention discloses a method for calculating the load flow of a power grid alternating current and direct current power transmission system based on direct current system control logic, and belongs to the technical field of power grid alternating current and direct current power transmission. The method is characterized by including the steps: (1) acquiring steady-state operation parameters needed for calculating the load flow of the alternating current and direct current power transmission system; (2) building direct current control logic in load flow calculation; (3) determining a direct current power transmission system control mode according to the operation state of the system and the direct current control logic; (4) calculating the load flow of the alternating current and direct current power transmission system in the determined direct current control mode; (5) drawing a calculation conclusion if calculation finishing conditions are met; and (6) switching to the step (3) if the calculation finishing conditions are not met, and continuing to perform calculation. By the method, the load flow of the alternating current and direct current power transmission system can be more effectively and reliably calculated, and a basis is provided for planning and operating the alternating current and direct current power transmission system according the control mode and the switching process of the direct current power transmission system.

The present invention relates to an experiment method, especially to a wind storage isolated network system experiment method. The method performs experiment research for a whole established wind storage isolated network system in a series of experiment conditions with different states and different capacities so as to comprehensively understand the operation features of the wind storage isolatednetwork system and perform deep analysis. The method comprises the following steps of: the step 1, constructing a wind storage isolated network system experiment platform; the step 2, performing experiment for different capacity configurations of energy storage units of the wind storage isolated network system; and the step 3, performing experiment for different operation condition states of the wind storage isolated network system.

The invention relates to a flexible load coordinated dispatching method of a distribution network based on a particle swarm algorithm, and belongs to the technical field of power grid operation and control. Including the following steps: Step 1, comprehensively considering the smoothing of new energy access, peak shaving and valley filling, and safe and economic operation of the distribution network, and establishing the optimization objective of the distribution network flexible load collaborative dispatching model; Step 2, comprehensively considering the system balance constraints, network Constraints and constraints of each distribution power supply and adjustable load, each constraint condition can be flexibly configured and effective, and establish the constraint of the optimization goal in step 1; step 3, finally use the particle swarm optimization algorithm to coordinate the load that meets the constraint condition The optimization objective of the scheduling model is solved. The collaborative control method it adopts provides space for alleviating the peak load regulation of the power grid and realizing the large-scale consumption of new energy, and its economic benefits are huge.

The invention discloses a coordinated control method for an isolated wind storage grid system based on a flexible coordination factor, and belongs to the technical field of power grid operation and control. Its characteristics include the following steps: ① Obtain the operating parameters of the wind storage isolated grid power supply system; ② establish a coordinated control mechanism for the wind storage isolated grid power supply system; realize the upper coordinated control agent and the lower unit decentralized control agent through direct and indirect actions ③ Calculate the flexible coordination factor of the power balance of the wind storage isolated grid power supply system; ④ The upper layer coordination control agent distributes the flexible coordination factor to the lower energy storage unit decentralized control agent; ⑤ The energy storage inverter implements power control. The coordinated control method of the wind storage isolated grid power supply system based on the flexible coordination factor adopted in the present invention can realize the coordinated control of each unit in the wind storage isolated grid system, and ensure the stability of the output voltage and frequency of the wind storage isolated grid system. The stable operation of the isolated grid storage system provides technical basis and practical methods.

A flexible income distribution method for participating in peak regulation of a park comprehensive energy system belongs to the field of electric power economy and is characterized by comprising the following steps: (1) acquiring operating parameters of each subunit unit in the comprehensive energy system; (2) determining the peak regulation output condition of each subunit set; (3) calculating the total income according to a peak regulation compensation price mechanism; (4) accounting the cost of each subunit set of the comprehensive energy system; (5) calculating the total income of peak regulation participated by the comprehensive energy system; and (6) establishing a flexible income distribution mathematical model of the comprehensive energy system participating in peak regulation based on the Shapley value method. According to the flexible income distribution method adopted by the invention, the peak regulation income can be reasonably distributed effectively and reliably, and a technical basis and a practical method are provided for income distribution of each unit after the comprehensive energy system participates in peak regulation.

The invention belongs to the technical field of electric power economy, and particularly relates to a power generation right transaction-based tie line participation multi-source peak regulation compensation method. More units are attracted by fair and reasonable price signals to participate in peak regulation auxiliary service, and efficient utilization of new energy is promoted. The method comprises the following steps: 1, acquiring grid-connected electric quantity to be increased by a wind power generator, and determining a power generation plan in a transaction period; 2, determining a transaction subject to perform market bidding; 3, establishing a power generation right transaction model, and distributing power generation right transaction transaction electric quantity; 4, enabling the power generation right transaction market organization to perform checking work; 5, calculating the clearing price and the settlement cost; and 6, establishing a tie line participation multi-source peak regulation compensation model based on the power generation right transaction.

The invention discloses a flexible self-starting method for wind storage isolated network system, and belongs to the fields of grid operation and control technologies. The method is characterized by comprising the following steps: step 1) obtaining operating parameters of the wind storage isolated network system; step 2) determining the number of wind turbine units to be started; step 3) establishing a Petri network based power deviation prediction model of the wind storage isolated network system; step 4) an energy storage inverter performing master-slave control; step 5) adding power deviation control to a frequency control process; step 6) charging an inverter of the wind turbine units by using an energy storage device; step 7) the inverter starting to work to supply an excitation current to the wind turbine unit, and controling a stator voltage and a frequency converter DC voltage to reach nominal values; and step 8) incorporating the wind turbine units into an AC bus of the wind storage isolated network system. The flexible self-starting method adopted by the invention can effectively and reliably enable self-starting of the wind storage isolated network system, thereby providing a technical basis and a practical method for stable operation of the wind storage isolated network system.

The invention relates to the underwater active positioning field and particularly relates to an underwater two-dimensional space active electric field positioning method based on a particle swarm optimization algorithm. According to the method, a detected object is positioned through an underwater active electric field, especially for a metal object, influence of complex factors including darkness and turbidity of the underwater environment can be solved, and detection reliability and validity are improved. Starting from the basic theory of an electromagnetic field, an active electric field positioning mechanism of a light current fish is simulated, underwater positioning precision is improved to a millimeter magnitude level, moreover, a local optimal deadlock can be avoided, underwater detection validity and searching optimization are improved, the method is suitable for commercialization development, as underwater detection steps are gradually accelerated, underwater positioning technology requirements are wider and wider, and relatively good business development prospects and application values are realized.

The invention relates to a coordinated operation method of a distributed energy storage aggregation participated power grid, in particular to a distributed energy storage aggregation participated power grid peak regulation strategy under the multi-energy internet. The access capability of renewable energy sources in the power distribution network is improved, the economic benefits of the power grid and users are increased, and powerful support is provided for development of the intelligent power distribution network. The method specifically comprises the following steps: step 1, establishing a distributed energy storage aggregation participated power grid peak regulation overall control operation framework; step 2, establishing a distributed energy storage aggregation and multi-energy cooperative operation multi-objective optimization model; and step 3, performing staged optimization solution on the distributed energy storage aggregation and multi-energy cooperative operation multi-objective optimization model based on a heuristic intelligent algorithm.

The invention relates to a double-closed-loop control strategy of a power converter based on a particle swarm algorithm, and belongs to the technical field of power grid operation and control. Its features include the following steps: 1) implementing a double closed-loop control strategy of voltage outer loop and current inner loop for the power converter; 2) determining the control parameter adjustment range of the control link for online adjustment; 3) monitoring the control target value; 4) If the control target exceeds the allowable range, the particle swarm optimization algorithm is used to update the control parameters; 5) If the control target does not exceed the allowable range, keep the control parameters unchanged. The invention has high reliability and adaptability, can realize the power control of the power converter under the disturbance of the power grid, and has important practical significance for improving the operation reliability and controllability of the power converter.