[go: up one dir, main page]

CN113258775A - Active damping control method for direct-current micro-grid - Google Patents

Active damping control method for direct-current micro-grid Download PDF

Info

Publication number
CN113258775A
CN113258775A CN202110631482.0A CN202110631482A CN113258775A CN 113258775 A CN113258775 A CN 113258775A CN 202110631482 A CN202110631482 A CN 202110631482A CN 113258775 A CN113258775 A CN 113258775A
Authority
CN
China
Prior art keywords
converter
battery
bidirectional
active damping
direct current
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202110631482.0A
Other languages
Chinese (zh)
Inventor
尹子晨
彭超
蔡明君
唐欣
柴金超
李勇
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Changsha University of Science and Technology
Original Assignee
Changsha University of Science and Technology
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Changsha University of Science and Technology filed Critical Changsha University of Science and Technology
Priority to CN202110631482.0A priority Critical patent/CN113258775A/en
Publication of CN113258775A publication Critical patent/CN113258775A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M3/00—Conversion of DC power input into DC power output
    • H02M3/02—Conversion of DC power input into DC power output without intermediate conversion into AC
    • H02M3/04—Conversion of DC power input into DC power output without intermediate conversion into AC by static converters
    • H02M3/10—Conversion of DC power input into DC power output without intermediate conversion into AC by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M3/145—Conversion of DC power input into DC power output without intermediate conversion into AC by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
    • H02M3/155—Conversion of DC power input into DC power output without intermediate conversion into AC by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M3/156—Conversion of DC power input into DC power output without intermediate conversion into AC by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators
    • H02M3/158—Conversion of DC power input into DC power output without intermediate conversion into AC by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators including plural semiconductor devices as final control devices for a single load
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for AC mains or AC distribution networks
    • H02J3/12—Circuit arrangements for AC mains or AC distribution networks for adjusting voltage in AC networks by changing a characteristic of the network load
    • H02J3/14—Circuit arrangements for AC mains or AC distribution networks for adjusting voltage in AC networks by changing a characteristic of the network load by switching loads on to, or off from, network, e.g. progressively balanced loading
    • H02J3/144—Demand-response operation of the power transmission or distribution network
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for AC mains or AC distribution networks
    • H02J3/24—Arrangements for preventing or reducing oscillations of power in networks
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for AC mains or AC distribution networks
    • H02J3/28—Arrangements for balancing of the load in a network by storage of energy
    • H02J3/32—Arrangements for balancing of the load in a network by storage of energy using batteries with converting means
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for AC mains or AC distribution networks
    • H02J3/36—Arrangements for transfer of electric power between AC networks via a high-tension DC link
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for AC mains or AC distribution networks
    • H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/08—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters
    • H02M1/088—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters for the simultaneous control of series or parallel connected semiconductor devices
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J2300/00—Systems for supplying or distributing electric power characterised by decentralized, dispersed, or local generation
    • H02J2300/20—The dispersed energy generation being of renewable origin
    • H02J2300/22—The renewable source being solar energy
    • H02J2300/24—The renewable source being solar energy of photovoltaic origin
    • H02J2300/26—The renewable source being solar energy of photovoltaic origin involving maximum power point tracking control for photovoltaic sources
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J2300/00—Systems for supplying or distributing electric power characterised by decentralized, dispersed, or local generation
    • H02J2300/20—The dispersed energy generation being of renewable origin
    • H02J2300/28—The renewable source being wind energy
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
    • Y02B70/30—Systems integrating technologies related to power network operation and communication or information technologies for improving the carbon footprint of the management of residential or tertiary loads, i.e. smart grids as climate change mitigation technology in the buildings sector, including also the last stages of power distribution and the control, monitoring or operating management systems at local level
    • Y02B70/3225—Demand response systems, e.g. load shedding, peak shaving
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/50—Photovoltaic [PV] energy
    • Y02E10/56—Power conversion systems, e.g. maximum power point trackers
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/60—Arrangements for transfer of electric power between AC networks or generators via a high voltage DC link [HVCD]
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y04—INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
    • Y04S—SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
    • Y04S20/00—Management or operation of end-user stationary applications or the last stages of power distribution; Controlling, monitoring or operating thereof
    • Y04S20/20—End-user application control systems
    • Y04S20/222—Demand response systems, e.g. load shedding, peak shaving

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Dc-Dc Converters (AREA)

Abstract

The invention discloses an active damping control method of a bidirectional DC/DC converter of a direct-current micro-grid, belonging to the field of direct-current micro-grids. The method comprises the steps of establishing a direct current micro-grid model, simplifying the direct current micro-grid model, establishing a small-signal model, measuring signals, controlling active damping and solving the duty ratio. The invention adopts a virtual resistance control method to perform impedance remodeling, and reduces the amplitude of the output impedance of the bidirectional DC/DC converter to be far smaller than that of the output impedance of the load converter. The low-frequency amplitude of the output impedance is not changed, a hardware circuit is not added, the loss is not increased, the tidal current distribution of a system is not changed, the stability of the direct-current micro-grid is improved, and the safe and stable operation of the direct-current micro-grid is facilitated.

Description

一种直流微电网有源阻尼控制方法An Active Damping Control Method for DC Microgrid

技术领域technical field

本发明涉及一种应用于直流微电网蓄电池双向DC/DC变换器的有源阻尼控制方法，进行阻抗重塑，降低蓄电池双向DC/DC变换器的输出阻抗峰值，从而提高系统的稳定性，属于直流微电网领域。The invention relates to an active damping control method applied to a bidirectional DC/DC converter of a direct current microgrid battery, which performs impedance reshaping, reduces the output impedance peak value of the bidirectional DC/DC converter of the battery, and thus improves the stability of the system, and belongs to DC microgrid field.

背景技术Background technique

随着经济的发展，人们对于电力的需求与日俱增。传统的电网大多数都是以化石燃料作为一次能源，会造成温室效应、环境污染等问题。为了解决上述存在的问题，国内外的科学家提出了微电网的概念。微电网由分布式发电单元、储能单元和负荷共同组成，内部主要由电力电子变换器负责能量的转换和控制，以适应本地负荷对可靠性和安全性的要求。其作为一个独立的整体，可以采取并网模式运行，也可孤岛模式运行。按照配电方式可分为交流微电网和直流微电网。相比于交流微电网，直流微电网主要优势体现在无需跟踪频率与相位，只需控制直流母线电压，线路成本和损耗低，且无需考虑无功损耗和稳定性问题，电网运行可靠性更高。With the development of economy, people's demand for electricity is increasing day by day. Most of the traditional power grids use fossil fuels as primary energy, which will cause problems such as greenhouse effect and environmental pollution. In order to solve the above-mentioned problems, scientists at home and abroad have proposed the concept of microgrid. The microgrid is composed of distributed generation units, energy storage units and loads. The power electronic converter is mainly responsible for energy conversion and control inside to meet the reliability and safety requirements of local loads. As an independent whole, it can operate in grid-connected mode or in island mode. According to the distribution mode, it can be divided into AC microgrid and DC microgrid. Compared with the AC microgrid, the main advantage of the DC microgrid is that it does not need to track the frequency and phase, but only needs to control the DC bus voltage, the line cost and loss are low, and there is no need to consider the reactive power loss and stability issues, and the grid operation reliability is higher. .

随着直流微电网的系统结构的发展与负荷种类的增多，其设计的可靠性与运行的稳定性要求逐渐提高，系统稳定性的研究更为重要与复杂。首先，直流微电网含有大量电子设备，当其处于工作状态时，各设备的控制参数之间的相互影响可能引起微电网的高频振荡；其次，微电网中的储能、微源及负载均通过变换器并联与直流母线相连，选用不同的控制结构或不同的控制策略使变换器的输出等效阻抗不同，有可能由于阻抗的不匹配使母线电压的发生震荡。With the development of the system structure of the DC microgrid and the increase of load types, the reliability of its design and the stability of its operation are gradually improved, and the study of system stability is more important and complex. First, the DC microgrid contains a large number of electronic devices. When it is in the working state, the interaction between the control parameters of each device may cause high-frequency oscillation of the microgrid; secondly, the energy storage, microsources and loads in the microgrid are all The converter is connected in parallel with the DC bus, and different control structures or different control strategies are selected to make the output equivalent impedance of the converter different, and the bus voltage may oscillate due to the mismatch of impedance.

目前提高直流微电网的稳定性的措施主要有有源阻尼法和无源阻尼法。无源阻尼法虽然提高了系统的稳定性，但需要额外的其他硬件设备，增加了系统所需要的体积、成本和损耗，并且转换效率低。目前所提的有源阻尼方法，虽然无需增加硬件电路、无损耗，易于实现，但是增加变流器在低频段的输出阻抗，影响系统稳态潮流分布。At present, the measures to improve the stability of DC microgrid mainly include active damping method and passive damping method. Although the passive damping method improves the stability of the system, it requires additional hardware equipment, increases the volume, cost and loss required by the system, and has low conversion efficiency. Although the proposed active damping method does not need to add hardware circuit, has no loss, and is easy to implement, it increases the output impedance of the converter in the low frequency band, which affects the steady-state power flow distribution of the system.

发明内容SUMMARY OF THE INVENTION

本发明提供了一种直流微电网蓄电池双向DC/DC变换器的有源阻尼控制方法。其目的是为了解决直流微电网中选用不同的控制结构或者不同的控制策略使变换器的输出等效阻抗不同，导致母线电压发生震荡，导致系统的不稳定。The invention provides an active damping control method for a bidirectional DC/DC converter of a DC microgrid battery. The purpose is to solve the problem that different control structures or different control strategies are used in the DC microgrid to make the output equivalent impedance of the converter different, which will cause the bus voltage to oscillate and cause the system to become unstable.

为了达到上述目的，本发明的实施例提供了一种直流微电网蓄电池双向DC/DC变换器的有源阻尼控制方法，包括：In order to achieve the above purpose, an embodiment of the present invention provides an active damping control method for a bidirectional DC/DC converter of a DC microgrid battery, including:

步骤1，搭建直流微电网模型：所述直流微电网包含分布式发电单元、储能单元和负荷单元。所述分布式发电单元通常由风机、光伏等可再生能源构成，通过AC/DC或DC/DC变流器接入直流母线；所述储能单元主要是蓄电池、超级电容等储能设备，通过双向DC/DC变流器接入直流母线；所述负荷单元大致可以分为交流负荷和直流负荷，通过相应的AC/DC或DC/DC变流器接入直流母线；所述直流微电网包含的分布式发电单元、储能单元和负荷单元均包括变流器、控制系统、测量元件；所述直流微电网包含的分布式发电单元、储能单元和负荷单元的控制系统输入端分别与相应的测量元件输出端相连，其输出端与相应的变换器输入端相连；所述直流微电网中测量元件主要包括分布式发电单元、储能单元和负荷单元的直流母线侧电压传感器和电流传感器以及分布式电源侧、蓄电池侧和恒功率负荷侧的电压传感器和电流传感器等。Step 1, build a DC microgrid model: the DC microgrid includes a distributed generation unit, an energy storage unit and a load unit. The distributed power generation unit is usually composed of renewable energy sources such as wind turbines and photovoltaics, and is connected to the DC bus through AC/DC or DC/DC converters; the energy storage units are mainly energy storage devices such as batteries and super capacitors. The bidirectional DC/DC converter is connected to the DC bus; the load unit can be roughly divided into an AC load and a DC load, and is connected to the DC bus through the corresponding AC/DC or DC/DC converter; the DC microgrid includes The distributed generation unit, the energy storage unit and the load unit all include a converter, a control system, and a measuring element; the input ends of the control system of the distributed generation unit, the energy storage unit and the load unit included in the DC microgrid are respectively corresponding to the corresponding input terminals. The output end of the measuring element is connected to the output end of the measuring element, and its output end is connected to the corresponding input end of the converter; the measuring element in the DC microgrid mainly includes the DC bus side voltage sensor and current sensor of the distributed generation unit, the energy storage unit and the load unit, and the Voltage sensors and current sensors on the distributed power supply side, battery side and constant power load side, etc.

步骤2，直流微电网模型的化简：风、光等间歇性分布式电源采用最大功率跟踪策略以最大限度利用可再生能源。对于采用功率控制的变流器来说，由于其与恒功率负荷具有相似的外特性，在建模时可以视为一种输出功率为负的特殊类型的恒功率负荷。因此，直流微电网可以简化成为包含双向DC/DC变流器、电阻性负荷和恒功率负荷的等效模型。Step 2, the simplification of the DC microgrid model: the intermittent distributed power sources such as wind and light use the maximum power tracking strategy to maximize the use of renewable energy. For the converter with power control, it can be regarded as a special type of constant power load with negative output power during modeling because it has similar external characteristics to the constant power load. Therefore, the DC microgrid can be simplified into an equivalent model including bidirectional DC/DC converters, resistive loads and constant power loads.

步骤3，建立小信号模型：通过状态空间平均法建立双向DC/DC变换器小信号模型，得到双向DC/DC变换器的输出阻抗。将通过采用母线电压外环和电感电流内环相结合的双闭环控制策略设计控制器的参数。根据Middlebrook阻抗判据，为保证级联系统的稳定性，应满足源变换器输出阻抗Zbc和负载变换器阻抗ZL的阻抗比Tm＝Zbc(s)/ZL(s)的奈奎斯特曲线不包含点(-1，0)。通过改变源级变换器的阻抗使得与负载变换器不相交的方法来改变系统的稳定性。Step 3, establish a small-signal model: establish a small-signal model of the bidirectional DC/DC converter through the state space averaging method, and obtain the output impedance of the bidirectional DC/DC converter. The parameters of the controller will be designed by adopting a double closed-loop control strategy combining the bus voltage outer loop and the inductor current inner loop. According to the Middlebrook impedance criterion, in order to ensure the stability of the cascaded system, the impedance ratio T m =Z bc (s)/Z L (s) of the output impedance Z bc of the source converter and the impedance Z L of the load converter should be satisfied. A quist curve does not contain the point (-1, 0). The stability of the system is changed by changing the impedance of the source converter so that it does not intersect with the load converter.

步骤4，信号测量：通过直流母线侧电压传感器测量直流微电网中直流母线电压udc，通过蓄电池侧电压传感器测量蓄电池输入电压ub，通过蓄电池侧电流传感器测量蓄电池输入电流ib和直流母线侧电流idc。Step 4, signal measurement: measure the DC bus voltage u dc in the DC micro-grid by the DC bus side voltage sensor, measure the battery input voltage u b by the battery side voltage sensor, measure the battery input current ib and the DC bus side by the battery side current sensor current i dc .

步骤5，有源阻尼控制：并联虚拟电阻的方法对电源侧输出阻抗进行校正。在蓄电池双向DC/DC变换器侧并联电阻能够提升级联系统的稳定性，但物理电阻会增加成本且电阻值不能够灵活取值。通过控制结构的等效变换提出了一种虚拟电阻控制方法来提高系统的稳定性。本控制只是在原本控制的基础上增加一个前馈通路，方法简单可行，实现较为方便。通过直流母线侧电压传感器测量直流微电网中直流母线电压udc乘以系数k(k＝1/RvD)反馈至电压环PI控制器的输出进行比较产生电流环的给定值。Step 5, active damping control: correcting the output impedance of the power supply side by means of a parallel virtual resistor. Parallel resistance on the side of the bidirectional DC/DC converter of the battery can improve the stability of the cascade system, but the physical resistance will increase the cost and the resistance value cannot be flexibly selected. Through the equivalent transformation of the control structure, a virtual resistance control method is proposed to improve the stability of the system. This control only adds a feedforward path on the basis of the original control, the method is simple and feasible, and the realization is relatively convenient. The DC bus voltage u dc in the DC microgrid is measured by the DC bus side voltage sensor, multiplied by the coefficient k (k=1/R v D) and fed back to the output of the voltage loop PI controller for comparison to generate a given value of the current loop.

步骤6，求取占空比：计算得到所述蓄电池DC/DC变换器的占空比D，将控制信号送入所述蓄电池DC/DC变换器的开关管进行PWM调制控制。Step 6: Obtain the duty ratio: Calculate the duty ratio D of the battery DC/DC converter, and send the control signal to the switch tube of the battery DC/DC converter for PWM modulation control.

本发明的上述方案有如下的有益效果：The above-mentioned scheme of the present invention has the following beneficial effects:

本发明采用一种直流微电网蓄电池双向DC/DC变换器的有源阻尼控制方法。将双向DC/DC变换器输出阻抗幅值降为远小于负载变换器的输出阻抗，不改变输出阻抗低频率幅值，不改变系统的潮流分布，无需增加硬件电路、无损耗的优点，提高直流微电网的稳定性。The invention adopts an active damping control method of a bidirectional DC/DC converter of a direct current microgrid battery. Reduce the output impedance amplitude of the bidirectional DC/DC converter to be much smaller than the output impedance of the load converter, do not change the low frequency amplitude of the output impedance, do not change the power flow distribution of the system, do not need to increase the hardware circuit, no loss advantages, improve the DC Microgrid stability.

附图说明Description of drawings

图1为直流微电网拓扑结构图Figure 1 shows the topology of the DC microgrid

图2为储能双向DC/DC变换器拓扑结构图Figure 2 shows the topology of the energy storage bidirectional DC/DC converter

图3为储能双向DC/DC变换器控制框图Figure 3 is the control block diagram of the energy storage bidirectional DC/DC converter

图4为仅PI控制的直流母线电压波形图Figure 4 shows the DC bus voltage waveform of only PI control

图5为加入虚拟电阻有源阻尼控制母线电压波形图Fig. 5 is the bus voltage waveform diagram of adding virtual resistance active damping control

具体实施方式Detailed ways

为使本发明要解决的技术问题、技术方案和优点更加清楚，下面将结合附图及具体实施例进行详细描述。In order to make the technical problems, technical solutions and advantages to be solved by the present invention more clear, the following will be described in detail with reference to the accompanying drawings and specific embodiments.

本发明针对微电网中的储能、微源及负载均通过变换器并联与直流母线相连，选用不同的控制结构或不同的控制策略使变换器的输出等效阻抗不同，有可能由于阻抗的不匹配使母线电压的发生震荡，提供了一种直流微电网蓄电池双向DC/DC变换器的有源阻尼控制方法。According to the invention, the energy storage, micro-source and load in the micro-grid are connected in parallel with the DC bus through the converter, and different control structures or different control strategies are selected to make the output equivalent impedance of the converter different. The matching causes the busbar voltage to oscillate, and provides an active damping control method for a bidirectional DC/DC converter of a DC microgrid battery.

如图1至图3所示，本发明的实施例提供了一种直流微电网蓄电池双向DC/DC变换器的有源阻尼控制方法，包括：步骤1，搭建直流微电网模型：所述直流微电网包含分布式发电单元、储能单元和负荷单元；步骤2，直流微电网模型的化简，建模时可以视风、光为一种输出功率为负的特殊类型的恒功率负荷；步骤3，建立小信号模型：通过状态空间平均法建立双向DC/DC变换器小信号模型，得到双向DC/DC变换器的输出阻抗。步骤4，信号测量：通过直流母线侧电压传感器测量直流微电网中直流母线电压udc，通过蓄电池侧电压传感器测量蓄电池输入电压ub，通过蓄电池侧电流传感器测量蓄电池输入电流ib和直流母线侧电流idc。步骤5，有源阻尼控制：并联虚拟电阻的方法对电源侧输出阻抗进行校正。在蓄电池双向DC/DC变换器侧并联电阻能够提升级联系统的稳定性。As shown in FIGS. 1 to 3 , an embodiment of the present invention provides an active damping control method for a bidirectional DC/DC converter of a DC microgrid battery, including: step 1, building a DC microgrid model: the DC microgrid The power grid includes distributed generation units, energy storage units and load units; step 2, simplification of the DC microgrid model, wind and light can be regarded as a special type of constant power load with negative output power during modeling; step 3 , establish the small signal model: establish the small signal model of the bidirectional DC/DC converter through the state space averaging method, and obtain the output impedance of the bidirectional DC/DC converter. Step 4, signal measurement: measure the DC bus voltage u dc in the DC micro-grid by the DC bus side voltage sensor, measure the battery input voltage u b by the battery side voltage sensor, measure the battery input current ib and the DC bus side by the battery side current sensor current i dc . Step 5, active damping control: correcting the output impedance of the power supply side by means of a parallel virtual resistor. Parallel resistance on the side of the battery bidirectional DC/DC converter can improve the stability of the cascade system.

其中，所述步骤2具体包括：风、光等间歇性分布式电源采用最大功率跟踪策略以最大限度利用可再生能源。对于采用功率控制的变流器来说，由于其与恒功率负荷具有相似的外特性，在建模时可以视为一种输出功率为负的特殊类型的恒功率负荷。因此，直流微电网可以简化成为包含双向DC/DC变流器、电阻性负荷和恒功率负荷的等效模型。Wherein, the step 2 specifically includes: adopting a maximum power tracking strategy for intermittent distributed power sources such as wind and light to maximize the use of renewable energy. For the converter with power control, it can be regarded as a special type of constant power load with negative output power during modeling because it has similar external characteristics to the constant power load. Therefore, the DC microgrid can be simplified into an equivalent model including bidirectional DC/DC converters, resistive loads and constant power loads.

其中，所述步骤3具体包括：通过状态空间平均法建立双向DC/DC变换器小信号模型，得到双向DC/DC变换器的输出阻抗。将通过采用母线电压外环和电感电流内环相结合的双闭环控制策略设计控制器的参数。然后分析并联电阻对级联系统中双向DC/DC输出阻抗的影响。根据Middlebrook阻抗判据，为保证级联系统的稳定性，应满足源变换器输出阻抗Zbc和负载变换器阻抗ZL的阻抗比Tm＝Zbc(s)/ZL(s)的奈奎斯特曲线不包含点(-1，0)。通过改变源级变换器的阻抗使得与负载变换器不相交的方法来改变系统的稳定性。Wherein, the step 3 specifically includes: establishing a small signal model of the bidirectional DC/DC converter through a state space averaging method, and obtaining the output impedance of the bidirectional DC/DC converter. The parameters of the controller will be designed by adopting a double closed-loop control strategy combining the bus voltage outer loop and the inductor current inner loop. Then the effect of parallel resistance on the bidirectional DC/DC output impedance in the cascaded system is analyzed. According to the Middlebrook impedance criterion, in order to ensure the stability of the cascaded system, the impedance ratio T m =Z bc (s)/Z L (s) of the output impedance Z bc of the source converter and the impedance Z L of the load converter should be satisfied. A quist curve does not contain the point (-1, 0). The stability of the system is changed by changing the impedance of the source converter so that it does not intersect with the load converter.

其中，所述步骤4具体包括：通过直流母线侧电压传感器测量直流微电网中直流母线电压udc，通过蓄电池侧电压传感器测量蓄电池输入电压ub，通过蓄电池侧电流传感器测量蓄电池输入电流ib和直流母线侧电流idc。Wherein, the step 4 specifically includes: measuring the DC bus voltage u dc in the DC microgrid by the DC bus side voltage sensor, measuring the battery input voltage u b by the battery side voltage sensor, and measuring the battery input current ib and DC bus side current i dc .

其中，所述步骤5具体包括：通过控制结构的等效变换提出了一种虚拟电阻控制方法来提高系统的稳定性。如图3所示，本控制只是在原本控制的基础上增加一个前馈通路，方法简单可行，实现较为方便。通过直流母线侧电压传感器测量直流微电网中直流母线电压udc乘以系数k(k＝1/RvD)反馈至电压环PI控制器的输出进行比较产生电流环的给定值。Wherein, the step 5 specifically includes: a virtual resistance control method is proposed by the equivalent transformation of the control structure to improve the stability of the system. As shown in Figure 3, this control just adds a feedforward path on the basis of the original control, the method is simple and feasible, and the implementation is relatively convenient. The DC bus voltage u dc in the DC microgrid is measured by the DC bus side voltage sensor, multiplied by the coefficient k (k=1/R v D) and fed back to the output of the voltage loop PI controller for comparison to generate a given value of the current loop.

其中，所述步骤6具体包括：计算得到所述蓄电池DC/DC变换器的占空比D，将控制信号送入所述蓄电池DC/DC变换器的开关管进行PWM调制控制。The step 6 specifically includes: calculating the duty cycle D of the battery DC/DC converter, and sending a control signal to the switch tube of the battery DC/DC converter for PWM modulation control.

本发明的上述实施例所述的一种直流微电网蓄电池双向DC/DC变换器的有源阻尼控制方法，为了验证有源阻尼控制策略的可行性以及理论的正确性，基于Matlab/simulink仿真平台对所提出的方法进行仿真验证。仿真时参数设置如表1所示。In order to verify the feasibility of the active damping control strategy and the correctness of the theory, an active damping control method for a bidirectional DC/DC converter of a DC microgrid battery described in the above embodiments of the present invention is based on the Matlab/simulink simulation platform. The proposed method is verified by simulation. The parameter settings during simulation are shown in Table 1.

表1储能变换器参数Table 1 Parameters of energy storage converter

Figure BDA0003103723270000051
Figure BDA0003103723270000051

为验证基于虚拟电阻的有源阻尼控制方法的影响，分别在只有PI控制的情况下和加入有源阻尼控制的情况进行仿真，初始负荷功率为6kW且每秒增加2kW，仿真时间为3s，仿真结果波形分别如图4、图5所示。可以发现仅PI控制的情况下，随着负荷的增大，直流母线电压发生剧烈振荡，当t＝3s时母线电压出现振荡，系统失去稳定。而在加入有源阻尼控制的母线电压保持稳定。In order to verify the influence of the active damping control method based on virtual resistance, simulations were carried out in the case of only PI control and the case of adding active damping control. The initial load power was 6kW and increased by 2kW per second, and the simulation time was 3s. The resulting waveforms are shown in Figure 4 and Figure 5, respectively. It can be found that in the case of only PI control, as the load increases, the DC bus voltage oscillates violently. When t=3s, the bus voltage oscillates, and the system loses stability. While adding active damping control the bus voltage remains stable.

本发明的上述实施例所述的一种直流微电网蓄电池双向DC/DC变换器的有源阻尼控制方法，无需增加硬件电路、无损耗，将双向DC/DC变换器输出阻抗幅值降为远小于负载变换器的输出阻抗，不改变输出阻抗低频率幅值，不改变系统的潮流分布，提高直流微电网的稳定性。The active damping control method for the bidirectional DC/DC converter of the DC microgrid battery described in the above-mentioned embodiment of the present invention does not require additional hardware circuits and no loss, and reduces the output impedance amplitude of the bidirectional DC/DC converter to a far lower value. It is smaller than the output impedance of the load converter, does not change the low-frequency amplitude of the output impedance, does not change the power flow distribution of the system, and improves the stability of the DC microgrid.

以上所述是本发明的优选实施方式，应当指出，对于本技术领域的普通技术人员来说，在不脱离本发明所述原理的前提下，还可以作出若干改进和润饰，这些改进和润饰也应视为本发明的保护范围。The above are the preferred embodiments of the present invention. It should be pointed out that for those skilled in the art, without departing from the principles of the present invention, several improvements and modifications can be made. It should be regarded as the protection scope of the present invention.

Claims (6)

1. A direct current micro-grid active damping control method is characterized by comprising the following steps:
step 1, building a direct current microgrid model: the direct current microgrid comprises a distributed power generation unit, an energy storage unit and a load unit;
step 2, simplifying a direct-current microgrid model: during modeling, wind and light can be considered as a special type of constant power load with negative output power;
step 3, establishing a small signal model: establishing a small signal model of the bidirectional DC/DC converter by a state space averaging method to obtain the output impedance of the bidirectional DC/DC converter;
step 4, signal measurement: measuring DC bus voltage u in DC micro-grid by DC bus side voltage sensordcMeasuring the input voltage u of the battery by means of a battery-side voltage sensorbMeasuring the input current i of the battery by means of a battery-side current sensorbAnd a direct current bus side current idc；
And 5, active damping control: the method for connecting the virtual resistors in parallel corrects the output impedance of the power supply side, and the resistors are connected in parallel on the side of the bidirectional DC/DC converter of the storage battery, so that the stability of the cascade system can be improved.
2. The active damping control method applied to the direct current microgrid according to claim 1, characterized in that the step 2 specifically comprises:
a maximum power tracking strategy is adopted by wind, light and other intermittent distributed power sources, and for a converter adopting power control, the converter has similar external characteristics with a constant power load, so that the converter can be regarded as a special type of constant power load with negative output power during modeling.
3. The active damping control method applied to the direct current microgrid according to claim 2, characterized in that the step 3 specifically comprises:
the method comprises the steps of establishing a small signal model of the bidirectional DC/DC converter through a state space averaging method to obtain the output impedance of the bidirectional DC/DC converter, analyzing the influence of parallel resistors on the bidirectional DC/DC output impedance in a cascade system, judging the stability of the system, and changing the stability of the system through a method of changing the impedance of a source level converter to enable the impedance of the source level converter to be not intersected with a load converter.
4. The active damping control method applied to the direct current microgrid according to claim 3, characterized in that the step 4 specifically comprises:
measuring DC bus voltage u in DC micro-grid by DC bus side voltage sensordcMeasuring the input voltage u of the battery by means of a battery-side voltage sensorbMeasuring the input current i of the battery by means of a battery-side current sensorbAnd a direct current bus side current idc。
5. The active damping control method applied to the direct current microgrid according to claim 4, characterized in that the step 5 specifically comprises:
a virtual resistance control method is provided through equivalent transformation of a control structure to improve the stability of a system, and the control only adds a feedforward path on the basis of the original control and transmits voltage through a direct current bus sideSensor measuring DC bus voltage u in DC micro-griddcMultiplying by a factor k (k 1/R)vD) And feeding back the output of the voltage loop PI controller for comparison to generate a given value of the current loop.
6. The active damping control method applied to the direct current microgrid according to claim 5, characterized in that the step 6 specifically comprises:
and calculating to obtain the duty ratio D of the storage battery DC/DC converter, and sending a control signal to a switching tube of the storage battery DC/DC converter for PWM modulation control.
CN202110631482.0A 2021-06-07 2021-06-07 Active damping control method for direct-current micro-grid Pending CN113258775A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202110631482.0A CN113258775A (en) 2021-06-07 2021-06-07 Active damping control method for direct-current micro-grid

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202110631482.0A CN113258775A (en) 2021-06-07 2021-06-07 Active damping control method for direct-current micro-grid

Publications (1)

Publication Number Publication Date
CN113258775A true CN113258775A (en) 2021-08-13

Family

ID=77186875

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202110631482.0A Pending CN113258775A (en) 2021-06-07 2021-06-07 Active damping control method for direct-current micro-grid

Country Status (1)

Country Link
CN (1) CN113258775A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117937410A (en) * 2024-01-25 2024-04-26 天津大学 A DC microgrid stabilization control method based on active damping

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20100080028A1 (en) * 2008-09-29 2010-04-01 Rockwell Automation Technologies, Inc. Power conversion system and method for active damping of common mode resonance
CN102005762A (en) * 2010-12-08 2011-04-06 长沙理工大学 Direct current voltage on-line identification method for active filter
CN104868807A (en) * 2015-05-06 2015-08-26 南京航空航天大学 Active damping method of Buck circuit brushless direct current motor control system
CN105098779A (en) * 2014-05-05 2015-11-25 长沙理工大学 Resonance active inhibition method in flexible DC power transmission system
CN106972519A (en) * 2017-04-27 2017-07-21 湖南大学 The active damping control device and method of DC transmission system DC side resonance
CN111355362A (en) * 2020-03-05 2020-06-30 中国地质大学（武汉） FOPI parameter design method of capacitive current FOPI positive feedback active damping strategy
CN111490684A (en) * 2020-05-19 2020-08-04 湘潭大学 Network side power factor and harmonic suppression strategy of isolated AC-DC matrix converter
CN112217225A (en) * 2019-07-11 2021-01-12 华北电力大学（保定） Self-adaptive virtual resistance-capacitance control method for direct-current micro-grid
CN112242699A (en) * 2019-07-18 2021-01-19 华北电力大学（保定） Improved adaptive active damping control method for isolated DC microgrid

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20100080028A1 (en) * 2008-09-29 2010-04-01 Rockwell Automation Technologies, Inc. Power conversion system and method for active damping of common mode resonance
CN102005762A (en) * 2010-12-08 2011-04-06 长沙理工大学 Direct current voltage on-line identification method for active filter
CN105098779A (en) * 2014-05-05 2015-11-25 长沙理工大学 Resonance active inhibition method in flexible DC power transmission system
CN104868807A (en) * 2015-05-06 2015-08-26 南京航空航天大学 Active damping method of Buck circuit brushless direct current motor control system
CN106972519A (en) * 2017-04-27 2017-07-21 湖南大学 The active damping control device and method of DC transmission system DC side resonance
CN112217225A (en) * 2019-07-11 2021-01-12 华北电力大学（保定） Self-adaptive virtual resistance-capacitance control method for direct-current micro-grid
CN112242699A (en) * 2019-07-18 2021-01-19 华北电力大学（保定） Improved adaptive active damping control method for isolated DC microgrid
CN111355362A (en) * 2020-03-05 2020-06-30 中国地质大学（武汉） FOPI parameter design method of capacitive current FOPI positive feedback active damping strategy
CN111490684A (en) * 2020-05-19 2020-08-04 湘潭大学 Network side power factor and harmonic suppression strategy of isolated AC-DC matrix converter

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
朱晓荣，等: "直流微电网的稳定性分析及有源阻尼控制研究", 《高电压技术》 *
贾鹏宇: "高性能直流变换器系统稳定性问题研究", 《中国优秀博硕士学位论文全文数据库(博士) 工程科技Ⅱ辑》 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117937410A (en) * 2024-01-25 2024-04-26 天津大学 A DC microgrid stabilization control method based on active damping

Similar Documents

Publication Publication Date Title
CN108616141B (en) Power nonlinear control method of LCL grid-connected inverter in microgrid
CN101950983A (en) Two-stage photovoltaic grid-connected control system based on combination of pole allocation and repetitive control
CN107230983A (en) A kind of electric power spring application system and its control method based on Power Control
CN105809265A (en) Capacity configuration method of power distribution network flexible interconnection device comprising distributed renewable energy sources
CN102074952A (en) Independent micro-grid system
CN103956778A (en) Micro-grid system and networking method based on phase angle droop control
CN106410839A (en) Active and reactive current coordination control-based photovoltaic grid-connected inverter control method
CN110086200A (en) The control method for coordinating of series-parallel micro-capacitance sensor is mixed under a kind of island mode
CN103606957A (en) Design for multifunctional photovoltaic grid-connected control method
CN111611696A (en) Nonlinear Modeling Methods for Microgrid Systems
CN107579514A (en) A wind-solar-storage DC power system and control method for offshore platforms
CN102751720A (en) Flexible high-voltage direct-current (HVDC) load flow computational model and computational method thereof
CN105720573A (en) Actually-measured data based modeling method for active power and reactive power control system of wind-light power storage station
CN107910889A (en) A kind of grid-connected control method of photovoltaic micro
CN104868773B (en) Single-phase grid-connected inverter control device based on Lyapunov function of states
CN110572067A (en) An island energy storage type power unit series microgrid structure and control method
CN118572726A (en) Oscillation suppression method and system for network-structured flexible direct current transmission system
CN112003319B (en) A dual current feedback control method applied to a bidirectional grid-connected converter
CN110460056A (en) Coordinated control method of series compensation link and AC-DC bus interface converter
CN113258775A (en) Active damping control method for direct-current micro-grid
Mu et al. Transient fault current calculation method of photovoltaic grid-connected system considering the dynamic response of phase-locked loop
CN110429658B (en) Load virtual synchronous machine distributed cooperative control method based on consistency
Zhao et al. Reactive power compensation control of PV systems for improved power transfer capability in weak grid
CN108199406A (en) Microgrid control system based on distributed generation resource
CN107910888A (en) A kind of MPPT grid-connected control methods for photovoltaic series connection micro-capacitance sensor

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
WD01 Invention patent application deemed withdrawn after publication

Application publication date: 20210813

WD01 Invention patent application deemed withdrawn after publication