Abstract: Disclosed are a silicon nitride ceramic sintered body and preparation method thereof. The silicon nitride ceramic sintered body includes a sintered bulk and a hard surface layer having a thickness of 10-1000 ?m, formed on a surface of the sintered bulk, wherein the sintered bulk comprises a first silicon nitride crystalline phase and a first grain boundary phase; the hard surface layer comprises a second silicon nitride crystalline phase and a second grain boundary phase; the first grain boundary phase comprises a metal tungsten phase being tungsten elementary substance and/or a tungsten alloy; the second grain boundary phase comprises tungsten carbide particles; tungsten element in the metal tungsten phase accounts for 80-100 wt % of total tungsten element in the first grain boundary phase; and tungsten element in the tungsten carbide particles accounts for 60-100 wt % of total tungsten element in the second grain boundary phase.

Abstract: A photovoltaic power plant and a secondary frequency modulation control method therefor are disclosed. The photovoltaic power plant includes a photovoltaic power station and an active power control system, wherein the photovoltaic power station includes a photovoltaic array and a photovoltaic inverter, the photovoltaic inverter being used for converting direct-current electric energy generated by the photovoltaic array into alternating-current electric energy; and the active power control system is used for performing power allocation on the photovoltaic inverter based on a power control AGC instruction value when running data of the photovoltaic power plant meets a pre-set secondary frequency modulation condition, and adjusting an active power output from the photovoltaic inverter based on an AGC instruction value of the photovoltaic inverter subjected to power allocation. The photovoltaic power station can improve the accuracy of power control and the stability of a power system.

Abstract: A test and control apparatus, system and method for a wind farm, are provided. The test and control apparatus includes a first communication interface, a second communication interface, and a processor card. The processor card receives, via the first communication interface, a frequency regulation instruction issued by the grid scheduling server, receives operation information of the wind power generation unit via the second communication interface, and calculates, based on the operation information of the wind power generation unit, a first frequency regulation capability of the wind power generation unit performing a frequency regulation without using the first energy storage battery. The processor card sends the frequency regulation instruction to the wind power generation unit without using the first energy storage battery, in a case that the first frequency regulation capability of the wind power generation unit satisfies a requirement of the frequency regulation instruction.

Abstract: A method and a control device for adjusting active power of a wind farm, and a controller of a wind farm are provided. The method includes: acquiring an active power increment to be adjusted in the wind farm; determining an active power adjustable amount of the wind farm based on active power adjustable amounts of wind turbines in the wind farm; and determining an active power adjustment amount of each of the wind turbines based on the active power increment to be adjusted in the wind farm and the active power adjustable amount of the wind farm, to adjust active power of each of the wind turbines.

Abstract: The present invention provides a power control method, device and system for a wind power station. The power control method comprises: obtaining running state data of the wind power station and a grid connection point in real time; determining whether the state of the grid connection point meets conditions of secondary frequency modulation according to the running state data; if it is determined that the state of the grid connection point meets the conditions of secondary frequency modulation, determining a limited power instruction value according to a pre-obtained theoretical power value of the wind power station, a given value of automatic power generation control, and a standby active power value reserved for primary frequency modulation; and generating and sending an instruction used for controlling the active power of the wind generating set of the wind power station according to the limited power instruction value.

Abstract: Disclosed are a photovoltaic power plant and a primary frequency modulation control method therefor. The photovoltaic power plant comprises a photovoltaic power plant and an active power control system. The photovoltaic power plant comprises a photovoltaic array and a photovoltaic inverter, the photovoltaic inverter converting direct current electric energy generated by the photovoltaic array into alternating current electric energy. The active power control system is used for determining the variable quantity of active power of a single machine according to an operating state of the photovoltaic inverter when frequency values of grid connection points of the photovoltaic power plant meet a pre-set primary frequency modulation triggering condition, and regulating the active power output by the photovoltaic inverter. According to the disclosed photovoltaic power, the response speed and accuracy of primary frequency modulation of a generator set can be improved.

Abstract: A reactive power control method, a reactive power control device, and a reactive power control system are provided. The device includes: a communication interface, configured to receive a reactive power requirement command; an input interface, configured to acquire an electrical quantity parameter of a preset control point; a strategy calculation module, configured to calculate a target reactive power value meeting the reactive power requirement command based on the electrical quantity parameter, and allocate reactive power to be provided by a regulatable reactive device based on the target reactive power value; and an output interface, configured to send a command for providing the allocated reactive power to the regulatable reactive device.

Abstract: A test and control apparatus, system and method for a wind farm, are provided. The test and control apparatus includes a first communication interface, a second communication interface, and a processor card. The processor card receives, via the first communication interface, a frequency modulation instruction issued by the grid scheduling server, receives operation information of the wind power generation unit via the second communication interface, and calculates, based on the operation information of the wind power generation unit, a first frequency modulation capability of the wind power generation unit performing a frequency modulation without using the first energy storage battery. The processor card sends the frequency modulation instruction to the wind power generation unit without using the first energy storage battery, in a case that the first frequency modulation capability of the wind power generation unit satisfies a requirement of the frequency modulation instruction.

Abstract: A reactive power control method, a reactive power control device, and a reactive power control system are provided. The device includes: a communication interface, configured to receive a reactive power requirement command; an input interface, configured to acquire an electrical quantity parameter of a preset control point; a strategy calculation module, configured to calculate a target reactive power value meeting the reactive power requirement command based on the electrical quantity parameter, and allocate reactive power to be provided by a regulatable reactive device based on the target reactive power value; and an output interface, configured to send a command for providing the allocated reactive power to the regulatable reactive device.

Abstract: The present invention provides a power control method, device and system for a wind power station. The power control method comprises: obtaining running state data of the wind power station and a grid connection point in real time; determining whether the state of the grid connection point meets conditions of secondary frequency modulation according to the running state data; if it is determined that the state of the grid connection point meets the conditions of secondary frequency modulation, determining a limited power instruction value according to a pre-obtained theoretical power value of the wind power station, a given value of automatic power generation control, and a standby active power value reserved for primary frequency modulation; and generating and sending an instruction used for controlling the active power of the wind generating set of the wind power station according to the limited power instruction value.

Abstract: A photovoltaic power plant and a secondary frequency modulation control method therefor are disclosed. The photovoltaic power plant includes a photovoltaic power station and an active power control system, wherein the photovoltaic power station includes a photovoltaic array and a photovoltaic inverter, the photovoltaic inverter being used for converting direct-current electric energy generated by the photovoltaic array into alternating-current electric energy; and the active power control system is used for performing power allocation on the photovoltaic inverter based on a power control AGC instruction value when running data of the photovoltaic power plant meets a pre-set secondary frequency modulation condition, and adjusting an active power output from the photovoltaic inverter based on an AGC instruction value of the photovoltaic inverter subjected to power allocation. The photovoltaic power station can improve the accuracy of power control and the stability of a power system.

Abstract: Disclosed are a photovoltaic power plant and a primary frequency modulation control method therefor. The photovoltaic power plant comprises a photovoltaic power plant and an active power control system. The photovoltaic power plant comprises a photovoltaic array and a photovoltaic inverter, the photovoltaic inverter converting direct current electric energy generated by the photovoltaic array into alternating current electric energy. The active power control system is used for determining the variable quantity of active power of a single machine according to an operating state of the photovoltaic inverter when frequency values of grid connection points of the photovoltaic power plant meet a pre-set primary frequency modulation triggering condition, and regulating the active power output by the photovoltaic inverter. According to the disclosed photovoltaic power, the response speed and accuracy of primary frequency modulation of a generator set can be improved.

Abstract: Several agents capable of inducing vascular responses akin to those observed in inflammatory processes enhance the accumulation of nanoparticles in tumors. Exemplary vascular-active agents include a bacterium, a pro-inflammatory cytokine, and microtubule-destabilizing drugs. Such agents can increase the tumor to blood ratio of radioactivity by more than 20-fold compared to nanoparticles alone. Moreover, vascular-active agents dramatically improved the therapeutic effect of nanoparticles containing radioactive isotopes or chemotherapeutic agents.