Seigniorage Channel and Monetary Effectiveness in Flexible Price Economy

Replacing government lump-sum transfers in the household budget by the seigniorage channel in a modified RBC economy, this paper finds that the monetary shocks can impact the real economy effectively in the Neoclassical flexible price condition. The mechanism of the effectiveness is the resource reallocation triggered by monetary shocks. There are three outstanding characteristics of the seigniorage channeled monetary economy—integrality, interactive pricing, and Pareto optimality of the unique equilibrium—all of which are found to be incompatible with the existing dynamic general equilibrium monetary economics. Many vexing issues in macroeconomics are clarified through the lens of the seigniorage channeled monetary economy, including the price puzzle, missing of the liquidity effect, cause of the hump in the impulse-response curves, nonneutrality of growth rate of money and inflation, origin of the money market interest rate, choosing of reactive monetary policy rule, and negative movement of hours under a positive technology shock. The simulation shows that the seigniorage channeled monetary economy matches the empirical results in the literature well

Accuracy improvement on fatigue test of megawatt wind turbine blades by adaptive fuzzy control

A single-point fatigue loading system of wind turbine blade driven by an unbalanced shaft was designed. To determine whether the vibrating performance of the loading system satisfied the fatigue test demanding, the blade was driven by different frequency under open-loop control mode in on-site flapwise fatigue test. The results showed that the more the driven frequency close to the blade’s natural frequency, the more the amplitude of the blade increase. In resonance mode, the amplitude of the blade can reach the maximum value certainly. However, the peak values of the vibration have some fluctuation, which will influence the accuracy of fatigue test. To solve the unstable problem of blade’s amplitude, the amplitude of blade’s loading point obtained by laser range meter was taken as the control index, the deviation of the amplitude and its variation tendency were taken as the input and the loading frequency as the output, then an adaptive fuzzy control system based on multistage network was built to realize blade’s constant amplitude vibrating. The on-site test showed the adaptive fuzzy control algorithm put forward in this paper could maintain the error of the peak value of vibration less than 5 mm, which satisfied the fatigue test requirement

Coupling mechanism of dual-excitation fatigue loading system of wind turbine blades

A new dual-excitation fatigue loading system of wind turbine blades was designed in this paper. However, the two excitations and blade constituted a complicated non-liner energy transferring system in which the vibration coupling effect would influence the sequent accurate control of fatigue test. To study the mechanism of the coupling system mentioned above, the electromechanical coupling mathematical model was established by simplifying the loading system rationally and the factors affecting the vibration coupling were obtained accordingly. Then the simulation model of the system was built in Matlab/Simulink environment to mainly analyze the basic influence laws of the motor speed and the initial phase difference of two excitations. Finally, a small dual-excitation fatigue loading system was established to verify the correctness of the mathematical and simulation model. It could be concluded that the results of on-site test were consistent with the results of simulation

Optimal Operation of an Integrated Electricity-heat Energy System Considering Flexible Resources Dispatch for Renewable Integration

Large fluctuations may occur on the energy supply and the load sides when large-scale renewable energies are integrated, leading to great challenges in power systems. The renewable power curtailment is especially numerous in the integrated electricity-heat energy system (IEHES) on account of electricity-heat coupling. The flexible resources (FRs) on both the energy supply and load sides are introduced into the optimal dispatch of the IEHES and further modeled to alleviate the renewable fluctuations in this paper. On the energy supply side, three kinds of FRs based on electricity-heat coordination are modeled and discussed. On the load side, the shiftable electricity demand resource is characterized. On this basis, the solution for FRs participating in IEHES dispatch is given, with goals of maximizing the renewable penetration ratio and lowering operation costs. Two scenarios are performed, and the results indicate that the proposed optimal dispatch strategy can effectively reduce the renewable energy curtailment and improve the flexibility of the IEHES. The contribution degrees of different FRs for renewable integration are also explored