CN104935015B

CN104935015B - Energy-storage system based on virtual synchronous inversion control

Info

Publication number: CN104935015B
Application number: CN201510362686.3A
Authority: CN
Inventors: 计长安; 李伟; 杭丽君; 罗亚桥; 冯琳; 洪伟; 李国杰; 徐斌; 朱明琳; 谢毓广
Original assignee: Electric Power Research Institute of State Grid Anhui Electric Power Co Ltd; Shanghai Jiao Tong University; State Grid Corp of China SGCC
Current assignee: Electric Power Research Institute of State Grid Anhui Electric Power Co Ltd; Shanghai Jiao Tong University; State Grid Corp of China SGCC
Priority date: 2015-07-23
Filing date: 2015-07-23
Publication date: 2016-12-21
Anticipated expiration: 2035-07-23
Also published as: CN104935015A

Abstract

The invention relates to an energy storage system based on a virtual synchronous inverter technology, comprising a battery, a DC/DC converter, a DC/AC converter, a transformer, an AC grid, a first controller and a second controller. The invention adopts the virtual synchronous motor control technology, so that the external characteristics of the AC interface of the energy storage device with the power electronic system can be equivalent to the characteristics of the synchronous motor, thereby improving the inertia and damping characteristics of the power electronic energy storage system and enhancing the stability of the power system sex.

Description

Energy storage system based on virtual synchronous inverter control

技术领域technical field

本发明涉及智能电网，特别是一种基于虚拟同步逆变控制的储能系统。The invention relates to a smart grid, in particular to an energy storage system based on virtual synchronous inverter control.

背景技术Background technique

因为电力电子装置几乎没有转动惯量和阻尼特性，所以从两种角度考虑储能系统充放电的问题。Because power electronic devices have almost no moment of inertia and damping characteristics, the problem of charging and discharging the energy storage system is considered from two perspectives.

从电网的角度考虑，建立并完善一种对新能源发电更加友好的电网形式——智能电网，能够很好地解决新能源发电的问题。智能电网最主要的两个特征就是智能化和大规模利用可再生能源。未来的智能电网中，交流电网作为电力系统的主要输电方式，直流输电作为交流输电重要的有益补充。相比于交流电网，直流电网对新能源发电更加友好。在小型的分布式发电(主要指风力发电和光伏发电)集中的地方可以建立小型的直流配电网，最终统一逆变后并入大型交流输电网络。由于大规模新能源设备的接入，储能设备也是未来智能电网不可或缺的必要设备。建设智能电网是解决新能源发电并网的一项根本措施。From the perspective of the power grid, establishing and improving a form of power grid that is more friendly to new energy power generation—smart grid can well solve the problem of new energy power generation. The two main features of the smart grid are intelligence and large-scale utilization of renewable energy. In the future smart grid, the AC grid is the main transmission mode of the power system, and the DC transmission is an important and beneficial supplement to the AC transmission. Compared with the AC grid, the DC grid is more friendly to new energy power generation. In places where small-scale distributed power generation (mainly referring to wind power and photovoltaic power generation) is concentrated, a small-scale DC distribution network can be established, and finally integrated into a large-scale AC transmission network after unified inversion. Due to the access of large-scale new energy equipment, energy storage equipment is also an indispensable and necessary equipment for future smart grids. Building a smart grid is a fundamental measure to solve the grid connection of new energy power generation.

从逆变器的角度考虑，交流电网的改造和发展出现了另一种思路。传统大电网的发电装置(火力发电、水力发电等)几乎都是通过同步发电机发电，如果配网中的逆变器从网侧看去能够呈现出同步发电机的运行特性，那么就能够与传统电网良好兼容。为此，需要对逆变器进行改造，使其从网侧看去呈现同步发电机的特性，从而增加交流电网的稳定性。From the perspective of the inverter, there is another way of thinking for the transformation and development of the AC power grid. The power generation devices (thermal power generation, hydropower generation, etc.) of the traditional large power grid are almost all generated by synchronous generators. If the inverter in the distribution network can show the operating characteristics of synchronous generators from the grid side, then it can be compared with The traditional grid is well compatible. For this reason, the inverter needs to be modified so that it can appear as a synchronous generator from the grid side, thereby increasing the stability of the AC grid.

基于储能系统的虚拟同步逆变控制方法，根据同步发电机的电磁惯性，对逆变器进行控制，更能反映出同步发电机的特性。控制器中模拟了同步发电机的电磁特性、转子惯性、一次调频及励磁调压特性，从外特性上看更能模拟同步发电机的特性，且由于无功、有功控制部分存在积分环节，可实现无功、有功的无差控制，并能大大改善系统稳定性。The virtual synchronous inverter control method based on the energy storage system controls the inverter according to the electromagnetic inertia of the synchronous generator, which can better reflect the characteristics of the synchronous generator. The controller simulates the electromagnetic characteristics, rotor inertia, primary frequency regulation and excitation voltage regulation characteristics of the synchronous generator. From the external characteristics, it can better simulate the characteristics of the synchronous generator, and because there is an integral link in the reactive power and active power control part, it can be Realize the non-difference control of reactive power and active power, and can greatly improve the system stability.

发明内容Contents of the invention

本发明的目的在于提供一种基于虚拟同步逆变控制的储能系统，该系统在电池充电时，逆变器采用虚拟同步逆变技术的控制策略，可提高系统的惯性和阻尼特性，增强系统的稳定性。The purpose of the present invention is to provide an energy storage system based on virtual synchronous inverter control. When the system is charging the battery, the inverter adopts the control strategy of virtual synchronous inverter technology, which can improve the inertia and damping characteristics of the system and enhance the system stability.

本发明的技术解决方案如下：Technical solution of the present invention is as follows:

一种基于虚拟同步逆变控制的储能系统，其特点在于，包含电池、DC/DC变换器、DC/AC变换器、变压器、交流电网、第一控制器和第二控制器；An energy storage system based on virtual synchronous inverter control, which is characterized in that it includes a battery, a DC/DC converter, a DC/AC converter, a transformer, an AC grid, a first controller, and a second controller;

所述的电池与DC/DC变换器的输入端相连，所述的DC/DC变换器的输出端与所述的DC/AC变换器的输入端相连，该DC/AC变换器的输出端和所述的变压器的低压输入端相连，所述的变压器的高压输出端与交流电网相连；The battery is connected to the input end of the DC/DC converter, the output end of the DC/DC converter is connected to the input end of the DC/AC converter, the output end of the DC/AC converter is connected to the The low-voltage input end of the transformer is connected, and the high-voltage output end of the transformer is connected to the AC grid;

所述的第一控制器的输出端与所述的DC/DC变换器的控制端相连，第一控制器的输入端与DC/DC变换器的输出端相连，所述的第二控制器的输出端与DC/AC变换器的控制端相连，第二控制器的输入端与所述的DC/AC变换器的输出端相连；The output terminal of the first controller is connected to the control terminal of the DC/DC converter, the input terminal of the first controller is connected to the output terminal of the DC/DC converter, and the output terminal of the second controller is The output terminal is connected to the control terminal of the DC/AC converter, and the input terminal of the second controller is connected to the output terminal of the DC/AC converter;

所述的第一控制器包括第一比较器和第一PI控制器，该第一比较器的输出端接第一PI控制器的输入端；The first controller includes a first comparator and a first PI controller, the output of the first comparator is connected to the input of the first PI controller;

所述的第二控制器包括虚拟同步逆变控制、功率控制、电流控制、电压坐标转换模块、电流坐标转换模块和逆坐标转换模块六部分，所述的虚拟同步逆变控制部分包括机械部分、励磁系统、角度转换模块和电气部分；The second controller includes six parts: virtual synchronous inverter control, power control, current control, voltage coordinate conversion module, current coordinate conversion module and inverse coordinate conversion module. The virtual synchronous inverter control part includes mechanical parts, Excitation system, angle conversion module and electrical part;

所述的机械部分输出端分别接所述的角度转换模块的输入端和所述的逆坐标转换模块的输入端，所述的角度转换模块的输出端分别接所述的电压坐标转换模块的输入端和电流坐标转换模块的输入端，所述的电压坐标转换模块的输出端接所述的电气部分的输入端，所述的励磁系统的输出端接所述的电气部分的输入端，所述的电气部分的输出端接所述电流控制的输入端，所述的功率控制的输出端接所述的电流控制的输入端，所述的电流控制的输出端接所述的逆坐标转换模块的输入端；The output ends of the mechanical parts are respectively connected to the input ends of the angle conversion module and the input ends of the inverse coordinate conversion module, and the output ends of the angle conversion module are respectively connected to the input of the voltage coordinate conversion module terminal and the input terminal of the current coordinate conversion module, the output terminal of the voltage coordinate conversion module is connected to the input terminal of the electrical part, the output terminal of the excitation system is connected to the input terminal of the electrical part, and the The output terminal of the electrical part is connected to the input terminal of the current control, the output terminal of the power control is connected to the input terminal of the current control, and the output terminal of the current control is connected to the inverse coordinate transformation module. input terminal;

所述的机械部分包括依次连接的第二比较器、第三比较器、虚拟转子惯性环节、第一加法器和第一积分器，所述的虚拟转子惯性环节的输出端经调差反馈环节接所述的第二比较器的第二输入端；The mechanical part includes a second comparator, a third comparator, a virtual rotor inertial link, a first adder and a first integrator connected in sequence, and the output end of the virtual rotor inertial link is connected via a differential feedback link. the second input terminal of the second comparator;

所述的励磁系统包括第四比较器、虚拟励磁器和第一补偿器，所述的虚拟励磁器的输出端经所述的第一补偿器接第四比较器的第二输入端；The excitation system includes a fourth comparator, a dummy exciter and a first compensator, the output end of the dummy exciter is connected to the second input end of the fourth comparator through the first compensator;

所述的功率控制部分包括第五比较器和第二PI控制器、第六比较器和第三PI控制器；The power control part includes a fifth comparator and a second PI controller, a sixth comparator and a third PI controller;

所述的电流控制部分包括d轴分量控制和q轴分量控制，所述的d轴分量控制包括第二加法器、第七比较器和第四PI控制器，所述的q轴分量控制包括第三加法器、第八比较器和第五PI控制器。The current control part includes a d-axis component control and a q-axis component control, the d-axis component control includes a second adder, a seventh comparator and a fourth PI controller, and the q-axis component control includes a first Three adders, eighth comparator and fifth PI controller.

所述的第一控制器和第二控制器为数字信号处理器、单片机或计算机。The first controller and the second controller are digital signal processors, single-chip microcomputers or computers.

所述的DC/DC变换器是大功率、宽输出电压范围的直流变换器。The DC/DC converter is a DC converter with high power and wide output voltage range.

所述的DC/AC变换器是采用虚拟同步逆变控制和传统功率控制相结合的综合控制算法的直流变交流的变换器，实现从网侧看将整个储能系统等效为一台同步发电机的目的，自适应地响应电网的电压和频率扰动，增强系统的惯性特性和阻尼特性。The DC/AC converter is a DC-to-AC converter using a comprehensive control algorithm combining virtual synchronous inverter control and traditional power control, realizing that the entire energy storage system is equivalent to a synchronous power generation system viewed from the grid side The purpose of the machine is to adaptively respond to the voltage and frequency disturbance of the power grid, and to enhance the inertia and damping characteristics of the system.

利用所述的基于虚拟同步逆变控制的储能系统的调节方法，其特点在于，该方法包括如下内容和步骤：Using the method for regulating an energy storage system based on virtual synchronous inverter control is characterized in that the method includes the following content and steps:

1)初始化，在该储能系统中由操作员根据系统要求设定以下参数值：1) Initialization. In the energy storage system, the operator sets the following parameter values according to the system requirements:

DC/AC变换器的直流母线电压参考值 DC bus voltage reference value of DC/AC converter

储能系统的电磁功率参考值P_ref；The electromagnetic power reference value P _ref of the energy storage system;

储能系统的无功功率参考值Q_ref；The reactive power reference value Q _ref of the energy storage system;

设定调差系数R为30-50之间、惯性常数M为1-20之间、负荷-阻尼常数D为1％或2％；Set the adjustment coefficient R to be between 30-50, the inertia constant M to be between 1-20, and the load-damping constant D to be 1% or 2%;

设定虚拟转子x_q和定子的阻抗x_d均为1-10之间；Set virtual rotor x _q and stator impedance x _d both between 1-10;

交流侧电压参考值U_ref，标么值设为1；AC side voltage reference value U _ref , the unit value is set to 1;

设定励磁系统的第一补偿器的增益K_f和时间常数T_f为0-1之间，励磁系统的增益K_a在100-500之间，励磁系统的的时间常数T_e在0-1之间，励磁电压幅值的上限E_fmax在0-15之间，励磁电压幅值的下限E_fmin＝-E_fmax；Set the gain K _f and time constant T _f of the first compensator of the excitation system between 0-1, the gain K _a of the excitation system is between 100-500, and the time constant T _e of the excitation system is between 0-1 Between, the upper limit E _fmax of the excitation voltage amplitude is between 0-15, the lower limit E _fmin =-E _fmax of the excitation voltage amplitude;

设定电气部分的虚拟转子暂态阻抗x′_d的取值范围在0.1-0.5之间，定子的暂态阻抗x′_q的取值范围在0.3-1之间，d轴的暂态开路时间常数T′_do的取值范围在1.5-10之间，q轴的暂态开路时间常数T′_qo的取值范围在0.5-2.0之间；Set the value range of the virtual rotor transient impedance x′ _d of the electrical part between 0.1-0.5, the value range of the stator’s transient impedance x′ _q between 0.3-1, and the transient open circuit time of the d-axis The value range of the constant T′ _do is between 1.5-10, and the value range of the transient open circuit time constant T′ _qo of the q axis is between 0.5-2.0;

第一PI控制器的控制系数为k_p1和k_i1，0<k_p1<1000，0<k_i1<1000；The control coefficients of the first PI controller are k _p1 and k _i1 , 0<k _p1 <1000, 0<k _i1 <1000;

第二PI控制器的控制系数为k_p2和k_i2，0<k_p2<1000，0<k_i2<1000；The control coefficients of the second PI controller are k _p2 and k _i2 , 0<k _p2 <1000, 0<k _i2 <1000;

第三PI控制器的控制系数为k_p3和k_i3，0<k_p3<1000，0<k_i3<1000；The control coefficients of the third PI controller are k _p3 and k _i3 , 0<k _p3 <1000, 0<k _i3 <1000;

第四PI控制器的控制系数为k_p4和k_i4，0<k_p4<1000，0<k_i4<1000；The control coefficients of the fourth PI controller are k _p4 and k _i4 , 0<k _p4 <1000, 0<k _i4 <1000;

第五PI控制器的控制系数为k_p5和k_i5，0<k_p5<1000，0<k_i5<1000；The control coefficients of the fifth PI controller are k _p5 and k _i5 , 0<k _p5 <1000, 0<k _i5 <1000;

采用霍尔传感器对直流侧电压、交流侧电压和电流进行采样，得到DC/DC变换器(2)的输出端电压U_dc，单位为标么值，以及电网侧三相电压e_a，e_b，e_c和电网侧三相电流i_a，i_b，i_c；The Hall sensor is used to sample the DC side voltage, AC side voltage and current to obtain the output terminal voltage U _dc of the DC/DC converter (2), the unit is per unit value, and the three-phase voltage e _a , e _b of the grid side , e _c and grid side three-phase current i _a , i _b , i _c ;

2)、第一控制器按以下步骤执行：2), the first controller executes according to the following steps:

21)、第一比较器计算第一PI控制器的输入值： 21), the first comparator calculates the input value of the first PI controller:

22)、第一PI控制器在接收到上述第一比较器的输出后进行计算，输出相应的控制量： 22), the first PI controller calculates after receiving the output of the above-mentioned first comparator, and outputs the corresponding control quantity:

3)第二控制器(7)的虚拟同步逆变控制的机械部分按以下步骤执行：3) The mechanical part of the virtual synchronous inverter control of the second controller (7) is executed in the following steps:

31)、通过第二比较器按下列公式计算虚拟机械功率P_m：31). Calculate the virtual mechanical power P _m through the second comparator according to the following formula:

${P P}_{m m} = = {P P}_{r r e e f f} - - \frac{11}{R R} Δ Δ ω ω,,$

其中，P_ref是设定的电磁功率参考值，R为调差系数，Δω为虚拟转子角度偏移量为虚拟转子惯性环节的输出量，M为虚拟转子惯性环节中的惯性常数，D为虚拟转子惯性环节中的负荷-阻尼常数，s为复频率，Δω的初始值设为零；Among them, P _ref is the set electromagnetic power reference value, R is the adjustment coefficient, Δω is the virtual rotor angle offset is the output of the virtual rotor inertia link, M is the inertia constant in the virtual rotor inertia link, D is the load-damping constant in the virtual rotor inertia link, s is the complex frequency, and the initial value of Δω is set to zero;

32)、通过第三比较器计算机械部分的虚拟加速功率P_a：32). Calculate the virtual acceleration power P _a of the mechanical part through the third comparator:

P_a＝P_m-P_e，其中P_e为机械部分的电磁功率，P_e＝e_ai_a+e_bi_b+e_ci_c；P _a =P _m -P _e , where P _e is the electromagnetic power of the mechanical part, P _e =e _a i _a +e _{bi b} ₊ e _c i _c ;

33)、通过第一加法器计算角速度为：ω＝ω₀+Δω，ω₀为角速度的初始值，当电网频率为50Hz，则ω₀＝2×π×50＝314rad/s；33), the angular velocity calculated by the first adder is: ω=ω ₀ +Δω, ω ₀ is the initial value of the angular velocity, when the grid frequency is 50Hz, then ω ₀ =2×π×50=314rad/s;

34)、通过第一积分器计算同步角度：θ＝∫ω；θ为角度转换模块的输入；34), calculate the synchronization angle by the first integrator: θ=∫ω; θ is the input of the angle conversion module;

35)、通过角度转换模块进行角度补偿，公式如下：35), through the angle conversion module to perform angle compensation, the formula is as follows:

$t t a a n no (({θ θ}_{00})) = = \frac{{x x}_{q q} I I}{{e e}_{g g}}$

${θ θ}^{' '} = = θ θ - - ((\frac{π π}{22} - - {θ θ}_{00}))$

其中，θ′为锁相角度；I为电网电流幅值；e_g为电网电压幅值；x_q为虚拟转子阻抗；Among them, θ' is the phase-locking angle; I is the grid current amplitude; e _g is the grid voltage amplitude; x _q is the virtual rotor impedance;

4)、第二控制器虚拟同步逆变控制的励磁系统按以下步骤执行：4), the excitation system controlled by the virtual synchronous inverter of the second controller is executed according to the following steps:

41)、通过第四比较器计算虚拟励磁器的输入量U_t，公式如下：41) Calculate the input quantity U _t of the virtual exciter through the fourth comparator, the formula is as follows:

U_t＝U_ref-U_x U _t =U _ref -U _x

其中：U_ref为设定的交流侧电压值，K_f和T_f为第一补偿器的增益和时间常数；U_x为第一补偿器的输出；Among them: U _ref is the set AC side voltage value, K _f and T _f are the gain and time constant of the first compensator; U _x is the output of the first compensator;

42)、通过虚拟励磁器计算电气部分的输入虚拟励磁电压E_f，公式如下：42). Calculate the input virtual excitation voltage E _f of the electrical part through the virtual exciter, the formula is as follows:

${E E.}_{f f} = = \frac{{K K}_{a a}}{{T T}_{e e} s the s + + 11} {U u}_{t t},,$

其中：K_a和T_e分别为虚拟励磁器的增益和时间常数，E_fmax和E_fmin分别为虚拟励磁器的电压幅值的上限和下限；Among them: K _a and T _e are the gain and time constant of the virtual exciter, respectively, and E _fmax and E _fmin are the upper limit and lower limit of the voltage amplitude of the virtual exciter, respectively;

43)、通过第一补偿器计算U_x,，公式如下：43) Calculate U _x through the first compensator, the formula is as follows:

${U u}_{x x} = = \frac{{sK k}_{f f}}{{T T}_{f f} s the s + + 11} {E E.}_{f f} . .$

5)、电压坐标变换模块和电流坐标变换模块按以下步骤执行：5), the voltage coordinate transformation module and the current coordinate transformation module are executed according to the following steps:

51)、由e_a、e_b和e_c经电压坐标变换模块计算出电网电压d-q分量U_d和U_q，公式如下：51). Calculate the grid voltage dq components U _d and U _q from e _a , e _b and e _c through the voltage coordinate transformation module, the formula is as follows:

$[\begin{matrix} {U u}_{d d} \\ {U u}_{q q} \end{matrix}] = = \frac{\sqrt{22}}{\sqrt{33}} [\begin{matrix} c c o o s the s θ θ & c c o o s the s ((θ θ - - \frac{22}{33} π π)) & c c o o s the s ((θ θ + + \frac{22}{33} π π \\ - - s the s i i n no θ θ & - - sin sin ((θ θ - - \frac{22}{33} π π)) & - - sin sin ((θ θ + + \frac{22}{33} π π)) \end{matrix}] [\begin{matrix} {e e}_{a a} \\ {e e}_{b b} \\ {e e}_{c c} \end{matrix}]$

52)、由i_a、i_b和i_c经电流坐标变换模块计算出电网电压d-q分量i_d和i_q，公式如下：52). Calculate grid voltage dq components i _d and i _q from i _a , i _b and i _c through the current coordinate transformation module, the formula is as follows:

$[\begin{matrix} {i i}_{d d} \\ {i i}_{q q} \end{matrix}] = = \frac{\sqrt{22}}{\sqrt{33}} [\begin{matrix} c c o o s the s θ θ & c c o o s the s ((θ θ - - \frac{22}{33} π π)) & c c o o s the s ((θ θ + + \frac{22}{33} π π \\ - - s the s i i n no θ θ & - - sin sin ((θ θ - - \frac{22}{33} π π)) & - - sin sin ((θ θ + + \frac{22}{33} π π)) \end{matrix}] [\begin{matrix} {i i}_{a a} \\ {i i}_{b b} \\ {i i}_{c c} \end{matrix}]$

6)、第二控制器虚拟同步逆变控制的电气部分按以下步骤执行：6), the electrical part of the virtual synchronous inverter control of the second controller is executed according to the following steps:

61)、计算电流参考I_dref1和I_qref1，公式如下：61), calculate the current reference I _dref1 and I _qref1 , the formula is as follows:

${I I}_{d d r r e e f f 11} = = \frac{{E E.}_{f f} - - (({T T}_{d d 00}^{' '} s the s + + 11)) {U u}_{q q}}{{x x}_{d d}^{' '} {T T}_{d d 00}^{' '} s the s + + {x x}_{d d}}$

${I I}_{q q r r e e f f 11} = = \frac{(({T T}_{q q 00}^{' '} s the s + + 11)) {U u}_{d d}}{{x x}_{q q}^{' '} {T T}_{q q 00}^{' '} s the s + + {x x}_{q q}}$

其中：U_d和U_q是电网电压的d-q分量；I_dref1和I_qref1是所述的DC/AC变换器(3)输出电流的虚拟定子电流部分，E_f是虚拟励磁电压；Wherein: U _d and U _q are the dq components of the grid voltage; I _dref1 and I _qref1 are the virtual stator current part of the output current of the DC/AC converter (3), and E _f is the virtual excitation voltage;

7)、第二控制器功率控制部分按以下步骤执行：7), the power control part of the second controller is executed according to the following steps:

71)、通过第五比较器计算出第二PI控制器的输入：P_ref-P_e；71), calculate the input of the second PI controller through the fifth comparator: _{Pre ref} -P _e ;

72)、第二PI控制器在接收到上述第五比较器的输出后进行控制运算，输出相应的控制量I_dref2：I_dref2＝k_p2(P_ref-P_e)+k_i2∫(P_ref-P_e)dt；即为电流控制部分的输入；72), the second PI controller performs control operation after receiving the output of the fifth comparator, and outputs the corresponding control quantity I _dref2 : I _dref2 =k _p2 (P _ref -P _e )+k _i2 ∫(P _ref -P _e )dt; that is, the input of the current control part;

73)、通过第六比较器计算出第三PI控制器的输入：Q_ref-Q_e；73), calculate the input of the third PI controller through the sixth comparator: Q _ref -Q _e ;

74)、第三PI控制器在接收到上述第六比较器的输出后进行控制运算，输出相应的控制量I_qref2：74), the third PI controller performs the control operation after receiving the output of the sixth comparator, and outputs the corresponding control quantity I _qref2 :

I_qref2＝k_p3(Q_ref-Q_e)+k_i3∫(Q_ref-Q_e)dt；即为电流控制部分的输入；I _qref2 ＝k _p3 (Q _ref -Q _e )+k _i3 ∫(Q _ref -Q _e )dt; it is the input of the current control part;

8)、第二控制器(7)电流控制部分的d轴分量控制按以下步骤执行：8), the d-axis component control of the second controller (7) current control part is carried out according to the following steps:

81)、计算出d轴电流参考值I_dref，公式如下：81), calculate the d-axis current reference value I _dref , the formula is as follows:

I_dref＝I_dref1+I_dref2；I _dref =I _dref1 +I _dref2 ;

82)、通过第七比较器计算出第四个PI控制器的输入：I_dref-I_d；I_d为三相电流d轴分量，由i_a、i_b和i_c经坐标变换输出；82), the input of the fourth PI controller is calculated by the seventh comparator: I _dref -I _d ; I _d is the _d -axis component of the three-phase current, which is output by ia, _ib and _ic through coordinate transformation;

83)、第四PI控制器在接收到上述第七个比较器的输出后进行控制运算，输出相应得控制量U_dref：U_dref＝k_p4(I_dref-I_d)+k_i4∫(I_dref-I_d)dt；83), the fourth PI controller performs the control calculation after receiving the output of the seventh comparator, and outputs the corresponding control variable U _dref : U _dref =k _p4 (I _dref -I _d )+k _i4 ∫(I _dref -I _d )dt;

9)、第二控制器电流控制部分的q轴分量控制按以下步骤执行：9), the q-axis component control of the current control part of the second controller is performed according to the following steps:

91)、计算出q轴电流参考值I_qref，公式如下：91), calculate the q-axis current reference value I _qref , the formula is as follows:

I_qref＝I_qref1+I_qref2；I _qref = I _qref1 + I _qref2 ;

92)、通过第八比较器计算出第五PI控制器的输入：I_qref-I_q；I_q为三相电流q轴分量，由i_a、i_b和i_c经坐标变换输出；92), calculate the input of the fifth PI controller through the eighth comparator: I _qref -I _q ; I _q is the _q -axis component of the three-phase current, which is output by ia, _ib and _ic through coordinate transformation;

93)、第五PI控制器在接收到上述第八比较器的输出后进行控制运算，输出相应得控制量U_qref：U_qref＝k_p5(I_qref-I_q)+k_i5∫(I_qref-I_q)dt；93), the fifth PI controller performs control operation after receiving the output of the eighth comparator, and outputs the corresponding control quantity U _qref : U _qref =k _p5 (I _qref -I _q )+k _i5 ∫(I _qref -I _q )dt;

10)、第二控制器输出量：10), the output of the second controller:

101)、将所获得的U_dref和U_qref经逆坐标变换模块变换，得到U_aref、U_bref和U_cref三个调制波，将这三个量作为控制信号与载波比较，获得DC/AC变换器(3)的控制信号，公式如下：101), transform the obtained U _dref and U _qref through the inverse coordinate transformation module to obtain three modulation waves U _aref , U _bref and U _cref , use these three quantities as control signals and compare them with the carrier to obtain DC/AC conversion The control signal of device (3), the formula is as follows:

$[\begin{matrix} {U u}_{a a r r e e f f} \\ {U u}_{b b r r e e f f} \\ {U u}_{c c r r e e f f} \end{matrix}] = = \frac{\sqrt{22}}{\sqrt{33}} [\begin{matrix} c c o o s the s θ θ & - - s the s i i n no θ θ \\ c c o o s the s ((θ θ - - \frac{22}{33} π π)) & - - sin sin ((θ θ - - \frac{22}{33} π π)) \\ c c o o s the s ((θ θ + + \frac{22}{33} π π)) & - - sin sin ((θ θ + + \frac{22}{33} π π)) \end{matrix}] [\begin{matrix} {U u}_{d d r r e e f f} \\ {U u}_{q q r r e e f f} \end{matrix}] . .$

本发明的技术效果如下：Technical effect of the present invention is as follows:

本发明系统中，和电网侧连接的DC/AC逆变器采用虚拟同步逆变技术的控制方法，给电网必要的频率支撑和电压支撑，提高系统的稳定性。其特点如下：In the system of the present invention, the DC/AC inverter connected to the grid side adopts the control method of the virtual synchronous inverter technology to provide the necessary frequency support and voltage support for the grid and improve the stability of the system. Its characteristics are as follows:

1、由于电力电子系统交流接口的外特性等效为同步发电机特性，使得蓄电池充放电接口设备可以参与电网交互，给电网电压和频率提供必要的支撑，可提高电网稳定性。1. Since the external characteristics of the AC interface of the power electronic system are equivalent to the characteristics of a synchronous generator, the battery charging and discharging interface equipment can participate in the grid interaction, provide the necessary support for the grid voltage and frequency, and improve the stability of the grid.

2.采用具有大功率传输能力的、宽输出电压范围的DC/DC变换器，可提高系统的响应速度和控制精度。2. The DC/DC converter with high power transmission capability and wide output voltage range can improve the response speed and control precision of the system.

附图说明Description of drawings

图1是本发明基于虚拟同步逆变技术的储能系统的整体框图。Fig. 1 is an overall block diagram of the energy storage system based on the virtual synchronous inverter technology of the present invention.

图2是虚拟同步逆变控制整体控制框图。Fig. 2 is the overall control block diagram of virtual synchronous inverter control.

图3是机械部分控制框图。Figure 3 is a control block diagram of the mechanical part.

图4是励磁系统控制器框图。Figure 4 is a block diagram of the excitation system controller.

图5是第一控制器控制框图。Fig. 5 is a control block diagram of the first controller.

图6是第二控制器功率控制框图。Fig. 6 is a block diagram of power control of the second controller.

图7是第二控制器电流控制框图。Fig. 7 is a block diagram of the current control of the second controller.

图8是角度转换模块Figure 8 is the angle conversion module

图9是系统控制流程图。Fig. 9 is a flow chart of system control.

具体实施方式detailed description

下面结合实施例和附图对本发明作进一步说明，氮不应以此限制本发明的保护范围。The present invention will be further described below in conjunction with embodiment and accompanying drawing, nitrogen should not limit protection scope of the present invention with this.

请参阅图1，图1为本发明基于虚拟同步逆变技术的储能系统示意图，包含电池1、DC/DC变换器2、DC/AC变换器3、变压器4、交流电网5、第一控制器6和第二控制器7，以下详细介绍各个组成部分：Please refer to Figure 1, Figure 1 is a schematic diagram of the energy storage system based on the virtual synchronous inverter technology of the present invention, including a battery 1, a DC/DC converter 2, a DC/AC converter 3, a transformer 4, an AC grid 5, a first control 6 and the second controller 7, each component is described in detail below:

所述的电池1是为储能系统提供能量存储和能量输出的设备；The battery 1 is a device that provides energy storage and energy output for the energy storage system;

DC/DC变换器2是大功率、宽输出电压范围的变换器；DC/DC converter 2 is a converter with high power and wide output voltage range;

DC/AC变换器3采用虚拟同步逆变技术的控制方法和传统功率控制相结合的综合控制算法，实现从网侧看将整个储能系统等效为一台同步发电机的目的，自适应地响应电网的电压和频率扰动，增强系统的惯性特性和阻尼特性。DC/AC converter 3 adopts a comprehensive control algorithm combining the control method of virtual synchronous inverter technology and traditional power control, realizing the purpose of equivalenting the entire energy storage system to a synchronous generator from the grid side, and adaptively Respond to the voltage and frequency disturbance of the power grid, and enhance the inertia and damping characteristics of the system.

第一控制器6负责DC/DC变换器2的采样、处理、计算及控制等；The first controller 6 is responsible for the sampling, processing, calculation and control of the DC/DC converter 2;

第二控制器7负责数据采样、处理、计算及控制等，对网侧的DC/AC变换器3进行控制。The second controller 7 is responsible for data sampling, processing, calculation and control, etc., and controls the DC/AC converter 3 on the grid side.

所述的电池1与DC/DC变换器2的输入端相连，所述的DC/DC变换器2的输出端与所述的DC/AC变换器3的输入端相连，该DC/AC变换器3的输出端和所述的变压器4的低压输入端相连，所述的变压器4的高压输出端与交流电网5相连；The battery 1 is connected to the input end of the DC/DC converter 2, the output end of the DC/DC converter 2 is connected to the input end of the DC/AC converter 3, and the DC/AC converter The output terminal of 3 is connected with the low-voltage input terminal of the transformer 4, and the high-voltage output terminal of the transformer 4 is connected with the AC grid 5;

所述的第一控制器6的输出端与所述的DC/DC变换器2的控制端相连，第一控制器6的输入端与DC/DC变换器2的输出端相连,，所述的第二控制器7的输出端与DC/AC变换器3的控制端相连，第二控制器7的输入端与所述的DC/AC变换器3的输出端相连。The output end of the first controller 6 is connected to the control end of the DC/DC converter 2, the input end of the first controller 6 is connected to the output end of the DC/DC converter 2, and the The output end of the second controller 7 is connected to the control end of the DC/AC converter 3 , and the input end of the second controller 7 is connected to the output end of the DC/AC converter 3 .

图2为第一控制器6的控制框图，所述的第一控制器6包括第一比较器和第一PI控制器，该第一比较器的输出端接第一PI控制器的输入端。FIG. 2 is a control block diagram of the first controller 6. The first controller 6 includes a first comparator and a first PI controller. The output terminal of the first comparator is connected to the input terminal of the first PI controller.

所述的第二控制器7包括虚拟同步逆变控制、功率控制、电流控制、电压坐标转换模块、电流坐标转换模块和逆坐标转换模块六部分，所述的虚拟同步逆变控制部分包括机械部分、励磁系统、角度转换模块和电气部分；The second controller 7 includes six parts: virtual synchronous inverter control, power control, current control, voltage coordinate conversion module, current coordinate conversion module and inverse coordinate conversion module, and the virtual synchronous inverter control part includes mechanical parts , excitation system, angle conversion module and electrical parts;

图3是虚拟同步逆变控制整体控制框图，图4是机械部分控制框图，图5为虚拟同步逆变控制方法的励磁控制系统，图6为第二控制器7的功率控制框图，图7为第二控制器的电流控制框图，图8为角度转换模块示意图，图9为本发明系统的整体控制流程图。图4、图5、图6和图7都包含在图3中。Fig. 3 is the overall control block diagram of the virtual synchronous inverter control, Fig. 4 is the control block diagram of the mechanical part, Fig. 5 is the excitation control system of the virtual synchronous inverter control method, Fig. 6 is the power control block diagram of the second controller 7, and Fig. 7 is The current control block diagram of the second controller, FIG. 8 is a schematic diagram of the angle conversion module, and FIG. 9 is the overall control flow chart of the system of the present invention. Figures 4, 5, 6 and 7 are all included in Figure 3.

Claims

1. An energy storage system based on virtual synchronous inverter control, characterized in that it comprises a battery (1), a DC/DC converter (2), a DC/AC converter (3), a transformer (4), and an AC grid (5), the first controller (6) and the second controller (7):

The battery (1) is connected to the input end of the DC/DC converter (2), and the output end of the DC/DC converter (2) is connected to the input end of the DC/AC converter (3) connected, the output end of the DC/AC converter (3) is connected to the low-voltage input end of the transformer (4), and the high-voltage output end of the transformer (4) is connected to the AC grid (5);

The output end of the first controller (6) is connected to the control end of the DC/DC converter (2), and the input end of the first controller (6) is connected to the DC/DC converter (2) The output terminal is connected, the output terminal of the second controller (7) is connected with the control terminal of the DC/AC converter (3), the input terminal of the second controller (7) is connected with the DC/AC converter (3) output terminals are connected;

The first controller (6) includes a first comparator and a first PI controller, the output of the first comparator is connected to the input of the first PI controller;

The second controller (7) includes six parts: virtual synchronous inverter control, power control, current control, voltage coordinate conversion module, current coordinate conversion module and inverse coordinate conversion module, and the virtual synchronous inverter control part includes Mechanical part, excitation system, angle conversion module and electrical part;

The output ends of the mechanical parts are respectively connected to the input ends of the angle conversion module and the input ends of the inverse coordinate conversion module, and the output ends of the angle conversion module are respectively connected to the input of the voltage coordinate conversion module terminal and the input terminal of the current coordinate conversion module, the output terminal of the voltage coordinate conversion module is connected to the input terminal of the electrical part, the output terminal of the excitation system is connected to the input terminal of the electrical part, and the The output terminal of the electrical part is connected to the input terminal of the current control, the output terminal of the power control is connected to the input terminal of the current control, and the output terminal of the current control is connected to the inverse coordinate transformation module. input terminal;

The mechanical part includes a second comparator, a third comparator, a virtual rotor inertial link, a first adder and a first integrator connected in sequence, and the output end of the virtual rotor inertial link is connected via a difference adjustment feedback link. the second input terminal of the second comparator;

The excitation system includes a fourth comparator, a dummy exciter and a first compensator, the output end of the dummy exciter is connected to the second input end of the fourth comparator through the first compensator;

The power control part includes a fifth comparator and a second PI controller, a sixth comparator and a third PI controller;

The current control part includes a d-axis component control and a q-axis component control, the d-axis component control includes a second adder, a seventh comparator and a fourth PI controller, and the q-axis component control includes a first Three adders, eighth comparator and fifth PI controller.

2. The energy storage system based on virtual synchronous inverter control according to claim 1, characterized in that, the first controller (6) and the second controller (7) are digital signal processors, single-chip microcomputers or computer.

3. The energy storage system based on virtual synchronous inverter control according to claim 1, characterized in that, the DC/AC converter (3) is a comprehensive system that combines virtual synchronous inverter control and traditional power control The DC-to-AC converter of the control algorithm realizes the purpose of equivalenting the entire energy storage system as a synchronous generator from the grid side, adaptively responds to the voltage and frequency disturbance of the grid, and enhances the inertial and damping characteristics of the system .