Abstract: Provided in the present invention is a direct current power grid voltage control method, dividing control of a direct current power grid voltage into three processes, namely natural voltage regulation, first voltage regulation and second voltage regulation; the converter stations in the direct current power grid are divided into three types, namely power regulation converter stations, auxiliary voltage regulation converter stations, and voltage regulation converter stations, on the basis of whether the converter station has a voltage regulation capacity, the power regulation converter stations operating in a fixed power control mode, the voltage regulation converter stations operating in a fixed voltage control mode or an auxiliary voltage control mode, and the auxiliary voltage control converter stations operating in the auxiliary voltage control mode; all the converter stations in the direct current power grid participate in natural voltage regulation, the auxiliary voltage regulation converter stations and

Abstract: Provided is an on-line input and quit control method for a voltage-source converter unit. The method achieves the on-line input of a voltage-source converter unit by means of performing steps, such as charging control, deblocking transfer control and operation adjustment control, on a voltage-source converter to be input, and achieves the on-line quitting of the voltage-source converter unit by means of performing steps, such as direct-current voltage reduction control, bypass transfer control and converter blocking control, on a voltage-source converter to be quit. Correspondingly, provided is an on-line input and quit control device for a voltage-source converter unit, which can achieve the on-line steady input and quitting of a voltage-source converter in a series-type hybrid direct-current power transmission system or a series-type flexible direct-current power transmission system, without affecting the normal and stable operation of other already running converters.

Abstract: Disclosed in the present invention is a voltage and current control method for a direct-current transmission system. The method comprises: calculating a DC voltage reference value of a voltage source converter of a DC voltage control end, on the basis whether a direct-current voltage end of a direct-current pole of a direct-current transmission system substantially controls a direct-current voltage; using ½ of the calculated direct-current voltage reference value of the voltage source converter as a bridge arm voltage direct-current bias, calculating a difference between the direct-current voltage reference value of the voltage source converter and a measured direct-current voltage value, and inputting the difference into a direct-current voltage control outer loop of the voltage source converter to perform closed-loop control, so as to control the direct-current voltage or the direct current of the direct-current pole.

Abstract: A sub-module based hybrid converter is provided. By setting a half-controlled charging link of changing full bridge sub-modules from a blocked state to a half-blocked state one by one in a charging process, and raising the voltages of half bridge sub-modules to reach the starting point of a half bridge sub-module based self-powered supply in an uncontrolled stage of the half bridge sub-modules, the starting point of the sub-module based self-powered supply is increased, and the design difficulty of the sub-module based self- powered supply is reduced. The present invention also includes another charging method for a sub-module based hybrid converter.

Abstract: A chained multi-port grid-connected interface apparatus includes a commutation chain, at least one direct-current converter, and at least one direct-alternating converter. The commutation chain is formed by at least two sub-module units connected in series in the same direction, one end of the direct-current converter is connected to a direct-current end of the sub-module unit, and the other end is a direct-current interaction port of the chained multi-port grid-connected interface apparatus. A direct-current connection end of the direct-alternating converter is connected to the direct-current end of the sub-module unit, and an alternating-current connection end is an alternating-current interaction port of the chained multi-port grid-connected interface apparatus.

Abstract: A fault switch configuration and clearing method in a flexible DC converter station, the flexible DC converter station is configured with a grid side switch and a valve side phase-split switch in the converter station. When a fault occurs, a faulty phase and a non-faulty phase are detected and identified by means of differential protection or low voltage overcurrent. An alternating current zero crossing condition is created by means of firstly turn off the non-faulty phase valve side phase-split switch and the grid side switch, thereby cutting off the faulty phase, disconnecting the connection between a power supply and a fault point, and achieving the clearing for faults. The described fault-clearing method is simple and practical, highly reliable, and connection between the fault point and the power supply is quickly and effectively cut; converter station equipment is effectively protected, and further expansion of the fault is avoided.

Abstract: A method and apparatus for controlling a hybrid direct-current (DC) transmission system. The method comprises: adjusting the total number of inserted sub-modules of a modular multi-level converter and the polarity of an output level of the inserted sub-modules in real time, according to a DC voltage of a rectifier station at other end; or adjusting the total number of inserted sub-modules of a modular multi-level converter and the polarity of an output level of the inserted sub-modules in real time, according to the magnitude of a DC current or DC power; or adjusting the total number of inserted sub-modules of a modular multi-level converter and the polarity of an output level of the inserted sub-modules in real time, according to both the magnitude of the DC current and the DC voltage of the rectifier station at the other end. The method can effectively control the DC voltage and the direct current of a hybrid DC transmission system, avoiding the power transmitting breakdown.

Abstract: A method and apparatus for suppressing the impact of a compensator on line distance protection is provided, wherein the method comprises: obtaining a first current of a line connected to a compensator or series converters in the compensator, and a first voltage of a bus connected to the compensator or the line connected to the compensator; exiting the series converters and series transformers if the first current is greater than a preset current threshold and a duration is greater than a first preset time threshold; exiting the series converters and the series transformers if the first voltage is less than or equal to a preset voltage threshold and duration is greater than a second preset time threshold set the output voltage of the series converters to zero, and if a second current of an element corresponding to the first current meets conditions which the first current needs to meet; and otherwise, canceling the setting of the output voltage of the series converters to zero and obtaining a first current if

Abstract: A housing structure of a planar resistor is provided, wherein electrode extraction ends of the planar resistor are on the same side of the resistor. A housing structure body is made of an insulating material covering the surface of the resistor. An insulating structure having a groove opening facing toward or away from the resistor is provided around each electrode extraction end of the resistor. The insulating structure is configured to be a multi-tooth or multi-groove insulating structure.

Abstract: An apparatus and method for ensuring the reliability of a trip protection of an intelligent substation. The apparatus comprises a main CPU and an auxiliary CPU connected together, and a main FPGA and an auxiliary FPGA connected together. The main FPGA and the auxiliary FPGA are connected to a physical layer of a protection apparatus, and the main CPU and the auxiliary CPU are connected to a state monitoring data output end of a protected device. The main CPU sends a processing result to the main FPGA, the auxiliary CPU sends the processing result to the auxiliary FPGA, and the auxiliary FPGA synchronizes current information with the main FPGA after receiving information sent by the auxiliary CPU. When the main FPGA receives trip information, the main FPGA comparing the consistency of current trip information obtained from the main CPU with current trip information obtained from the auxiliary FPGA.

Abstract: An assembly method for a DC converter valve includes: assembling a top shielding case: lifting the top shielding case to a designated height via a lifting platform, and then fixedly connecting the top shielding case to lower ends of insulators, fixedly connecting upper ends of the insulators to a truss, the truss being located on the top of a valve hall; assembling valve layers: lifting the valve layers to designated locations in a sequence from top to bottom via the lifting platform; and assembling a bottom shielding case: lifting the bottom shielding case to a designated height via the lifting platform, connecting the bottom shielding case to a lowermost valve layer and suspending the bottom shielding case below the lowermost valve layer via suspension insulators. By means of the present invention, the operation is convenient, a small quantity of devices is used, and the security and reliability are high.

Abstract: The present invention discloses a charging method for a sub-module based hybrid converter. By setting a half-controlled charging link of changing full bridge sub-modules from a blocked state to a half-blocked state one by one in a charging process, and raising the voltages of half bridge sub-modules to reach the starting point of a half bridge sub-module based self-powered supply in an uncontrolled stage of the half bridge sub-modules, the starting point of the sub-module based self-powered supply is increased, and the design difficulty of the sub-module based self-powered supply is reduced. The present invention also discloses another charging method for a sub-module based hybrid converter. The above objective can also be achieved by setting a half-controlled charging link of changing the full bridge sub-modules from a blocked state to a bypassed state one by one in the charging process.

Abstract: An adaptive protection method for impedance of parallel capacitors comprises monitoring a terminal voltage and current of the capacitor; automatically calibrating the initial impedance of the capacitor when the capacitor is put into operation; calculating a real-time impedance of the capacitor during operation, dynamically updating the actual impedance of the capacitor periodically; comparing the real-time impedance of the capacitor with the actual impedance, updating the actual impedance if the relative value of the modulus of the real-time impedance change does not exceed the dynamic update limit threshold and the dynamic update reaches update period; generating an update failure alarm if the relative value of the modulus of the real-time impedance change exceeds the dynamic update limit threshold; generating a protection alarm if the relative value of the modulus of the real-time impedance change satisfies the protection alarm condition and the delay time is reached; and protecting the trip outlet if the r

Abstract: A novel reactive power overexcitation regulation technology for synchronous generator, comprises measuring a stator voltage, a stator current, an active power and a reactive power of the synchronous generator; calculating the allowable upper limit value of the reactive power of the generator according to the allowable stator current of stator heating, and calculating the allowable value of the reactive power of the minimum stator current of the generator according to the contact reactance between the generator and the grid; comparing the stator current with its allowable value, calculate the excess calorific value of the stator of the generator if the calculated actual stator current is larger than its allowable value, enter reactive power overexcitation limiting regulation mode if the excess calorific value of the generator reaches the upper limit of the allowable heating margin of the generator; and using the larger value between the allowable upper limit value of the reactive power and the allowable value

Abstract: A thyristor valve test system based on cooperation of logic functions of software, wherein the test system comprises: a thyristor valve (5) to be tested, a VBE (3) and a tester (4), and the VBE (3) has a dedicated test mode, the tester (4) provides three steps for each test item. The thyristor valve (5) to be tested and the VBE (3) are connected by optical fibers (1), and the thyristor valve (5) to be tested and the tester (4) are connected by cables (2), and there is no connection between the VBE (3) and the tester (4).

Abstract: A reconfigurable MMC sub-module unit and a control unit thereof are provided, the reconfigurable MMC sub-module unit is mainly formed by an MMC sub-module unit and a reconfigurable mechanism, wherein the reconfigurable mechanism is formed by switches, and the conversion of MMC sub-module unit topology is achieved through switching on and off the switches in the reconfigurable mechanism. According to the reconfigurable MMC sub-module unit and the control unit thereof, the rapid change of a topology structure for a converter can be achieved, which is suitable for the demand of the line connection of the medium-voltage power distribution network and variable topologies, and meets requirements of dynamic simulation experiment for different converter topologies in the dynamic simulation experiment, thereby reducing construction costs and duration, improving experiment efficiency, and having high flexibility and strong versatility.

Abstract: The present invention discloses a charging method for a sub-module based hybrid converter. By setting a half-controlled charging link of half-blocking all full bridge sub-modules in a charging process, and raising the voltages of half bridge sub-modules to reach the starting point of a half bridge sub-module based self-powered supply in an uncontrolled stage of the half bridge sub-modules, the starting point of the sub-module based self-powered supply is increased, and the design difficulty of the sub-module based self-powered supply is reduced. The present invention also discloses another charging method for a sub-module based hybrid converter. The above objective can also be achieved by setting a half-controlled charging link of bypassing all full bridge sub-modules in the charging process.

Abstract: A method for fault positioning and recovery of a voltage source converter includes following steps. Locking a converter station when it is detected that an alternating-current voltage contains a zero sequence voltage or a direct-current voltage contains an unbalanced voltage. Positioning a fault by continuing to detect the zero sequence voltage of an alternating-current side of the converter. Recovering operation of each station after the fault is positioned. The method for fault positioning and recovery is simple, practical, has high reliability, and can effectively detect the problems that each station contains a zero sequence voltage of an alternating-current side and cannot easily position a fault caused due to transmission of the zero sequence voltage of the alternating-current side to an opposite-side alternating-current system via a voltage source converter.

Abstract: Provided in the present invention is a direct current power grid voltage control method, dividing control of a direct current power grid voltage into three processes, namely natural voltage regulation, first voltage regulation and second voltage regulation; the converter stations in the direct current power grid are divided into three types, namely power regulation converter stations, auxiliary voltage regulation converter stations, and voltage regulation converter stations, on the basis of whether the converter station has a voltage regulation capacity, the power regulation converter stations operating in a fixed power control mode, the voltage regulation converter stations operating in a fixed voltage control mode or an auxiliary voltage control mode, and the auxiliary voltage control converter stations operating in the auxiliary voltage control mode; all the converter stations in the direct current power grid participate in natural voltage regulation, the auxiliary voltage regulation converter stations and

Abstract: A novel reactive power overexcitation regulation technology for synchronous generator, comprises measuring a stator voltage, a stator current, an active power and a reactive power of the synchronous generator; calculating the allowable upper limit value of the reactive power of the generator according to the allowable stator current of stator heating, and calculating the allowable value of the reactive power of the minimum stator current of the generator according to the contact reactance between the generator and the grid; comparing the stator current with its allowable value, calculate the excess calorific value of the stator of the generator if the calculated actual stator current is larger than its allowable value, enter reactive power overexcitation limiting regulation mode if the excess calorific value of the generator reaches the upper limit of the allowable heating margin of the generator; and using the larger value between the allowable upper limit value of the reactive power and the allowable value