CN-122026361-A - Self-adaptive coordination stable control method of optical storage integrated off-grid network energy storage system

Abstract

The invention discloses a self-adaptive coordination stable control method of an optical storage integrated off-grid energy storage system, which comprises a photovoltaic power generation unit, an energy storage unit, an integrated converter, a local load and a system controller, and is characterized in that the system controller performs the following steps of constructing a self-adaptive virtual synchronous mechanism network control layer, wherein the self-adaptive virtual synchronous mechanism network control layer is used for carrying out self-adaptive adjustment on control parameters of a virtual synchronous machine according to the state of the energy storage unit and the dynamic behavior of the system; and generating a feedforward compensation signal according to the load prediction result and superposing the feedforward compensation signal to a power reference value of a virtual synchronous machine control layer, and carrying out feedback adjustment on the power deviation and the frequency voltage deviation through the virtual synchronous machine control layer.

Inventors

• LIU XIAOYU
• ZHANG LEI
• LI HAIDONG

Assignees

• 北京雷动智创科技有限公司

Dates

Publication Date

20260512

Application Date

20260211

Claims (7)

1. 1. The self-adaptive coordination stable control method of the light storage integrated off-grid energy storage system is characterized in that the system comprises a photovoltaic power generation unit, an energy storage unit, an integrated converter, a local load and a system controller, and the system controller performs the following steps: Constructing a self-adaptive virtual synchronous mechanism network control layer, wherein the self-adaptive virtual synchronous mechanism network control layer is used for carrying out self-adaptive adjustment on control parameters of a virtual synchronous machine according to the state of an energy storage unit and the dynamic behavior of a system; Monitoring photovoltaic power, energy storage state and load power in real time, and predicting a load change trend to obtain a load prediction result; And generating a feedforward compensation signal according to the load prediction result, superposing the feedforward compensation signal to a power reference value of a virtual synchronous machine control layer, and carrying out feedback adjustment on the power deviation and the frequency voltage deviation through the virtual synchronous machine control layer.
2. 2. The adaptive coordination stability control method of an optical storage integrated off-grid energy storage system according to claim 1, wherein the adaptive adjustment of control parameters of a virtual synchronous machine according to the state of an energy storage unit and the dynamic behavior of the system comprises: and determining the adjustment quantity of the virtual moment of inertia and the sagging coefficient according to the charge state of the energy storage unit and the change rate of the system frequency.
3. 3. The adaptive coordinated stabilization control method of an optical storage integrated off-grid energy storage system according to claim 2, wherein determining the adjustment amounts of the virtual moment of inertia and the sag coefficient comprises: when the charge state of the energy storage unit is higher than a first threshold value, increasing virtual moment of inertia; When the charge state of the energy storage unit is lower than a second threshold value, reducing virtual moment of inertia; and locking the voltage phase by using a phase-locked loop (PLL), calculating the frequency, deriving the system frequency change rate, and increasing the virtual moment of inertia and the virtual damping coefficient when the absolute value of the system frequency change rate exceeds a third threshold value.
4. 4. The adaptive coordination stability control method of an optical storage integrated off-grid energy storage system according to claim 1, wherein the predicting the load change trend, obtaining the load prediction result comprises: according to the photovoltaic power, the energy storage state and the load power, dynamically adjusting an active power reference value and a reactive power reference value of the integrated converter; and generating a load prediction result in a future time window by combining time sequence analysis of historical load data or start-stop signals of load equipment based on the adjusted reference value.
5. 5. The adaptive coordinated stabilization control method of an optical storage integrated off-grid energy storage system according to claim 1, wherein generating a feedforward compensation signal according to the load prediction result and superimposing the feedforward compensation signal to a power reference value of a virtual synchronous machine control layer comprises: determining a load variation amount based on the load prediction result; Calculating a feedforward compensation signal according to the load variation and the feedforward compensation coefficient; And the feedforward compensation signal is overlapped to the power reference value of the virtual synchronous machine control layer, and a new power reference value is generated.
6. 6. The adaptive coordinated stabilization control method of an optical storage integrated off-grid energy storage system of claim 5, wherein the feedforward compensation coefficient is dynamically adjusted according to the real-time adjustable power capacity and state of charge of the energy storage unit.
7. 7. The self-adaptive coordination stable control method of the light storage integrated off-grid energy storage system according to claim 1, wherein the integrated converter integrates a DC/DC converter and a DC/AC inverter and is used for realizing power conversion between a photovoltaic power generation unit and an energy storage unit and a local load; the system controller collects direct current bus voltage, alternating current side voltage and current and state of charge information of the energy storage unit through the sensor.

Description

Self-adaptive coordination stable control method of optical storage integrated off-grid network energy storage system Technical Field The invention belongs to the technical field of new energy power generation and energy storage system control, and particularly relates to a self-adaptive coordination stable control method of an optical storage integrated off-grid energy storage system. Background With the popularization of renewable energy sources, off-grid optical storage systems are increasingly used in remote areas, emergency power supply and specific industrial scenes. In off-grid mode, the system loses support of a large grid, and the voltage and frequency stability of the system is completely dependent on the power supply inside the system. In conventional optical storage systems, energy storage converters often employ a "grid-following" control strategy, which relies on stable grid voltage and frequency. However, in the off-grid mode, no power grid capable of 'following' exists, the inertia and stability of the system are poor, severe fluctuation of load is difficult to cope with, and system breakdown is easy to cause. However, the existing new energy off-grid networking technology has obvious bottlenecks, such as difficult source-core matching, poor system stability and the like, so that a novel optical storage off-grid system solution which can completely run off-grid, efficiently integrate the fluctuation new energy and realize source-storage-load dynamic balance and stable running through intelligent control is needed in the field. Disclosure of Invention In order to solve the technical problems, the invention provides a self-adaptive coordination stable control method of an optical storage integrated off-grid network energy storage system, which is characterized in that a core network strategy combining a virtual synchronous machine and self-adaptive droop control is constructed, and a feed-forward-feedback coordination mechanism based on load prediction and energy storage state is introduced, so that quick, smooth and self-adaptive response to changing load is realized, and long-term stable operation of the off-grid system is ensured. In order to achieve the above purpose, the invention provides a self-adaptive coordination stable control method of an optical storage integrated off-grid energy storage system, wherein the system comprises a photovoltaic power generation unit, an energy storage unit, an integrated converter, a local load and a system controller, and the system controller executes the following steps: Constructing a self-adaptive virtual synchronous mechanism network control layer, wherein the self-adaptive virtual synchronous mechanism network control layer is used for carrying out self-adaptive adjustment on control parameters of a virtual synchronous machine according to the state of an energy storage unit and the dynamic behavior of a system; Monitoring photovoltaic power, energy storage state and load power in real time, and predicting a load change trend to obtain a load prediction result; And generating a feedforward compensation signal according to the load prediction result, superposing the feedforward compensation signal to a power reference value of a virtual synchronous machine control layer, and carrying out feedback adjustment on the power deviation and the frequency voltage deviation through the virtual synchronous machine control layer. Optionally, performing adaptive adjustment on the control parameters of the virtual synchronous machine according to the state of the energy storage unit and the dynamic behavior of the system includes: and determining the adjustment quantity of the virtual moment of inertia and the sagging coefficient according to the charge state of the energy storage unit and the change rate of the system frequency. Optionally, the determining the adjustment amounts of the virtual moment of inertia and the sagging coefficient includes: when the charge state of the energy storage unit is higher than a first threshold value, increasing virtual moment of inertia; When the charge state of the energy storage unit is lower than a second threshold value, reducing virtual moment of inertia; and locking the voltage phase by using a phase-locked loop (PLL), calculating the frequency, deriving the system frequency change rate, and increasing the virtual moment of inertia and the virtual damping coefficient when the absolute value of the system frequency change rate exceeds a third threshold value. Optionally, the predicting the load change trend, and obtaining the load prediction result includes: according to the photovoltaic power, the energy storage state and the load power, dynamically adjusting an active power reference value and a reactive power reference value of the integrated converter; and generating a load prediction result in a future time window by combining time sequence analysis of historical load data or start-stop signals of load equipment b