53results about How to "Improve operational safety and stability" patented technology

The invention relates to a technical field of power grid generation control, in particular to provide an intelligent quantization weighted hydroelectric generating set automatic generation control system and arithmetic which comprises four functional modules: an electrical system zone control deviation calculation module, an intelligent quantization weighted automatic generation control module, a hydroelectric generating set subnet unbalancedness optimal operation output allocation module and a parameter self-adjusting optimal computation module. The intelligent quantization weighted hydroelectric generating set automatic generation control system and arithmetic is capable of quickly compensating random wavy load and the disturbance which the power imposes on line frequency and power balance, improving mains supply power quality, increasing the ability that the power grid absorbs wind power to generate electricity and improving the stability of security of operation of the electrical system.

The invention discloses an AC / DC decoupling control method of a modular multi-level converter. The method comprises the steps as follows: DC control is added to current inner loop control and comprises positive DC control and negative DC control, so that an output of AC control, an output of positive DC control and an output of negative DC control are taken as main components of output voltage reference values of various phase bridge arms of an MMC; and control on the main components of the output voltage reference values of various phase bridge arms of the MMC can be achieved by controlling the reference values and the outputs of the AC control, the positive DC control and the negative DC control, thereby preventing the converter from being locked due to overcurrent of the bridge arms in a DC failure. The invention further discloses an application of the method in the flexible DC power transmission system. According to the method disclosed by the invention, the condition that AC and DC are maintained within a safety range can be ensured, so that DC fault ride-through of the overhead flexible DC power transmission system is achieved.

The invention relates to the technical field of elevator manufacturing, in particular to a traction machine brake. The traction machine brake comprises a brake disc. A left brake pad and a right brake pad are arranged on the two sides of the left surface and the right surface of the brake disc respectively. The side, backing on to the brake disc, of the left brake pad is fixed to an armature plate. The side, backing on to the brake disc, of the right brake pad is fixed to an iron core plate right opposite to the armature plate. A connecting part is fixed to the side, close to the brake disc, of the armature plate and located above the brake disc, a connecting part is fixed to the side, close to the brake disc, of the iron core plate and located above the brake disc, and the two connecting parts can be crossed in the left-and-right direction. The connecting part of the armature plate and the connecting part of the iron core plate form a combined connecting part after being crossed and are connected in series through a connecting shaft rod arranged in the front-and-back direction, and the part, in front of the armature plate and the iron core plate, of the connecting shaft rod and the part, at back of the armature plate and the iron core plate, of the connecting shaft rod are connected to a brake installation base. The part, above the connecting shaft rod, of the iron core plate is provided with an electrified coil and a brake spring used for abutting against the armature plate. The traction machine brake is high in safety and stability, small in loss and low in noise and cost.

The invention provides a secondary air online measuring method for a turbulent burner, and the secondary air online measuring method is used for measuring the air speed in a secondary air duct of theturbulent burner. The measuring method comprises the following steps of selecting three measuring radiuses in the secondary air duct, wherein three circumferences taking the central point of the secondary air duct as the center of a circle by the three measuring radiuses, and the three circumferences are successively an inside circumference, a middle circumference and an outside circumference; anddividing the radial cross section of the secondary air duct into four annular regions by the three circumferences, wherein the radiuses of the three circumferences are successively r1, r2 and r3. Themethod provided by the invention can measure the blast capacities of secondary air hoses truly and effectively, provides a good basis for optimizing air distribution, optimizes the air distribution mode, reduces the electric consumption of a fan, reduces the station service power consumption rate, and improves the economical efficiency of a boiler.

The invention provides a turbulent burner secondary air on-line measuring system. The turbulent burner secondary air on-line measuring system comprises three sets of primary measuring elements which are radially distributed in three circumferences of radial sections of secondary air ducts. The three circumferences use the center points of the secondary air ducts as a center of a circle, and the three circumferences are sequentially the inner circumference, the middle circumference and the outer circumference. The radiuses of the three circumferences are sequentially r1, r2 and r3, and the radiuses are in units of meters. The radius of a first inner wall is rh, and the unit is meter; the radius of a second inner wall is re, and the unit is meter; and r1 is greater than rh, and r3 is less than re. The turbulent burner secondary air on-line measuring system truly and effectively measures the air volume of the secondary air ducts, provides a good foundation for optimizing air distribution,optimizes the air distribution mode to save power consumption of a fan, reduces the power consumption rate of a plant, and improves the economy of a boiler.

The invention provides a rotor structure of a permanent magnet motor, which can balance the axial temperature distribution of the permanent magnets, including a rotor core, a plurality of permanent magnets and eddy current rings; a plurality of permanent magnets and eddy current rings are embedded in the rotor core; The iron core extends axially and is arranged around the axis of the rotor iron core. The section of each permanent magnet is V-shaped; the outer surface of each permanent magnet is fitted with an eddy current ring, and the eddy current ring is located in the axial middle of the permanent magnet. The rotor structure provided by the present invention reduces the eddy current loss where the permanent magnet is wrapped by the eddy current ring by putting the eddy current ring on the axial center of the permanent magnet, thereby balancing the axial temperature distribution of the permanent magnet and reducing thermal stress. Problems with permanent magnet motor failure caused by balance. At the same time, the eddy current ring can reduce the maximum temperature of the permanent magnet, avoid the problem of partial demagnetization of the permanent magnet caused by local high temperature, and improve the safety and stability of the permanent magnet motor.

The invention discloses a safety control method and system for suppressing continuous commutation failure of a DC system, including a DC safety and stability control master station, a rectification and commutation control subsystem, and an inverter side state detection subsystem. Based on the commutation failure mechanism, through The number of commutation failures in the DC system and the commutation bus voltage on the inverter side are detected, and the DC power is rapidly reduced, thereby realizing the suppression of continuous DC commutation failures. The present invention can still reduce the risk of continuous commutation failure in the weak AC state of the receiving end power grid, can effectively prevent the continuous commutation failure of the DC system, and improve the safety and stability of the AC-DC hybrid system.

The invention discloses a power transmission line grounding distance protection III segment protection method. The method is characterized in that grounding fault phase voltage, grounding fault phase current, grounding fault phase negative sequence current, and zero sequence current of a power transmission line protection installation part can be measured; a grounding arc voltage phase can be calculated by using the phase of the grounding fault phase negative sequence current, and a grounding arc voltage amplitude of a power transmission line grounding fault point can be calculated, and a voltage amplitude variable quantity corresponding to a power transmission line grounding fault front / rear grounding fault point can be calculated, and then the grounding distance protection III segment protection criterion can be formed by using the voltage amplitude variable quantity corresponding the grounding fault point and the power transmission line rated phase voltage amplitude. The power transmission line grounding distance protection III segment protection criterion can be formed by using the grounding arc voltage amplitude characteristic of the power transmission line grounding fault point, and in principle, the influence of the additional impedance caused by the transition resistance on the grounding distance protection III segment protection motion performance can be eliminated, and then the capability of tolerating the strong transition resistance and the strong load current influence can be provided, and therefore the power transmission line grounding distance protection III segment protection correct motion can be guaranteed, the power grid flow big transfer caused by the back-up distance protection motion can be effectively prevented, and the safety and stability of the operation of the power grid can be enhanced.

The invention provides a generator neutral point displacement voltage limiting method, comprising the following steps: after the generator voltage circuit is installed, measure the generator three-phase stator circuit voltage and the current neutral point displacement voltage in real time; The difference between the maximum value and the minimum value among the three-phase stator circuit capacitances determines the capacitance that needs to be supplemented by the three-phase stator circuit; according to the determined supplementary capacitance of the three-phase stator circuit and the above-mentioned capacitance parameter setting requirements, the capacitor type is selected; clear After the capacitor, install the capacitor at the designated position; after the installation, measure the neutral point displacement voltage of the compensated three-phase stator circuit capacitance of the generator in real time to check whether the requirements are met; if the requirements are not met, repeat the above steps until Meet owner or standard requirements. The invention effectively suppresses the neutral point displacement voltage of the generator.