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Abstract: A scheme of Simulation Traction Load (STL) with regenerative braking based on back-to-back dual PWM converters is proposed in this paper. The main function of AC/DC section is simulating traction load with specified characteristic employing current hysteresis control methods. Under the control of the current inner loop and voltage outer loop, the DC/AC section can feed the energy from DC/AC section back to power system. The feed-back energy can be supplied to other customers. It is proved that the proposed scheme simulates measured traction load well when measured load is considered as given load. [Copyright &y& Elsevier]

• Sr 3 In 1.76 Sm 0.04 Eu 0.20 WO 9 has high quantum efficiency, up to 69.42%. • Sr 3 In 1.76 Sm 0.04 Eu 0.20 WO 9 has excellent thermal stability, 73% at 423 K. • The packaged WLED has an excellent color rendering index Ra of 96. A series of Sr 3 In 2 WO 9 : x Sm3+ (x = 0.02, 0.03, 0.04, 0.05, and 0.06) and Sr 3 In 2 WO 9 : 0.04Sm3+, y Eu3+ (y = 0.05, 0.10, 0.15, 0.20, 0.25, 0.30, and 0.35) phosphors were synthesized by solid-state reaction method. Then the microstructure and optical properties of samples were tested by the corresponding means. The results show that the optimal doping concentration of single-doped Sm3+ phosphor is × = 0.04 and the performance of Sm3+/Eu3+ co-doped phosphors has been improved. The Sm3+ /Eu3+ co-doped phosphors exhibit characteristic emission of Sm3+ and Eu3+ under the excitation of 407 nm. The direct energy transfer mechanism between Sm3+ and Eu3+ originates from the dipole-quadrupole interaction. When y = 0.20, the energy transfer efficiency reaches 62.69%. The quantum yield of Sr 3 In 1.76 Sm 0.04 Eu 0.20 WO 9 is as high as 69.42%, which possesses excellent thermal stability, and the relative luminescence intensity reaches 73% at 423 K, while the thermal quenching activation energy Δ E is 0.280 eV. At the same time, after the Sm3+/Eu3+ co-doping, the chromaticity coordinates shifted from (0.5661, 0.4282) for mono-doped Sm3+ to (0.6176, 0.3787). The correlated color temperature of the packaged WLED is calculated to be 5591 K, and the color rendering index R a is 96. These results show that Sr 3 In 2 WO 9 :Sm3+, Eu3+ could be one of the potential candidates for white light-emitting LEDs under n-UV excitation. [ABSTRACT FROM AUTHOR]