Research On The Force Ripple And Temperature Rise Of A Double-sided Permanent Magnet Linear Generator

Non-renewable energy consumption makes the traditional energy used to power generation such as coal, oil, gas be exhausted gradually. This makes people pay attention to new energy power generation technology. Wave energy power generation is green and it can supply marine instruments power directly. Its large scale using can solve people’s demand for electricity. And it is one of the new energy form of international concern. Permanent magnet linear motor applied in wave power generation device can avoid the inversion mechanism which convert linear motion to rotary motion. This will improve the efficiency of the whole system. So the permanent magnet linear motor gradually replaces the traditional rotary motor in the wave power generation device. It becomes the focus of researches. This paper studies on a double-sided tubular permanent magnet linear generator(DSTPMLG) which has high power density, and completes the optimization of the temperature rise and force ripple of the generator. Following are the main contents:1.The structure and the electric-generation principle of the DSTPMLG were introduced. The magnetic field analytical model of the DSTPMLG was built with field calculation method.2.The electromagnetism model of the DSTPMLG was built using the finite element method(FEM). The steady magnetic field model and the transient magnetic field model were built respectively. And the no-load condition and rated load condition of the DSTPMLG were solved respectively. The FEM results and the analytical calculation results of the magnetic field were compared. Both of them can fit well. This validated the analytical calculation results.3.The temperature field of the DSTPMLG was analyzed using the FEM. The phenomenon that the internal temperature is far higher than the external temperature was founded. The causes of this phenomenon were analyzed. An improved inner construction and the best ratio of external current to internal current were proposed to keep the internal temperature and the externaltemperature equal. And then the overall temperature rise performance was improved.4.The force ripple was optimized based on the new DSTPMLG. The causes of the force ripple were analyzed. The force ripple was decreased by reducing the end force and slot force. At last, the optimal design principles that can be used for waking the the force ripple of the DSTPMLG were proposed.