CN-117543692-B - Time difference fusion control method, system and device of virtual synchronous generator

CN117543692BCN 117543692 BCN117543692 BCN 117543692BCN-117543692-B

Abstract

The invention discloses a time difference fusion control method, a time difference fusion control system and a time difference fusion control device for a virtual synchronous generator, which relate to the technical field of virtual synchronous generators and have the technical scheme that a VSG control algorithm is adopted to calculate control parameters of VSG control; the control parameters of the current moment are decomposed into first parameters which participate in VSG control of the current moment and second parameters which participate in VSG control of the next moment, the first parameters which participate in VSG control of the current moment and the second parameters which participate in VSG control of the current moment and are decomposed at the previous moment are fused to obtain actual parameters of VSG control of the current moment, the actual parameters of VSG control of the current moment are input into double-loop control, and control signals for controlling on-off of a switching tube in an inverter are obtained after the control signals are processed through an SPWM modulator. The invention can effectively reduce the frequency and amplitude of primary frequency modulation under the condition of keeping the virtual inertia unchanged, and enhances the stability of distributed new energy grid connection.

Inventors

LI ZHONGYU
Man Yangyang
WANG XIANGFA
SHI KAI
XU XIAOHUA
XU GAOYUAN
LI ZHAOMING
WAN LI
XIANG ZHICAI
Gong chiyu
CHEN YANG
ZHANG XU
LIU XU
LI YUNDA
LIN YU
LI XINGYU

Assignees

国网山东省电力公司日照供电公司

Dates

Publication Date: 20260508
Application Date: 20231115

Claims (10)

1. The time difference fusion control method of the virtual synchronous generator is characterized by comprising the following steps of: collecting output power of the virtual synchronous generator during operation; comparing the output power with a power command of VSG control, and calculating control parameters of the VSG control by adopting a VSG control algorithm; decomposing the control parameter at the current moment into a first parameter participating in VSG control at the current moment and a second parameter participating in VSG control at the next moment; Fusing a first parameter participating in VSG control at the current moment with a second parameter participating in VSG control at the current moment and decomposed at the previous moment to obtain an actual parameter of VSG control at the current moment; The actual parameters of VSG control at the current moment are input into double-loop control, and control signals for controlling the on-off of a switching tube in the inverter are obtained after the control signals are processed by the SPWM modulator.
2. The time difference fusion control method of a virtual synchronous generator according to claim 1, wherein the control parameter is a power angle and/or a terminal voltage amplitude.
3. The time difference fusion control method of a virtual synchronous generator according to claim 1, wherein after the control parameters are decomposed, the absolute value of a first parameter participating in the VSG control at the current time is larger than the absolute value of a second parameter participating in the VSG control at the next time.
4. The time difference fusion control method of a virtual synchronous generator according to claim 1, wherein the process of decomposing the control parameter at the current time into a first parameter participating in VSG control at the current time and a second parameter participating in VSG control at the next time is specifically as follows: Calculating a first parameter participating in VSG control at the current moment by using the product of the control parameter at the current moment and the first decomposition coefficient; calculating a second parameter participating in VSG control at the next moment according to the difference between the control parameter at the current moment and the first parameter participating in VSG control at the current moment; Wherein the first decomposition coefficient is greater than 0.5 and less than 1.
5. The time difference fusion control method of a virtual synchronous generator according to claim 4, wherein the first decomposition coefficient is determined by a fluctuation range of output power; wherein the larger the fluctuation amplitude of the output power is, the smaller the first decomposition coefficient is.
6. The time difference fusion control method of a virtual synchronous generator according to claim 1, wherein the process of decomposing the control parameter at the current time into a first parameter participating in VSG control at the current time and a second parameter participating in VSG control at the next time is specifically as follows: Calculating to obtain parameter variables according to the difference between the control parameters at the current moment and the actual parameters at the previous moment; calculating a second parameter participating in VSG control at the next moment by using the product of the parameter variable and the second decomposition coefficient; Calculating to obtain a first parameter participating in VSG control at the current moment according to the difference between the control parameter at the current moment and a second parameter participating in VSG control at the next moment; Wherein the second decomposition coefficient is greater than 0 and less than 1.
7. The time difference fusion control method of a virtual synchronous generator according to claim 6, wherein the second decomposition coefficient is determined by a fluctuation range of output power; wherein the larger the fluctuation amplitude of the output power is, the larger the second decomposition coefficient is.
8. The time difference fusion control method of a virtual synchronous generator according to claim 1, wherein the calculation formula of the actual parameters is specifically as follows: B i ＝β i,1 +β i-1,2 ; Wherein B i represents the actual parameter of the VSG control at the i time, beta i,1 represents the first parameter of the VSG control at the i time after the control parameter at the i time is decomposed, and beta i-1,2 represents the second parameter of the VSG control at the i time after the control parameter at the i-1 time is decomposed.
9. A time difference fusion control system of a virtual synchronous generator, comprising: the data acquisition module is used for acquiring the output power of the virtual synchronous generator during operation; the initial control module is used for comparing the output power with a power instruction of VSG control and calculating control parameters of the VSG control by adopting a VSG control algorithm; The parameter decomposition module is used for decomposing the control parameter at the current moment into a first parameter participating in VSG control at the current moment and a second parameter participating in VSG control at the next moment; The parameter fusion module is used for fusing the first parameter which participates in the VSG control at the current moment and the second parameter which participates in the VSG control at the current moment and is decomposed at the previous moment to obtain the actual parameter of the VSG control at the current moment; The signal modulation module is used for inputting actual parameters controlled by the VSG at the current moment into the double-loop control, and obtaining a control signal for controlling the on-off of a switching tube in the inverter after the control signal is processed by the SPWM modulator.
10. A VSG grid-tie device comprising a distributed photovoltaic power generation unit, an inverter, and at least one time difference fusion control system of a virtual synchronous generator as defined in claim 9; the distributed photovoltaic power generation units are connected into a power grid system through an inverter grid connection; the data acquisition module acquires output power of an output side of the inverter; And a control signal generated by the time difference fusion control system of the virtual synchronous generator controls the on-off of a switching tube in the inverter.

Description

Time difference fusion control method, system and device of virtual synchronous generator Technical Field The invention relates to the technical field of virtual synchronous generators, in particular to a time difference fusion control method, a time difference fusion control system and a time difference fusion control device of a virtual synchronous generator. Background With more and more distributed energy sources being connected to a power grid through an electric power inverter, the electric power inverter has the advantage of high response speed, but does not have the mechanical inertia and damping characteristics of a traditional synchronous engine, and cannot provide inertia and damping for a system, so that the excessive distributed energy sources are connected to the power grid, and the power system is easy to lose stability. The virtual synchronous generator (Virtual Synchronous Generator, VSG) is a control algorithm of embedding a mathematical model of the synchronous generator into an inverter, simulating a static power electronic device as an operation technology of a rotating motor, and enabling the virtual synchronous generator to have the functions of damping voltage and frequency rapid fluctuation, automatic power distribution, synchronous power grid operation and the like by simulating primary frequency modulation and voltage regulation of the synchronous generator. In the whole VSG grid-connected device, a distributed new energy power generation unit is used as a virtual prime motor, an inverter is used as a virtual generator, output power is generally compared with a power instruction of VSG control during primary frequency modulation, control parameters (such as attack angle and machine end voltage amplitude) of the VSG control are calculated by adopting a VSG control algorithm, the control parameters are input into double-loop control, and a control signal for controlling on-off of a switching tube in the inverter is obtained after processing through a SPWM (Sinusoidal PWM) modulator, so that output power of an output side of the inverter is regulated to adapt to load fluctuation. However, when the load fluctuation amplitude is large, the virtual inertia of the virtual synchronous generator needs to be large enough, and when the virtual inertia is insufficient to finish the rapid fluctuation of power, the power input of the virtual prime motor needs to be regulated to realize primary frequency modulation, and the frequency recovery is performed after the system power is balanced. When the load rapidly fluctuates in a large extent, the problems of large primary frequency modulation frequency and large primary frequency modulation amplitude exist, and the stability of the distributed new energy grid connection needs to be further improved. Therefore, how to study and design a time difference fusion control method, system and device of a virtual synchronous generator capable of overcoming the above defects is an urgent problem to be solved at present. Disclosure of Invention In order to solve the defects in the prior art, the invention aims to provide a time difference fusion control method, a system and a device for a virtual synchronous generator, which are used for carrying out superposition fusion on parameters at two adjacent moments when loads are greatly and rapidly fluctuated, and can offset the adjacent fluctuation, so that the actual parameter fluctuation of VSG control is smaller, the frequency and amplitude of primary frequency modulation can be effectively reduced under the condition that virtual inertia is kept unchanged, and the stability of grid connection of distributed new energy sources is enhanced. The technical aim of the invention is realized by the following technical scheme: in a first aspect, a time difference fusion control method of a virtual synchronous generator is provided, including the following steps: collecting output power of the virtual synchronous generator during operation; comparing the output power with a power command of VSG control, and calculating control parameters of the VSG control by adopting a VSG control algorithm; decomposing the control parameter at the current moment into a first parameter participating in VSG control at the current moment and a second parameter participating in VSG control at the next moment; Fusing a first parameter participating in VSG control at the current moment with a second parameter participating in VSG control at the current moment and decomposed at the previous moment to obtain an actual parameter of VSG control at the current moment; The actual parameters of VSG control at the current moment are input into double-loop control, and control signals for controlling the on-off of a switching tube in the inverter are obtained after the control signals are processed by the SPWM modulator. Further, the control parameter is attack angle and/or terminal voltage amplitude. Further, after the control parameters are dec