Permanent magnet synchronous motor （PMSM）has the advantages of fast dynamic response，high power density，and high torque at low speed，but the temperature variation and complex working conditions will cause the variation of PMSM parameters， thus affect motor performance and reduce the output efficiency. To address the controller parameter mismatch problem caused by the change of motor parameters in the model predictive current control，firstly an adaptive linear （Adaline）neural network was used for the online identification of the parameters of the PMSM such as inductance，flux and resistance，and then the normalized least mean square （NLMS）algorithm was introduced to improve the Adaline neural network algorithm in order to improve the convergence speed and computational accuracy of the algorithm. In addition，the high-frequency current component of the model predictive control was utilized to calculate the PMSM rotor position and the parameters of rotor angle and speed were adopt to achieve sensorless control. The experimental results show that the improved NLMS-Adaline neural network is of practical value in terms of speed and accuracy compared with recursive RLS and traditional Adaline online identification，along with a nice adaptation to parameters mismatching.

Owing to the influence of wave fluctuation，the output power of ship photovoltaic（PV）power generation system is in the state of fluctuation，which significantly affects the quality of electricity and the reliability of power supply，and the sun-tracking algorithm of the land-based PV system fails to adapt to the operating conditions of ships. An optimal tilt angle predictive method of PV panels under the working conditions of marine vessels was proposed，which took into account the influence of wave fluctuation and sun position change on the output power of ship PV power generation system，analyzed the fluctuation characteristics of the output power curves under the same solar altitude angle，different solar radiation energy and temperature conditions during the rocking cycle of the ship，and predicted the optimal working angle of photovoltaic panels by using BP neural network to adjust the PV panel to improve the output power fluctuation and increase the output power. It is illustrated that the mean absolute percentage error （MAPE）of the proposed method is less than 0.6% and the root mean square error （RMSE）is less than 0.1，the reliability of the proposed method was verified.

Security is a critical concern that must be addressed in the context of the electric power metering internet of things （IoT）. In order to achieve complete isolation between data stored in the public cloud （external network）and data stored in the private cloud （internal network），while enabling unidirectional communication from the external network to the internal network，a non-electric communication method based on encrypted QR codes was proposed. The method involved the generation of colored QR codes containing metering inspection information on the external network side. Data from the external network was transmitted unidirectionally to the internal network via these colored QR codes，with no electrical connection between the internal and external networks. To enhance security，a color/information hybrid encryption method was employed. The original inspection information was encrypted using the SM4 algorithm to generate monochrome QR codes. Subsequently，the monochrome QR codes were further encrypted using different colors by DNA and chaos，leveraging the rich color gamut of the display monitor. Experimental results demonstrate 100% accuracy in encryption and decryption，encryption and decryption computational speeds of less than 0.058 7 s，and linearly increasing time consumption. This method exhibits high accuracy and speed，meeting the requirements of electric power metering IoT systems in terms of transmission rate，security and reliability.

In order to solve the problem that the electrical cabinet of the original production and injection system in the same well has a low intelligence level and cannot realize remote monitoring，diagnosis，restart and maintenance through the network，an intelligent control software for production and injection in the same well was developed based on the LabVIEW platform，and combined with the electrical control cabinet，wellhead sensors，valves and other equipment，a set of intelligent control system was designed to realize the intelligent monitoring of the same well production and injection system. It ensures the stable and continuous gas production of gas wells，improves the degree of automation，and reduces the maintenance cost.

In DC power grid，when serious metallic short circuit fault occurs in the DC side line of voltage source converter （VSC），the fault current has the characteristics of a fast rising speed and a large peak. The DC circuit breaker is used to isolate the fault，which greatly increases the requirements for the quick action and breaking capacity of the DC circuit breaker. Based on the VSC bipolar short circuit fault characteristics，a fault current limiting scheme with residual current operated protective device（RCD）current peak suppression circuit in series with the DC line was proposed. The current limiting circuit，which controlled the opening and closing of the thyristor，not only interrupted the discharge loop of the DC side capacitor to the fault point，but also effectively reduced the peak fault current and limited the fault steady state current to a given reference value.The PSCAD/EMTDC simulation platform was used to test the VSC bipolar short circuit fault and the proposed current limiting scheme，and the effectiveness of the proposed scheme was compared with that of the other two fault current limiting schemes，which verified the superiority of the proposed scheme based on energy transfer circuit.

Based on the parallel structure of high-power converter system，a high real-time and high synchronization optical-fiber communication scheme was proposed. The on-fly transmission ensures that the communication between the controllers has a low delay，and the clock synchronization algorithm compensates the time-difference between the master-controller and slave-controller，which ensure clock synchronization of all the controllers in the system to reduce circulation and its harm. When the system needs to run down or has a serious fault，the system could respond in time by changing the number of slave controllers in the optical-fiber communication network actively or passively，which provided flexible communication solutions for high power converter systems. The experimental results show that the proposed optical-fiber communication scheme is effective.

Taking the planar rotation mechanism as an example，a magnetic coupling wireless power transmission system was designed and studied from two perspectives：the spatial structure of the coils and the resonant compensation circuit. This system aimed to reduce the voltage fluctuations caused by significant changes in mutual inductance between the coils during rotation and ensure system stability. Regarding the spatial structure of the coils，four coils were fixed on a stationary plane at the transmitter end，while two coils were used at the receiver end and fixed on the plane of the rotation mechanism to ensure that they could induce a certain amount of current during rotation. For resonant circuit compensation，an LCC/S-type compensation network was adopted. The current at the transmitter end is only influenced by the compensating inductance and input voltage，further enhancing the coils' resistance to offset. This approach provides significant advantages in terms of power transmission and efficiency improvement. Finally，a simulation and experimental platform was established to validate the design. The experimental results demonstrated that using two receiver coils and the LCC/S topology resulted in improved output voltage，power，and efficiency while maintaining stability to a certain degree.

In order to study the operating characteristics of onboard power net of high-speed maglev train，an automated networking test system based on LabVIEW was developed on the basis of several independent onboard power net test systems. Through the comprehensive simulation of the external power supply of the train，the running speed of the train and the possible fault mode on the train，the ground combination test was realized after the networking of the onboard power net equipment with different power supply system and different design parameters.

Relay coil is an effective method to improve the performance of wireless power transmission. But the selection of relay coil position is usually based on experience. To elucidate the mechanism of the impact of relay coils on system performance，the port impedance differences between typical two-coil and relay-type coupling mechanisms were compared. The dynamic sweep analysis was used to summarize the influence of relative position on mutual inductance. Experiments was conducted. The impact of relative spatial position of relay coils on system performance was verified，as well as the correctness of theoretical and simulation analysis. The research on the position characteristics of relay coils has some reference significance for the optimization design of relay-type wireless power transmission.

The high proportion of renewable energy system is an inevitable choice to achieve the dual carbon target，but the uncertainty of wind and solar output will cause serious wind and light abandonment. With the deepening reform of the electricity market，the demand-side response has also attracted much attention. In view of the above problems，taken the wind-solar-storage industrial park as the research object，combined with the operation mechanism of Guangdong power spot market，a multi-time scale joint optimization operation method was proposed.In the day-ahead stage，considering the demand-side response，an economic dispatch model with the minimum daily operation cost of the park as the target was established，and the 24 hours power plan curve of the spot day-ahead market was obtained. In the real-time stage，the control strategy of using the hybrid energy storage system to stabilize the planned power deviation of the wind-solar-storage industrial park was proposed. The simulation results show that this method can improve the utilization rate of wind and solar energy and significantly improve the economic operation level of the park. On a typical sunny and windy day，the total cost of the park's day-ahead operation decreased by 37.12%，and the assessment power decreased by 93.5%. On the typical day of rainy days and less wind，the total cost of the park's day-ahead operation decreased by 10.1%，and the assessment power decreased by 99.9%. The qualified rate of the control index is significantly improved，and the planned power deviation is effectively improved.