CN-121689068-B - Static SVG equipment suitable for heavy-duty locomotive load

CN121689068BCN 121689068 BCN121689068 BCN 121689068BCN-121689068-B

Abstract

The invention provides static SVG equipment suitable for heavy-load locomotive loads, which relates to the field of railway power supply and comprises a three-phase MMC converter, wherein each phase of the three-phase MMC converter comprises a three-phase bridge arm, each phase of the three-phase MMC converter consists of an upper bridge arm and a lower bridge arm, each upper bridge arm comprises a plurality of cascaded half-bridge sub-models, each lower bridge arm comprises a plurality of cascaded half-bridge sub-models, wherein an energy storage element of each half-bridge sub-module at least comprises a super capacitor, the static SVG equipment further comprises a voltage balancing module, a grid-structured voltage source control module and a grid-structured voltage source control module, wherein the voltage balancing module is used for determining the number of half-bridge sub-modules which are input in real time for each phase of the upper bridge arm and the lower bridge arm, and determining the half-bridge sub-modules which are input in real time for each phase of the upper bridge arm and the lower bridge arm based on the number of the half-bridge sub-modules which are input in real time for each phase of the upper bridge arm and the lower bridge arm, and the grid-structured voltage source control module is used for active control, reactive control and virtual impedance control.

Inventors

LUO ZHENPENG
LI DONGZE
XU GUANGQING
YANG BAOFENG
QI YONGSHENG
LIU GUANGCHEN

Assignees

内蒙古工业大学

Dates

Publication Date: 20260508
Application Date: 20260210

Claims (7)

1. The static SVG equipment suitable for heavy-duty locomotive load is characterized by comprising a three-phase MMC converter, wherein each phase of the three-phase MMC converter comprises a three-phase bridge arm, each phase of bridge arm consists of an upper bridge arm and a lower bridge arm, the upper bridge arm comprises a plurality of cascaded half-bridge sub-models, the lower bridge arm comprises a plurality of cascaded half-bridge sub-modules, and an energy storage element of each half-bridge sub-module at least comprises a super capacitor; Further comprises: the voltage balancing module is used for determining the number of the half-bridge sub-modules of the upper bridge arm and the lower bridge arm of each phase of bridge arm which are input in real time, and determining the half-bridge sub-modules of the upper bridge arm and the lower bridge arm of each phase of bridge arm which are input in real time based on the number of the half-bridge sub-modules of the upper bridge arm and the lower bridge arm of each phase of bridge arm which are input in real time; the network-structured voltage source control module is used for performing active control, reactive control and virtual impedance control; The voltage balancing module is further configured to: adjustment based on voltage deviation amplitude of each half-bridge sub-module included in bridge arm Is a value of (2); Adjusting based on the load power, the rate of change of the bridge arm current and the voltage fluctuation rate of each half-bridge sub-module included in the bridge arm And (3) with Is a value of (2); the comprehensive ordering index of the half-bridge submodule is calculated based on the following formula: , Wherein, the Is the comprehensive sequencing index of the ith half-bridge submodule, 、 And As the weight of the material to be weighed, , For the port voltage of the ith half-bridge sub-module, Is the current direction sign of the bridge arm where the ith half-bridge submodule is positioned, Is the remaining energy state of the super capacitor of the ith half-bridge sub-module, The voltage change rate of the super capacitor of the ith half-bridge sub-module; and determining the input half-bridge sub-modules of the upper bridge arm in real time and the input or cutting order of the half-bridge sub-modules included in the upper bridge arm based on the comprehensive sequencing index of each half-bridge sub-module.
2. A stationary SVG plant adapted for heavy locomotive loads according to claim 1, wherein said energy storage element comprises a super capacitor and a thin film capacitor connected in parallel.
3. A stationary SVG plant adapted for heavy locomotive loading according to claim 1 or 2, wherein said voltage equalization module is further adapted to: And determining the number of the half-bridge sub-modules input in real time of the upper bridge arm and the lower bridge arm of each phase based on the direct-current bus voltage, the rated voltage of the half-bridge sub-modules, the alternating-current side reference phase voltage of each phase and the instruction signal of each phase circulation.
4. A stationary SVG plant adapted for heavy-duty locomotive loads according to claim 3, wherein said voltage equalization module is further adapted to determine the number of half-bridge sub-modules of the upper and lower legs of each phase leg that are put into real time based on the following formula: ; ; ; ; ; ; Wherein N AP is the number of half-bridge sub-modules of the upper bridge arm of the a-phase bridge arm, V DC is the dc bus voltage, V 1 is the rated voltage of the half-bridge sub-modules, V A is the ac side reference phase voltage of the a-phase, HL A is the ac side reference phase voltage of the C-phase, N AL is the number of half-bridge sub-modules of the lower bridge arm of the a-phase bridge arm, N BP is the number of half-bridge sub-modules of the upper bridge arm of the B-phase bridge arm, V B is the ac side reference phase voltage of the B-phase, H LB is the command signal of the B-phase loop, N BL is the number of half-bridge sub-modules of the lower bridge arm of the B-phase bridge arm, N CP is the ac side reference phase voltage of the C-phase, H LC is the command signal of the C-phase loop, and N CL is the number of half-bridge sub-modules of the lower bridge arm of the C-phase bridge arm.
5. The stationary SVG plant adapted for heavy locomotive loads of claim 4, wherein said voltage equalization module is further adapted to: For the upper bridge arm of each phase of bridge arm, when the half-bridge sub-module of the upper bridge arm which is put into real time is more than 0 and less than the number of the half-bridge sub-modules included in the upper bridge arm, determining the half-bridge sub-modules of the upper bridge arm which are put into real time based on the direction of the bridge arm current and the state of the super capacitor of each half-bridge sub-module included in the upper bridge arm; For the lower bridge arm of each phase of bridge arm, when the half-bridge sub-module of the lower bridge arm which is input in real time is larger than 0 and smaller than the number of the half-bridge sub-modules included in the lower bridge arm, determining the half-bridge sub-modules of the lower bridge arm which are input in real time based on the direction of the bridge arm current and the energy state and the stress state of the super capacitor of each half-bridge sub-module included in the lower bridge arm.
6. A stationary SVG plant adapted for heavy locomotive loading according to claim 1 or 2, wherein said grid-formation voltage source control module is further adapted to: dynamically adjusting a virtual moment of inertia coefficient based on the energy of the super capacitor; And performing active control based on the virtual rotation inertia coefficient.
7. The stationary SVG plant adapted for heavy locomotive loads of claim 6, wherein said grid-tied voltage source control module is further adapted to: virtual impedance control is performed based on a frequency segmentation adaptive algorithm.

Description

Static SVG equipment suitable for heavy-duty locomotive load Technical Field The invention relates to the field of railway power supply, in particular to static SVG equipment suitable for heavy locomotive load. Background In the current energy transformation and traffic electrification development surge, the novel power system has a plurality of challenges. On one hand, renewable energy sources are connected into a power grid in a large scale and high proportion, the inherent intermittence and fluctuation of the renewable energy sources increase the power balance difficulty of the power grid, and on the other hand, the grid connection of high-power impact loads such as heavy haul railways and the like brings strong power impact to the power grid. The two work together to cause a series of problems of three-phase unbalance, phase flicker, short-time frequency/voltage dip and the like of the power grid, and the stable operation and the electric energy quality of the power grid are seriously affected. In the prior art, the rotary synchronous camera is a key device for guaranteeing the stability of a power grid and providing instantaneous energy support. However, with the continuous increase of the requirements of the new power system for response speed and adjustment capability, the existing rotary synchronous regulator gradually exposes obvious defects. The construction and operation costs are high, the overall economic burden of the power system is increased, the response speed is slow when the power demand of rapid change is faced, the sufficient energy support is difficult to provide in a short time, and the urgent demand of the novel power system on the instantaneous energy support cannot be fully met. Accordingly, there is a need to provide a stationary SVG apparatus adapted for heavy locomotive loads for adapting to heavy locomotive loads and improving the stability of power system operation. Disclosure of Invention The invention provides static SVG equipment suitable for heavy-load locomotive loads, which comprises a three-phase MMC converter, a voltage balancing module, a network-structured voltage source control module and a virtual impedance control module, wherein each three-phase MMC converter comprises a three-phase bridge arm, each phase bridge arm consists of an upper bridge arm and a lower bridge arm, each upper bridge arm comprises a plurality of cascaded half-bridge sub-models, each lower bridge arm comprises a plurality of cascaded half-bridge sub-modules, an energy storage element of each half-bridge sub-module at least comprises a super capacitor, the voltage balancing module is used for determining the number of half-bridge sub-modules which are input in real time to each upper bridge arm and each lower bridge arm of each phase bridge arm, and the network-structured voltage source control module is used for carrying out active control, reactive control and virtual impedance control on the number of the half-bridge sub-modules which are input in real time to each upper bridge arm and each lower bridge arm of each phase bridge arm. Further, the energy storage element comprises a super capacitor and a thin film capacitor which are connected in parallel. The voltage balancing module is further used for determining the number of the half-bridge sub-modules which are input in real time for the upper bridge arm and the lower bridge arm of each phase based on the direct-current side voltage value, the nominal voltage value of the energy storage element of the half-bridge sub-module, the reference voltage of each phase and the compensation quantity of each phase. Further, the voltage balancing module is further configured to determine the number of half-bridge sub-modules that are input in real time to the upper bridge arm and the lower bridge arm of each phase bridge arm based on the following formula: NAP=VDC/(2*V1)-round((VA+HLA)/V1); NAL=VDC/(2*V1)+round((VA-HLA)/V1); NBP=VDC/(2*V1)-round((VB+HLB)/V1); NBL=VDC/(2*V1)+round((VB-HLB)/V1); NCP=VDC/(2*V1)-round((VC+HLC)/V1); NCL=VDC/(2*V1)+round((VC-HLC)/V1); Wherein N AP is the number of half-bridge sub-modules of the upper bridge arm of the a-phase bridge arm, V DC is the dc bus voltage, V 1 is the rated voltage of the half-bridge sub-modules, V A is the ac side reference phase voltage of the a-phase, HL A is the ac side reference phase voltage of the C-phase, N AL is the number of half-bridge sub-modules of the lower bridge arm of the a-phase bridge arm, N BP is the number of half-bridge sub-modules of the upper bridge arm of the B-phase bridge arm, V B is the ac side reference phase voltage of the B-phase, H LB is the command signal of the B-phase loop, N BL is the number of half-bridge sub-modules of the lower bridge arm of the B-phase bridge arm, N CP is the ac side reference phase voltage of the C-phase, H LC is the command signal of the C-phase loop, and N CL is the number of half-bridge sub-modules of the lower bridge arm of the C-phase