Abstract: Systems, devices, and methods are described herein that facilitate using predictive-control based LVRT methods for grid-tied inverters.

Abstract: The present disclosure discloses a combined offshore wind power foundation with duct piles and a bucket, which comprises duct piles and a bucket foundation; the bucket foundation includes a steel bucket skirt, a bucket top cover, main beams, ring beam and a transition section. A top of the steel bucket skirt and the bucket top cover are integrally formed into a semi-closed structure. The bucket top cover is provided thereon with main beams uniformly arranged in a circumferential direction. The ring beam are arranged at an edge of the bucket top cover. Each duct pile includes a duct, a steel pile, duct supports and high-strength mortar, each main beam is provided at its outer side end with one of corresponding. The duct support is connected with the main beam and the ring beam, and integrated with the bucket top cover, the main beams and the ring beam.

Abstract: A relief valve structure (20) attached to a pump body (10) includes: a first discharge portion (31) for discharging oil when a discharge pressure is a first predetermined pressure; a second discharge portion (32) for discharging the oil when the discharge pressure reaches a second predetermined pressure higher than the first predetermined pressure; a third discharge portion (33) for discharging the oil when the discharge pressure exceeds the first predetermined pressure and reaches the second predetermined pressure or a pressure lower than the second predetermined pressure; and a pressure relief hole (34) for releasing the oil from an area around a valve spring (23). The second discharge portion, the first discharge portion, the third discharge portion, and the pressure release hole are provided in this order between an introduction portion (29) and a spring retaining member (24) when viewed from the introduction portion (29).

Abstract: A relief valve structure (20) attached to a pump body (10) includes: a first discharge portion (31) for discharging oil when a discharge pressure is a first predetermined pressure; a second discharge portion (32) for discharging the oil when the discharge pressure reaches a second predetermined pressure higher than the first predetermined pressure; a third discharge portion (33) for discharging the oil when the discharge pressure exceeds the first predetermined pressure and reaches the second predetermined pressure or a pressure lower than the second predetermined pressure; and a pressure relief hole (34) for releasing the oil from an area around a valve spring (23). The second discharge portion, the first discharge portion, the third discharge portion, and the pressure release hole are provided in this order between an introduction portion (29) and a spring retaining member (24) when viewed from the introduction portion (29).