CN-122026349-A - Hybrid energy storage black start power cooperative control method and system

CN122026349ACN 122026349 ACN122026349 ACN 122026349ACN-122026349-A

Abstract

The invention belongs to the technical field of safety and stability control and recovery of power systems, and relates to a hybrid energy storage black start power cooperative control method and system. The method comprises the steps of obtaining a comprehensive index of current anti-interference capability, obtaining the maximum transient frequency deviation based on the comprehensive index of the current anti-interference capability and power failure waiting time, selecting optimal loads and minimum influence factors of all candidate loads, further obtaining a power distribution coefficient of a next control period, generating and issuing a command to a load switch control system based on the optimal loads so as to switch the selected optimal loads at a preset moment, generating a reference power instruction of a super capacitor and a reference power instruction of a storage battery based on the power distribution coefficient of the next control period and power disturbance of a hybrid energy storage system, and repeating the steps until all planned recovered loads are put into or the hybrid energy storage system enters a stable running state. The invention realizes safe, rapid and self-adaptive black start.

Inventors

LI ZHIPENG
ZHANG LISONG
Dai Benqian
HE TING
Gao Yushuan
Lou Fangxi
JIANG NAN
XU HAITAO
LI SHUXUE
YANG LIYONG
LI GUANGSHAN
BA TEER
SUN GUOHUI
WANG XIAOHUI

Assignees

西安热工研究院有限公司
华能伊敏煤电有限责任公司

Dates

Publication Date: 20260512
Application Date: 20260414

Claims (10)

1. The hybrid energy storage black start power cooperative control method is characterized by comprising the following steps of: Acquiring a comprehensive index of the current disturbance rejection capability according to the current total active load variation per unit value of the power system, the frequency variation per unit value of the power system, the rated capacity of the started generator, the inertia constant of the started generator, the rated capacity of the hybrid energy storage system and the current reference capacity of the power system; Aiming at each candidate load in the load list to be restored, acquiring the maximum transient frequency deviation based on the comprehensive index of the current disturbance rejection capability and the power failure waiting time; selecting optimal loads and minimum influence factors of all candidate loads based on the per-unit value of the charge state of the super capacitor, the per-unit value of the charge state of the storage battery and the maximum transient frequency deviation; Acquiring a power distribution coefficient of the next control period based on the minimum influence factor, the charge state per unit value of the super capacitor and the charge state per unit value of the storage battery; generating a reference power instruction of a super capacitor and a reference power instruction of a storage battery based on a power distribution coefficient of the next control period and power disturbance of a hybrid energy storage system; repeating the steps until all the planned recovered loads are put into or the hybrid energy storage system enters a stable running state.
2. The hybrid energy storage black start power cooperative control method according to claim 1, further comprising: Acquiring a per unit value of the current total active load variation of the power system based on the current total active load variation of the power system, wherein the per unit value of the current total active load variation of the power system is shown in the following formula: the per unit value of the power system frequency variation is obtained based on the power system frequency variation, and the formula is as follows: the charge state per unit value of the super capacitor is obtained based on the charge state of the super capacitor, and the formula is as follows: and acquiring a charge state per unit value of the storage battery based on the charge state of the storage battery, wherein the charge state per unit value of the storage battery is represented by the following formula: Wherein, the The charge state per unit value of the super capacitor; The charge state per unit value of the storage battery; The current total active load variation per unit value of the power system; the per unit value of the frequency variation of the power system; the current total active load variation of the power system is obtained; The frequency variation of the power system is obtained; is a power reference value; is a frequency reference value; is the charge state of the super-capacitor, Is the state of charge of the battery.
3. The hybrid energy storage black start power cooperative control method according to claim 1, wherein the obtaining the comprehensive index of the current disturbance rejection capability according to the current total active load variation per unit value of the power system, the frequency variation per unit value of the power system, the rated capacity of the started generator, the inertia constant of the started generator, the rated capacity of the hybrid energy storage system and the current reference capacity of the power system comprises: Acquiring an equivalent damping coefficient of the system at the current moment according to the per unit value of the current total active load variation of the power system and the per unit value of the frequency variation of the power system; acquiring a system equivalent inertia time constant at the current moment according to the rated capacity of the started generator, the inertia constant of the started generator, the rated capacity of the hybrid energy storage system and the current reference capacity of the power system; And acquiring the comprehensive index of the current disturbance rejection capability according to the equivalent damping coefficient of the current moment system and the equivalent inertia time constant of the current moment system.
4. The hybrid energy storage black start power cooperative control method according to claim 3, wherein the obtaining formula of the equivalent damping coefficient of the system at the current moment is as follows: Wherein, the The equivalent damping coefficient of the system at the current moment; The current total active load variation per unit value of the power system; the per unit value of the frequency variation of the power system; Is rated frequency; is a system power reference value; the acquisition formula of the equivalent inertial time constant of the system at the current moment is as follows: Wherein, the The equivalent inertia time constant of the system at the current moment; rated capacity of the started generator; an inertia constant for the started generator; is an energy storage virtual inertia coefficient; rated capacity for the hybrid energy storage system; is the current reference capacity of the power system.
5. The hybrid energy storage black start power cooperative control method according to claim 1, wherein the obtaining formula of the comprehensive index of the current anti-interference capability is as follows: Wherein, the Is a comprehensive index of the current anti-interference capability; the equivalent inertia time constant of the system at the current moment; Is the rated angular frequency; is a system power reference value; The equivalent damping coefficient of the system at the current moment; is a control period; Is the current time.
6. The hybrid energy storage black start power cooperative control method according to claim 1, wherein the obtaining, for each candidate load in the load list to be restored, the maximum transient frequency deviation based on the comprehensive index of the current immunity and the power outage waiting time includes: For each candidate load in the load list to be recovered, acquiring an active power predicted value of the candidate load at a predicted time; acquiring the maximum transient frequency deviation based on an active power predicted value of the load at a predicted time, a comprehensive index of the current disturbance rejection capability and the power failure waiting time; the maximum transient frequency deviation is obtained according to the following formula: Wherein, the Is the maximum transient frequency deviation; is the first Predicted active power for each candidate load; is a system power reference value; is a comprehensive index of the current anti-interference capability; Correcting the coefficient for the load characteristic; the power failure waiting time; A cold start time constant for the load; is the current moment; to set the prediction step size.
7. The hybrid energy storage black start power cooperative control method according to claim 1, wherein the selecting optimal load and minimum influencing factor of all candidate loads based on the per-unit value of the state of charge of the super capacitor, the per-unit value of the state of charge of the storage battery and the maximum transient frequency deviation comprises: Acquiring a dynamic load recovery sequence influence factor based on the maximum transient frequency deviation, the charge state per unit value of the super capacitor and the charge state per unit value of the storage battery; Selecting optimal load and minimum influence factors based on the dynamic load recovery sequence influence factors of all candidate loads; The dynamic load recovery sequence influence factor has the following acquisition formula: Wherein, the Recovering sequence influencing factors for dynamic load; And Are all the weight coefficients of the two-dimensional space model, + =1; Is the maximum transient frequency deviation; Maximum frequency deviation allowed for the system; is the sensitivity coefficient of the unbalance degree of the energy storage SOC; The charge state per unit value of the super capacitor; The charge state per unit value of the storage battery; is the current moment; to set the prediction step size.
8. The hybrid energy storage black start power cooperative control method according to claim 1, wherein the power distribution coefficient of the next control period is obtained by the following formula: Wherein, the For the power allocation coefficient of the next control period, In order to influence the factor by adjusting the gain, In order to minimize the influence factor of the light, Is the per-unit value of the charge state of the super capacitor, Is the per unit value of the state of charge of the storage battery, Is a small amount for preventing and killing off; Is the current time.
9. The hybrid energy storage black start power cooperative control method according to claim 1, wherein the generating the reference power command of the super capacitor and the reference power command of the storage battery based on the power distribution coefficient of the next control period and the hybrid energy storage system power disturbance comprises: multiplying the reference power instruction of the super capacitor by reference power to obtain an actual power instruction of the super capacitor, and transmitting the actual power instruction of the super capacitor to the super capacitor; multiplying the reference power instruction of the storage battery by the reference power to obtain an actual power instruction of the storage battery, and transmitting the actual power instruction of the storage battery to a storage battery converter; The reference power command of the super capacitor is obtained by the following formula: the acquisition formula of the reference power instruction of the storage battery is as follows: Wherein, the A reference power instruction for the super capacitor; A power distribution coefficient for the next control period; Power disturbance of the hybrid energy storage system; Is a reference power command of the storage battery.
10. A hybrid energy storage black start power cooperative control system, comprising: The comprehensive index acquisition module is used for acquiring the comprehensive index of the current disturbance rejection capability according to the current total active load variation per unit value of the power system, the frequency variation per unit value of the power system, the rated capacity of the started generator, the inertia constant of the started generator, the rated capacity of the hybrid energy storage system and the current reference capacity of the power system; the maximum transient frequency deviation acquisition module is used for acquiring the maximum transient frequency deviation based on the comprehensive index of the current anti-interference capability and the power failure waiting time aiming at each candidate load in the load list to be restored; The minimum influence factor acquisition module is used for selecting the optimal load and the minimum influence factor of all candidate loads based on the per unit value of the charge state of the super capacitor, the per unit value of the charge state of the storage battery and the maximum transient frequency deviation; the power distribution coefficient acquisition module is used for acquiring the power distribution coefficient of the next control period based on the minimum influence factor, the charge state per unit value of the super capacitor and the charge state per unit value of the storage battery; The issuing execution instruction module is used for generating and issuing a command to a load switch control system based on the optimal load so as to switch the selected optimal load at a preset moment; And the rolling updating module is used for repeating the steps until all the planned recovered loads are put into or the hybrid energy storage system enters a stable running state.

Description

Hybrid energy storage black start power cooperative control method and system Technical Field The invention belongs to the technical field of safety and stability control and recovery of power systems, and relates to a hybrid energy storage black start power cooperative control method and system. Background The black start of the power system refers to a process of gradually recovering power supply by utilizing a power supply (such as a diesel generator, a hydroelectric generating set or an energy storage system) with self-starting capability in the system without depending on an external power grid after the system has large-area power failure. The process generally comprises the key steps of starting a power supply unit, establishing an island power grid, gradually recovering important loads and the like. In recent years, with the development of hybrid energy storage system (hes, hybrid Energy Storage System) composed of electrochemical energy storage (e.g. lithium battery) and power energy storage (e.g. super capacitor), the hybrid energy storage system has become an important technical means for assisting the conventional black start power supply by virtue of the characteristics of quick response and flexible regulation, and is especially suitable for providing frequency and voltage support for the power grid in the initial stage of load recovery. In the closest prior art, hybrid energy storage assisted black start schemes have been studied. One typical scenario is to pre-formulate a fixed load recovery sequence table and determine the recovery sequence based on rules (e.g., load importance, capacity size). Meanwhile, a fixed power distribution role is set for the super capacitor and the storage battery according to experience (for example, the super capacitor is responsible for restraining high-frequency fluctuation, the storage battery is responsible for providing basic power), or start-stop control is performed according to a simple State of Charge (SOC) threshold. Another approach to some improvement introduces frequency feedback, for example, by the hybrid energy storage system providing power support according to a preset scaling factor when a system frequency deviation exceeding a certain threshold is detected. Related documents (such as "hybrid energy storage-based microgrid black start optimization control" in volume 42 and 10 of electric power system automation 2018) also propose a load recovery sequence formulation method based on an optimization algorithm, but an optimization model is usually calculated offline before black start and depends on a preset power grid model and load data. Despite the advances made in the art, those skilled in the art will still find the following technical drawbacks and problems to be solved in practice: 1. The load recovery sequence formulation is disjointed with the real-time state of the system, and the adaptability is poor. The prior art relies heavily on a fixed load recovery sequence table that is pre-computed offline. However, during the black start dynamics, the equivalent inertia, damping characteristics and stored energy SOC state of the system are all changing in real time. A load switching operation considered "safe" in offline computing, performed when the real-time inertia of the system is low or the stored energy has been discharged deeply, may still cause excessive frequency drop, resulting in a black start failure. The prior art lacks a quantitative index capable of evaluating the load switching bearing capacity of the current system state on line and dynamically. 2. The energy storage power distribution strategy and the load recovery decision are mutually isolated and have insufficient synergy. In the existing scheme, the decision of the load recovery sequence and the power distribution control of the hybrid energy storage are often two independent loops. This results in the energy storage system not making optimal "preparatory actions" for the upcoming, specific load impact. For example, when it is determined that an impact load is to be recovered next, the energy storage system may not be adjusted to the optimal power distribution mode (e.g., insufficient reserved power of the supercapacitor), so that the impact cannot be most effectively stabilized, resulting in unnecessary frequency fluctuation. The decision and the execution level are cut, so that the transient stability and the efficiency of the overall recovery process are reduced. 3. The lack of consideration of the load history power failure state affects the prediction accuracy. In the prior art, when load switching influence analysis is carried out, only the predicted power of the load is generally considered, and the historical state of the load, namely the duration of power failure of the load, is ignored. In practice, the cold start current characteristics of the load such as the motor after a long-time power failure and the hot start characteristics after a short-time power failu