CN113904588B - Fluctuating pressure power generation control method and device of power generation-energy storage system - Google Patents

Abstract

The invention discloses a power generation-energy storage systemThe invention relates to a method and a device for controlling the power generation by the fluctuating pressure, which comprises the step of calculating an actually measured power value N _meas Target power value N _ref Obtaining an active power error signal; calculating the actual pressure P _mea Setting a pressure value P _ref Obtaining the difference and an air pressure error signal, and summing the active power error signal and the air pressure error signal to obtain a multivariable control signal; and controlling the working state of a pressure regulating valve between a high-pressure gas system and a gas-liquid mixing system of the power generation-energy storage system in a power generation stage according to a multivariable control signal. The invention can realize the stable control of the power in the power generation process, provides a control method for realizing the constant output of the power generation unit under the pressure fluctuation of the power generation-energy storage system, and provides an important theoretical support and practical basis for improving the flexibility of the power system.

Description

A fluctuating pressure power generation control method and device for a power generation-energy storage system

technical field

The invention relates to a power generation control technology of a power generation-energy storage system, in particular to a fluctuating pressure power generation control method and device for a power generation-energy storage system.

Background technique

With the contradiction between the unconventional development of new energy power generation and the relatively lagging power grid construction becoming more and more obvious, the large-scale wind power/photovoltaic energy connected to the grid with the characteristics of randomness, intermittency, anti-regulation and large output fluctuations has a great impact on the voltage of the system. Stability, transient stability, and frequency stability all have a greater impact, and wind power/photovoltaic energy is difficult to connect to the grid, and it is difficult to accommodate it after grid connection, which seriously restricts the transformation of the energy structure. Conventional hydropower plants and pumped storage power plants have limited role in large-scale new energy storage and energy conversion, and cannot absorb large-scale renewable new energy such as wind power and solar power, and have certain requirements for terrain and geology.

The Chinese patent document with application number 202020451871.6 discloses a power generation-energy storage system including a high-pressure gas system and a gas-liquid mixing system. The high-pressure gas system includes a gas storage container and a gas compression device for supplying gas to the gas storage container. The system includes a gas-liquid mixing container connected with a liquid replenishment circulation system and a hydraulic generator set. The gas storage container and the gas-liquid mixing container are connected through a regulating valve. The power generation-energy storage system can To achieve energy storage and power generation, you can also choose a variety of operating modes. As a new type of power generation system, the power generation-energy storage system has the advantages of clean and pollution-free, flexible layout, and long operating life. It is of great value for large-scale new energy consumption and improving the flexibility of the power system. However, during the power generation process, the liquid volume in the gas-liquid mixing system decreases, and the pressure tends to drop. The high-pressure gas system supplements the gas-liquid mixing system with a pressure regulating valve to try to maintain a stable air pressure. However, the pressure at the output end of the pressure regulating valve is difficult to maintain. Constant value, practice shows that the fluctuation range of the output air pressure of the air pressure regulating valve is not less than 5% compared with the average value of the output air pressure. The fluctuation of air pressure in the gas-liquid mixing system not only seriously affects the stability of the power of the generator set and the safe and stable operation of the unit, but in severe cases will lead to low-frequency oscillation of the power system. Research and engineering practice have important scientific significance and practical value.

Contents of the invention

The technical problem to be solved by the present invention: Aiming at the above-mentioned problems of the prior art, a method and device for fluctuating pressure power generation control of a power generation-energy storage system are provided. The present invention realizes stable control of power generation process power through closed-loop control and control strategy, It can realize the stable control of the power in the power generation process, provides a control method for the power generation-energy storage system to realize the constant power output of the generator set under pressure fluctuations, and provides important theoretical support and practical basis for improving the flexibility of the power system.

In order to solve the problems of the technologies described above, the technical solution adopted in the present invention is:

A method for controlling fluctuating pressure power generation of a power generation-energy storage system, comprising:

1) Calculate the difference between the measured power value N _meas and the target power value N _ref , and obtain the active power error signal according to the difference between the measured power value N _meas and the target power value N _ref ; calculate the actual air pressure P _mea and set the air pressure value P _ref difference, and obtain the air pressure error signal according to the difference between the actual air pressure P _mea and the set air pressure value Pre _ref , and obtain the multivariable control signal by summing the active power error signal and the air pressure error signal;

2) According to the multivariable control control signal, the working state of the air pressure regulating valve between the high-pressure gas system and the gas-liquid mixing system of the power generation-energy storage system is controlled during the power generation stage.

Optionally, the acquisition of the active power error signal according to the difference between the measured power value N _meas and the target power value N _ref refers to inputting the difference between the measured power value N _meas and the target power value N _ref into the active power closed-loop controller to obtain Active power error signal.

Optionally, obtaining the air pressure error signal according to the difference between the actual air pressure P _mea and the set air pressure value _Pref refers to inputting the difference between the actual air pressure P _mea and the set air pressure value _Pref into the air pressure closed-loop controller to obtain active power error signal.

Optionally, the active power closed-loop controller is a PID controller.

Optionally, the air pressure closed-loop controller is a PID controller.

Optionally, step 1) also includes the step of parameter designing the active power closed-loop controller and the air pressure closed-loop controller:

S1) Establish the nonlinear differential equations of the temperature, volume and pressure dynamic change characteristics of the gas control body and the liquid controller in the power generation stage:

S2) Transform the nonlinear differential equations of the temperature, volume, and pressure dynamic change characteristics of the gas control body and the liquid controller in the power generation stage into a transfer function, and solve the active power closed-loop controller and the air pressure closed-loop controller according to the relationship between the transfer function and the PID parameters The PID control parameters.

Optionally, the nonlinear differential equations of the temperature, volume, and pressure dynamic change characteristics of the gas control body and the liquid controller in the power generation stage established in step S1) are:

为状态变量的微分，X为状态变量，U_u为控制向量，f(X,U_u)为状态变量的微分

与状态变量X以及控制向量U_u两者的函数关系，y为输出，g(X)为输出y与状态变量X之间的函数关系，且有：in,

is the differential of the state variable, X is the state variable, U _u is the control vector, f(X,U _u ) is the differential of the state variable

The functional relationship between the state variable X and the control vector U _u , y is the output, g(X) is the functional relationship between the output y and the state variable X, and there are:

X=[T _B,gas ,T _A,gas ,V _B,gas ,m _{A,gas ,} m _B,gas ,T _l ,Z _l ,T _{gas,T ,} T _l,T ] ^T , U _u =[ u ₁ , u ₂ ] ^T

Among them, T _B,gas , T _A,gas are the temperature of gas control body B in the gas-liquid mixing system and gas control body A in the gas-liquid mixing system respectively, V _B,gas is the temperature of gas control body B in the gas-liquid mixing system Volume, m _{A, gas} , m _{B, gas} are the mass of gas control body A in the gas-liquid mixing system and gas control body B in the gas-liquid mixing system respectively, T _l is the liquid temperature of the gas-liquid mixing container, Z _l is the liquid The liquid level of the control body, T _{gas, T} is the temperature of the gas-liquid mixing container wall, T _{l, T} is the temperature of the container wall in contact with the liquid control body, u ₁ , u ₂ are the control variables, and there are:

分别为状态变量x₁～x₈的微分，x₁～x₉分别为状态变量，k为空气比热容的比值，ρ_w为液体控制器的密度，ρ_l为液体控制体的密度ρ_l＝ρ_w，A_l为液体控制体水平面的面积，c_l为液体控制体的比热容，

为液体控制体出口液体温度，y₁、γ₁～γ₄以及γ₈～γ₁₂均为中间变量，T_amb为环境温度；且有：In the above formula,

are the differentials of the state variables x ₁ ~ x ₈ respectively, x ₁ ~ x ₉ are the state variables respectively, k is the ratio of air specific heat capacity, ρ _w is the density of the liquid controller, ρ _l is the density of the liquid control body ρ _l = ρ _w , A _l is the area of the horizontal plane of the liquid control body, c _l is the specific heat capacity of the liquid control body,

is the liquid temperature at the outlet of the liquid control body, y ₁ , γ ₁ ~ γ ₄ and γ ₈ ~ γ ₁₂ are all intermediate variables, T _amb is the ambient temperature; and there are:

m_gas,Tc_T＝γ₈，

ρ_lA_l＝γ₅，h_gas,TA_gas,T＝γ₉，h_oA_o,gas＝γ₁₀，h_{l, T}A_l,T＝γ₁₁，h_gas,lA_l＝γ₁₂，

m _gas,T c _T =γ ₈ ,

ρ _l A _l = γ ₅ , h _{gas, T} A _{gas, T} = γ ₉ , h _o A _{o, gas} = γ ₁₀ , h _{l, T} A _{l, T} = γ ₁₁ , h _{gas, l} A _l = γ ₁₂ ,

为高压气系统内空气控制体A、气液混合系统内空气控制体B之间的交换速率，

为汽液混合容器内液体控制器的质量流出流率，m_gas,T为与空气接触的容器器壁控制体质量，c_T为气液混合容器器壁的比热容，

表示气液混合系统内空气控制体B的空气定容比热容，U为与环境接触器壁的换热系数，A_G为气液混合系统内空气控制体B与气体接触的器壁面积，

表示气液混合系统内空气控制体A的空气定容比热容，R_g为空气气体常数，ρ_w为汽液混合容器内液体控制体的密度，h_gas,T为气体控制体与容壁之间的换热系数，A_gas,T为气体控制体与汽液混合容器器壁接触的面积，h_o为气液混合容器器壁与外部环境之间换热系数，A_o,gas为与气液混合容器内部空气接触的器壁暴露在外部环境的面积，h_l,T为液体与汽液混合容器器壁之间的换热系数，A_l,T为液体控制体与汽液混合容器器壁接触的面积，p_B,gas为气液混合系统内空气控制体B的压力。In the above formula,

is the exchange rate between the air control body A in the high-pressure gas system and the air control body B in the gas-liquid mixing system,

is the mass outflow rate of the liquid controller in the gas-liquid mixing vessel, m _{gas, T} is the mass of the control body on the wall of the vessel in contact with the air, c _T is the specific heat capacity of the wall of the gas-liquid mixing vessel,

Indicates the specific heat capacity of the air at constant volume of the air control body B in the gas-liquid mixing system, U is the heat transfer coefficient with the environment contactor wall, A _G is the wall area of the air control body B in the gas-liquid mixing system in contact with the gas,

Indicates the constant-volume specific heat capacity of the air control body A in the gas-liquid mixing system, R _g is the air gas constant, ρ _w is the density of the liquid control body in the gas-liquid mixing container, h _{gas, T} is the distance between the gas control body and the volume wall The heat transfer coefficient, A _gas,T is the contact area between the gas control body and the gas-liquid mixing container wall, h _o is the heat transfer coefficient between the gas-liquid mixing container wall and the external environment, A _o,gas is the gas-liquid mixing container wall The area of the wall exposed to the external environment where the air in the mixing container is exposed, h _l,T is the heat transfer coefficient between the liquid and the wall of the vapor-liquid mixing container, A _l,T is the liquid control body and the wall of the vapor-liquid mixing container The contact area, p _{B, gas} is the pressure of the air control body B in the gas-liquid mixing system.

Optionally, step S2) includes:

S2.1) According to the current state variable value, the nonlinear differential equation of the temperature, volume and pressure dynamic change characteristics of the gas control body and the liquid controller in the power generation stage is linearized to obtain the linearization equation:

In the above formula, A is the system matrix, B is the input matrix, and C is the output matrix, and there are:

Among them, f is the functional relationship between the differential equation and the state variable X and the control vector U;

S2.2) Transform the linearization equation into the state space equation of the transfer function G(s) of the state variable point X _e at the current moment t shown in the following formula:

G(s)＝C(X _e )(sI-A) ^-1 B(X _e )

In the above formula, I is the identity matrix, and A is the system matrix;

的闭环特征方程根；S2.3) According to the transfer function _Gc (s) of the PID control law shown in the following formula and the transfer function G(s) of the state variable point _Xe at the current moment t, the control system at the current moment t is obtained

The root of the closed-loop characteristic equation;

In the above formula, K _p , K _i , K _d are PID control parameters, and T _1v is the actual differential link time constant;

稳定的闭环特征方程根进行极点配置，建立闭环系统极点与PID参数的关系，从而求得PID控制参数K_p,K_i,K_d。S2.4) to ensure that the control system

The stable closed-loop characteristic equation roots are configured with poles, and the relationship between the closed-loop system poles and PID parameters is established, so as to obtain the PID control parameters K _p , K _i , K _d .

In addition, the present invention also provides a fluctuating pressure power generation control device used in the fluctuating pressure power generation control method of the power generation-energy storage system, including:

The control unit is used to calculate the difference between the measured power value N _meas and the target power value N _ref , and obtain an active power error signal according to the difference between the measured power value N _meas and the target power value N _ref ; calculate the actual air pressure P _mea , set the air pressure value P _ref , and obtain the air pressure error signal according to the difference between the actual air pressure P _mea and the set air pressure value P _ref , and obtain the multivariable control signal by summing the active power error signal and the air pressure error signal;

The valve control module is used to control the working state of the air pressure regulating valve between the high-pressure gas system and the gas-liquid mixing system of the power generation-energy storage system in the power generation stage according to the multivariable control control signal;

The output end of the control unit is connected with the valve control module, and the valve control module is used for connecting with the control end of the air pressure regulating valve between the high-pressure gas system and the gas-liquid mixing system of the power generation-energy storage system.

Optionally, the control unit includes: an active power error calculation unit, used to calculate the difference between the measured power value N _meas and the target power value N _{ref ;} The difference between the value N _ref is used to obtain the active power error signal; the air pressure error calculation unit is used to calculate the difference between the actual air pressure P _mea and the set air pressure value P _ref ; the air pressure closed-loop controller is used to set the air pressure value according to the actual air pressure P _mea The difference between P _ref obtains the air pressure error signal; the summation module is used to sum the active power error signal and the air pressure error signal to obtain a multivariable control control signal; the output terminal of the active power error calculation unit is connected to the active power closed-loop controller The input ends are connected, the output end of the air pressure closed-loop controller is connected with the input end of the air pressure closed-loop controller, the output ends of the active power closed-loop controller and the air pressure closed-loop controller are connected with the input end of the summation module, so The output end of the summation module is connected with the valve control module; the active power closed-loop controller and air pressure closed-loop controller are PID controllers.

Compared with the prior art, the present invention has the following advantages: the present invention includes calculating the difference between the measured power value N _meas and the target power value N _ref and obtaining the active power error signal; calculating the actual air pressure P _mea , setting the air pressure value P _ref difference and obtain the air pressure error signal, the active power error signal and the air pressure error signal are summed to obtain the multivariable control control signal; according to the multivariable control control signal, the high-pressure gas system and the gas-liquid mixing system of the power generation-energy storage system are controlled. The working state of the air pressure regulating valve in the power generation stage. The present invention aims at the problem that the pressure fluctuation in the gas-liquid mixing system in the joint power generation stage of the high-pressure gas system and the gas-liquid mixing system makes it difficult to stabilize the power of the generator set. The gas, liquid, and container walls are considered The dynamic change characteristics of temperature, the air pressure signal, active power signal, and opening signal in the gas-liquid mixing system are introduced into the controller, and the stable control of the power generation process is realized through closed-loop control and control strategy, and the power generation system without power disturbance is realized. The power generation is stable, and the invention provides a control method for the power generation-energy storage system to realize the constant power output of the generator set under pressure fluctuations, and provides important theoretical support and practical basis for improving the flexibility of the power system.

Description of drawings

Fig. 1 is a schematic diagram of the basic principle of the method of the embodiment of the present invention.

Detailed ways

As shown in Figure 1, the fluctuating pressure power generation control method of the power generation-energy storage system in this embodiment includes:

1) Calculate the difference between the measured power value N _meas and the target power value N _ref , and obtain the active power error signal according to the difference between the measured power value N _meas and the target power value N _ref ; calculate the actual air pressure P _mea and set the air pressure value P _ref difference, and obtain the air pressure error signal according to the difference between the actual air pressure P _mea and the set air pressure value Pre _ref , and obtain the multivariable control signal by summing the active power error signal and the air pressure error signal;

2) According to the multivariable control control signal, the working state of the air pressure regulating valve between the high-pressure gas system and the gas-liquid mixing system of the power generation-energy storage system is controlled during the power generation stage.

Referring to Fig. 1, in this embodiment, obtaining the active power error signal according to the difference between the measured power value N _meas and the target power value N _ref refers to inputting the difference between the measured power value N _meas and the target power value N _ref into the active power closed-loop controller To obtain the active power error signal.

Referring to Fig. 1, in this embodiment, obtaining the air pressure error signal according to the difference between the actual air pressure P _mea and the set air pressure value _Pref refers to inputting the difference between the actual air pressure P _mea and the set air pressure value _Pref into the air pressure closed-loop controller to obtain Active power error signal.

In this embodiment, the active power closed-loop controller is a PID controller. In addition, the active power closed-loop controller can also use other types of controllers including fuzzy controllers as required.

In this embodiment, the air pressure closed-loop controller is a PID controller. In addition, the air pressure closed-loop controller can also use other types of controllers including fuzzy controllers as required.

The controller parameter setting of the control method in this embodiment takes into account the dynamic change characteristics of the gas, liquid, and container wall temperatures in the high-pressure gas system and the gas-liquid mixing system in the power generation process; the control method of this embodiment is multivariable control, and the gas-liquid mixing system The air pressure signal in the system and the active power signal of the generator set are introduced into the controller to form a closed-loop air pressure controller and an active power closed-loop controller. In the control method of this embodiment, the mass flow rate of the liquid and the mass flow rate of the gas are input as control input signals, and the air pressure signal in the steam-water mixing container is the output variable.

Furthermore, in order to better realize the parameter design of the active power closed-loop controller and the air pressure closed-loop controller, so as to improve the fluctuating pressure power generation control effect of the power generation-energy storage system, in this embodiment, before step 1), it also includes the active power Steps for parameter design of power closed-loop controller and air pressure closed-loop controller:

S1) Establish the nonlinear differential equations of the temperature, volume and pressure dynamic change characteristics of the gas control body and the liquid controller in the power generation stage:

S2) Transform the nonlinear differential equations of the temperature, volume, and pressure dynamic change characteristics of the gas control body and the liquid controller in the power generation stage into a transfer function, and solve the active power closed-loop controller and the air pressure closed-loop controller according to the relationship between the transfer function and the PID parameters The PID control parameters.

其中Q为体积流量、Q₁₁为单位流量、D₁为直径、H为扬程、a为开度、n₁₁为单位转速。In the power generation stage, the gas-liquid mixing container is connected to drive the hydraulic generator set to generate electricity. The pressure of the gas-liquid mixing container drops from the pressure ps3 to the specified pressure ps1, and the liquid level gradually drops to the initial liquid level; at the same time, the gas storage container and the gas-liquid mixing container part Connected, to control the mass flow rate of high-pressure gas into the gas storage container, so that the pressure of the gas storage container gradually decreases and synchronously drops to the specified initial pressure ps2 when the liquid level of the gas-liquid mixing container drops to the initial liquid level, the initial pressure ps2 is less than the pressure ps1, which is specifically the pressure at the end of the energy storage phase. During the power generation stage, the valve system between the gas-liquid mixing system and the high-pressure gas system is intermittently switched. The switching control law is to maintain the stability of the gas-liquid mixing system in the set pressure range, and the flow rate of the hydraulic power generation device meets

Among them, Q is the volume flow, Q ₁₁ is the unit flow, D ₁ is the diameter, H is the head, a is the opening, and n ₁₁ is the unit speed.

The high-pressure gas system of the power generation-energy storage system stores gas in a gas storage container to build pressure to achieve energy storage. The gas-liquid mixing system stores gas and liquid in a gas-liquid mixing container to build pressure. Therefore, the high-pressure gas system, the gas in the gas-liquid mixing system, and the liquid in the gas-liquid mixing system are the control objects to realize the fluctuating pressure power generation control of the power generation-energy storage system in this embodiment, so they are recorded as gas control body and liquid controller .

In this embodiment, the temperature, volume, and pressure dynamic changes of the gas control body (gas in the high-pressure gas system, gas-liquid mixing system) and liquid controller (liquid in the gas-liquid mixing system) of the power generation stage established in step S1) The nonlinear differential equation of the characteristic is:

y＝g(X)

y=g(X)

为状态变量的微分，X为状态变量，U_u为控制向量，f(X,U_u)为状态变量的微分

与状态变量X以及控制向量U_u两者的函数关系，y为输出，g(X)为输出y与状态变量X之间的函数关系，且有：in,

is the differential of the state variable, X is the state variable, U _u is the control vector, f(X,U _u ) is the differential of the state variable

The functional relationship between the state variable X and the control vector U _u , y is the output, g(X) is the functional relationship between the output y and the state variable X, and there are:

X=[T _B,gas ,T _A,gas ,V _B,gas ,m _{A,gas ,} m _B,gas ,T _l ,Z _l ,T _{gas,T ,} T _l,T ] ^T , U _u =[ u ₁ , u ₂ ] ^T

Among them, T _B,gas , T _A,gas are the temperature of gas control body B in the gas-liquid mixing system and gas control body A in the gas-liquid mixing system respectively, V _B,gas is the temperature of gas control body B in the gas-liquid mixing system Volume, m _{A, gas} , m _{B, gas} are the mass of gas control body A in the gas-liquid mixing system and gas control body B in the gas-liquid mixing system respectively, T _l is the liquid temperature of the gas-liquid mixing container, Z _l is the liquid The liquid level of the control body, T _{gas, T} is the temperature of the gas-liquid mixing container wall, T _{l, T} is the temperature of the container wall in contact with the liquid control body, u ₁ , u ₂ are the control variables, and there are:

分别为状态变量x₁～x₈的微分，x₁～x₉分别为状态变量，k为空气比热容的比值，ρ_w为液体控制器的密度，ρ_l为液体控制体的密度ρ_l＝ρ_w，A_l为液体控制体水平面的面积，c_l为液体控制体的比热容，

为液体控制体出口液体温度，y₁、γ₁～γ₄以及γ₈～γ₁₂均为中间变量，T_amb为环境温度；且有：In the above formula,

are the differentials of the state variables x ₁ ~ x ₈ respectively, x ₁ ~ x ₉ are the state variables respectively, k is the ratio of air specific heat capacity, ρ _w is the density of the liquid controller, ρ _l is the density of the liquid control body ρ _l = ρ _w , A _l is the area of the horizontal plane of the liquid control body, c _l is the specific heat capacity of the liquid control body,

is the liquid temperature at the outlet of the liquid control body, y ₁ , γ ₁ ~ γ ₄ and γ ₈ ~ γ ₁₂ are all intermediate variables, T _amb is the ambient temperature; and there are:

m_gas,Tc_T＝γ₈，

ρ_lA_l＝γ₅，h_gas,TA_gas,T＝γ₉，h_oA_o,gas＝γ₁₀，h_{l, T}A_l,T＝γ₁₁，h_gas,lA_l＝γ₁₂，

m _gas,T c _T =γ ₈ ,

ρ _l A _l = γ ₅ , h _{gas, T} A _{gas, T} = γ ₉ , h _o A _{o, gas} = γ ₁₀ , h _{l, T} A _{l, T} = γ ₁₁ , h _{gas, l} A _l = γ ₁₂ ,

为高压气系统内空气控制体A、气液混合系统内空气控制体B之间的交换速率，

为汽液混合容器内液体控制器的质量流出流率，m_gas,T为与空气接触的容器器壁控制体质量，c_T为气液混合容器器壁的比热容，

表示气液混合系统内空气控制体B的空气定容比热容，U为与环境接触器壁的换热系数，A_G为气液混合系统内空气控制体B与气体接触的器壁面积，

表示气液混合系统内空气控制体A的空气定容比热容，R_g为空气气体常数，ρ_w为汽液混合容器内液体控制体的密度，h_gas,T为气体控制体与容壁之间的换热系数，A_gas,T为气体控制体与汽液混合容器器壁接触的面积，h_o为气液混合容器器壁与外部环境之间换热系数，A_o,gas为与气液混合容器内部空气接触的器壁暴露在外部环境的面积，h_l,T为液体与汽液混合容器器壁之间的换热系数，A_l,T为液体控制体与汽液混合容器器壁接触的面积，p_B,gas为气液混合系统内空气控制体B的压力。In the above formula,

is the exchange rate between the air control body A in the high-pressure gas system and the air control body B in the gas-liquid mixing system,

is the mass outflow rate of the liquid controller in the gas-liquid mixing vessel, m _{gas, T} is the mass of the control body on the wall of the vessel in contact with the air, c _T is the specific heat capacity of the wall of the gas-liquid mixing vessel,

Indicates the specific heat capacity of the air at constant volume of the air control body B in the gas-liquid mixing system, U is the heat transfer coefficient with the environment contactor wall, A _G is the wall area of the air control body B in the gas-liquid mixing system in contact with the gas,

Indicates the constant-volume specific heat capacity of the air control body A in the gas-liquid mixing system, R _g is the air gas constant, ρ _w is the density of the liquid control body in the gas-liquid mixing container, h _{gas, T} is the distance between the gas control body and the volume wall The heat transfer coefficient, A _gas,T is the contact area between the gas control body and the gas-liquid mixing container wall, h _o is the heat transfer coefficient between the gas-liquid mixing container wall and the external environment, A _o,gas is the gas-liquid mixing container wall The area of the wall of the mixing vessel that is in contact with the air and exposed to the external environment, h _l,T is the heat transfer coefficient between the liquid and the wall of the vapor-liquid mixing vessel, A _l,T is the liquid control body and the wall of the vapor-liquid mixing vessel The contact area, p _{B, gas} is the pressure of the air control body B in the gas-liquid mixing system.

In this embodiment, step S2) includes:

S2.1) According to the current state variable value, the nonlinear differential equation of the temperature, volume and pressure dynamic change characteristics of the gas control body and the liquid controller in the power generation stage is linearized to obtain the linearization equation:

y＝C(X_e)X_e

y=C(X _e )X _e

In the above formula, A is the system matrix, B is the input matrix, and C is the output matrix, and there are:

Among them, f is the functional relationship between the differential equation and the state variable X and the control vector U;

S2.2) Transform the linearization equation into the state space equation of the transfer function G(s) of the state variable point X _e at the current moment t shown in the following formula:

G(s)＝C(X _e )(sI-A) ^-1 B(X _e )

In the above formula, I is the identity matrix, and A is the system matrix;

的闭环特征方程根；S2.3) According to the transfer function _Gc (s) of the PID control law shown in the following formula and the transfer function G(s) of the state variable point _Xe at the current moment t, the control system at the current moment t is obtained

The root of the closed-loop characteristic equation;

In the above formula, K _p , K _i , K _d are PID control parameters, and T _1v is the actual differential link time constant;

稳定的闭环特征方程根进行极点配置，建立闭环系统极点与PID参数的关系，从而求得PID控制参数K_p,K_i,K_d。S2.4) to ensure that the control system

The stable closed-loop characteristic equation roots are configured with poles, and the relationship between the closed-loop system poles and PID parameters is established, so as to obtain the PID control parameters K _p , K _i , K _d .

In addition, this embodiment also provides a fluctuating pressure power generation control device for applying the aforementioned fluctuating pressure power generation control method of a power generation-energy storage system, including:

The control unit is used to calculate the difference between the measured power value N _meas and the target power value N _ref , and obtain an active power error signal according to the difference between the measured power value N _meas and the target power value N _ref ; calculate the actual air pressure P _mea , set the air pressure value P _ref , and obtain the air pressure error signal according to the difference between the actual air pressure P _mea and the set air pressure value P _ref , and obtain the multivariable control signal by summing the active power error signal and the air pressure error signal;

The valve control module is used to control the working state of the air pressure regulating valve between the high-pressure gas system and the gas-liquid mixing system of the power generation-energy storage system in the power generation stage according to the multivariable control control signal;

The output end of the control unit is connected with the valve control module, and the valve control module is used for connecting with the control end of the air pressure regulating valve between the high-pressure gas system and the gas-liquid mixing system of the power generation-energy storage system.

In this embodiment, the control unit includes: an active power error calculation unit for calculating the difference between the measured power value N _meas and the target power value N _ref ; an active power closed-loop controller for calculating the difference between the measured power value N _meas and the target The difference between the power value N _ref is used to obtain the active power error signal; the air pressure error calculation unit is used to calculate the difference between the actual air pressure P _mea and the set air pressure value P _ref ; the air pressure closed-loop controller is used to set the air pressure according to the actual air pressure P _mea The difference of the value P _ref obtains the air pressure error signal; the summation module is used to sum the active power error signal and the air pressure error signal to obtain a multivariable control control signal; the output terminal of the active power error calculation unit is connected with the active power closed-loop controller The input end of the air pressure closed-loop controller is connected to each other, the output end of the air pressure closed-loop controller is connected to the input end of the air pressure closed-loop controller, the output ends of the active power closed-loop controller and the air pressure closed-loop controller are connected to the input end of the summation module, The output end of the summation module is connected with the valve control module; the active power closed-loop controller and air pressure closed-loop controller are PID controllers.

Those skilled in the art should understand that the embodiments of the present application may be provided as methods, systems, or computer program products. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-readable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) having computer-usable program code embodied therein. The present application is described with reference to flowcharts and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the present application. It should be understood that each procedure and/or block in the flowchart and/or block diagram, and a combination of procedures and/or blocks in the flowchart and/or block diagram can be realized by computer program instructions. These computer program instructions may be provided to a general purpose computer, special purpose computer, embedded processor, or processor of other programmable data processing equipment to produce a machine such that the instructions executed by the processor of the computer or other programmable data processing equipment produce a An apparatus for realizing the functions specified in one or more procedures of the flowchart and/or one or more blocks of the block diagram. These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing apparatus to operate in a specific manner, such that the instructions stored in the computer-readable memory produce an article of manufacture comprising instruction means, the instructions The device realizes the function specified in one or more procedures of the flowchart and/or one or more blocks of the block diagram. These computer program instructions can also be loaded onto a computer or other programmable data processing device, causing a series of operational steps to be performed on the computer or other programmable device to produce a computer-implemented process, thereby The instructions provide steps for implementing the functions specified in the flow chart or blocks of the flowchart and/or the block or blocks of the block diagrams.

The above descriptions are only preferred implementations of the present invention, and the protection scope of the present invention is not limited to the above-mentioned embodiments, and all technical solutions under the idea of the present invention belong to the protection scope of the present invention. It should be pointed out that for those skilled in the art, some improvements and modifications without departing from the principles of the present invention should also be regarded as the protection scope of the present invention.

Claims (9)

1. A fluctuating pressure power generation control method of a power generation-energy storage system, characterized by comprising:

1) Calculating the measured power value N _meas Target power value N _ref The difference is determined according to the measured power value N _meas Target power value N _ref Obtaining an active power error signal by the difference; calculating the actual pressure P _mea Setting a pressure value P _ref Difference between them, and according to actual air pressure P _mea Setting a pressure value P _ref Obtaining an air pressure error signal according to the difference, and summing the active power error signal and the air pressure error signal to obtain a multivariable control signal;

2) Controlling the working state of a gas pressure regulating valve between a high-pressure gas system and a gas-liquid mixing system of the power generation-energy storage system at a power generation stage according to a multivariable control signal;

before the step 1), the method also comprises the step of carrying out parameter design on the active power closed-loop controller and the pneumatic closed-loop controller: s1) establishing a nonlinear differential equation of the dynamic change characteristics of the temperature, the volume and the pressure of a gas control body and a liquid controller in the power generation stage: and S2) converting nonlinear differential equations of dynamic change characteristics of temperature, volume and pressure of the gas control body and the liquid controller in the power generation stage into transfer functions, and solving PID control parameters of the active power closed-loop controller and the pneumatic closed-loop controller according to the relation between the transfer functions and PID parameters.

2. The fluctuating pressure power generation control method of a power generation-energy storage system according to claim 1, wherein the power generation control method is based on a measured power value N _meas Target power value N _ref Obtaining the active power error signal by the difference is to obtain the measured power value N _meas Target power value N _ref The difference is input into an active power closed-loop controller to obtain an active power error signal.

3. The fluctuating pressure power generation control method of power generation-energy storage system according to claim 2, characterized in that said actual air pressure P is used as a function of _mea Setting a pressure value P _ref Obtaining the air pressure error signal from the difference is to obtain the actual air pressure P _mea Setting a pressure value P _ref The difference is input into a pneumatic closed-loop controller to obtain an active power error signal.

4. The fluctuating pressure power generation control method of a power generation-energy storage system according to claim 3, wherein the active power closed-loop controller is a PID controller.

5. The fluctuating pressure power generation control method of a power generation-energy storage system according to claim 4, wherein the pneumatic closed-loop controller is a PID controller.

6. The fluctuating pressure power generation controlling method of a power generation-energy storage system according to claim 1, wherein the nonlinear differential equations of the temperature, volume, pressure dynamics of the gas control body and the liquid control body in the power generation stage established in step S1) are:

y＝g(X)

wherein,

is the differential of the state variable, X is the state variable, U _u To control the vector, f (X, U) _u ) As a differentiation of the state variable

With the state variable X and the control vector U _u The functional relationship between the two, y being the output, g (X) being the functional relationship between the output y and the state variable X, and having:

X＝[T _B,gas ,T _A,gas ,V _B,gas ,m _A,gas ,m _B,gas ,T _l ,Z _l ,T _gas,T ,T _l,T ] ^T ，U _u ＝[u ₁ ,u ₂ ] ^T

wherein, T _B,gas ,T _A,gas Respectively the temperature and V of a gas control body B in the gas-liquid mixing system and a gas control body A in the gas-liquid mixing system _B,gas The volume m of the gas control body B in the gas-liquid mixing system _A,gas ,m _B,gas Respectively the mass T of the gas control body A in the gas-liquid mixing system and the mass T of the gas control body B in the gas-liquid mixing system _l Is the liquid temperature of the gas-liquid mixing vessel, Z _l For controlling the level of the body, T _gas,T Is the temperature, T, of the wall of the vapor-liquid mixing vessel _l,T Temperature of vessel wall in contact with liquid control body u ₁ ,u ₂ Are control variables and have:

in the above formula, the first and second carbon atoms are,

are respectively a state variable x ₁ ～x ₈ Differential of (a), x ₁ ～x ₉ Respectively as state variables, k is the ratio of air specific heat capacity, rho _w Density of fluid control, p _l Controlling the density of the body for the liquid rho _l ＝ρ _w ，A _l Is the area of the horizontal plane of the liquid control body, c _l Is the specific heat capacity of the liquid control body,

controlling the temperature of the liquid at the outlet for the liquid, y ₁ 、γ ₁ ～γ ₄ And gamma ₈ ～γ ₁₂ Are all intermediate variables, T _amb Is ambient temperature; and has the following components:

m _gas,T c _T ＝γ ₈ ，

ρ _l A _l ＝γ ₅ ，

h _gas,T A _gas,T ＝γ ₉ ，h _o A _o,gas ＝γ ₁₀ ，h _l,T A _l,T ＝γ ₁₁ ，h _gas,l A _l ＝γ ₁₂ ，

in the above formula, the first and second carbon atoms are,

is the exchange rate between an air control body A in a high-pressure air system and an air control body B in an air-liquid mixing system,

mass outflow rate, m, of a liquid controller in a vapor-liquid mixing vessel _gas,T Controlling the mass of the container wall in contact with air, c _T Is the specific heat capacity of the wall of the gas-liquid mixing container,

represents the air constant volume specific heat capacity of an air control body B in the gas-liquid mixing system, U is the heat exchange coefficient of the wall of the air control body B contacting with the environment, A _G The wall area of the air control body B in the gas-liquid mixing system contacted with the gas,

represents the air constant volume specific heat capacity R of the air control body A in the gas-liquid mixing system _g Is the air gas constant, ρ _w Controlling the density, h, of the liquid in the vapor-liquid mixing vessel _gas,T Is the heat exchange coefficient between the gas control body and the containment wall, A _gas,T For controlling the contact area of the gas and the wall of the gas-liquid mixing container, h _o Is the heat exchange coefficient between the wall of the gas-liquid mixing container and the external environment, A _o,gas Is with qi and bloodArea of the air-contacting wall inside the liquid mixing container exposed to the external environment, h _l,T Is the heat transfer coefficient between the walls of the liquid and vapor-liquid mixing vessels, A _l,T For controlling the area of contact of the liquid with the wall of the vapour-liquid mixing vessel, p _B,gas The pressure of the air control body B in the gas-liquid mixing system.

7. The fluctuating pressure electric power generation control method of the electric power generation-storage system according to claim 6, characterized in that step S2) includes:

s2.1) according to the value of the current state variable, carrying out linearization on nonlinear differential equations of dynamic change characteristics of temperature, volume and pressure of the gas control body and the liquid controller in the power generation stage to obtain a linearized equation:

y＝C(X _e )X _e

in the above formula, A is the system matrix, B is the input matrix, C is the output matrix, and has:

wherein f is a functional relation between a differential equation and the state variable X and the control vector U;

s2.2) converting the linearized equation into a state variable point X at the current time t shown in the following formula _e The state space equation of the transfer function G(s) of (b):

G(s)＝C(X _e )(sI-A) ^-1 B(X _e )

in the above formula, I is an identity matrix, and a is a system matrix;

s2.3) transfer function G according to PID control law shown in the following formula _c (s) and the state variable point X at the current time t _e Control system for obtaining current time t by transfer function G(s) of (2)

The closed-loop characteristic equation root of (1);

in the above formula, K _p ,K _i ,K _d For PID control parameters, T _1v Is the actual differential link time constant;

s2.4) to ensure the control system

The stable closed-loop characteristic equation root is used for pole allocation, and the relation between the pole of the closed-loop system and the PID parameter is established, so that the PID control parameter K is obtained _p ,K _i ,K _d 。

8. A fluctuating-pressure electric power generation control apparatus for applying the fluctuating-pressure electric power generation control method of the electric power generation-storage system according to any one of claims 1 to 7, characterized by comprising:

a control unit for calculating a measured power value N _meas Target power value N _ref The difference is determined according to the measured power value N _meas Target power value N _ref Obtaining an active power error signal according to the difference; calculating the actual pressure P _mea Setting a pressure value P _ref The difference is based on the actual pressure P _mea Setting a pressure value P _ref Obtaining an air pressure error signal according to the difference, and summing the active power error signal and the air pressure error signal to obtain a multivariable control signal;

the valve control module is used for controlling the working state of a gas pressure regulating valve between a high-pressure gas system and a gas-liquid mixing system of the power generation-energy storage system in a power generation stage according to a multivariable control signal;

the output end of the control unit is connected with a valve control module, and the valve control module is used for being connected with the control end of a pneumatic pressure regulating valve between a high-pressure air system and a gas-liquid mixing system of the power generation-energy storage system.

9. The fluctuating pressure electric power generation control device according to claim 8, characterized in that the control unit includes:

an active power error calculation unit for calculating the measured power value N _meas Target power value N _ref The difference between the two; an active power closed-loop controller for controlling the active power according to the measured power value N _meas Target power value N _ref Obtaining an active power error signal according to the difference; an air pressure error calculating unit for calculating the actual air pressure P _mea Setting a pressure value P _ref The difference between the two; a pneumatic closed-loop controller for controlling the pneumatic pressure according to the actual pneumatic pressure P _mea Setting a pressure value P _ref Obtaining an air pressure error signal according to the difference; the summation module is used for summing the active power error signal and the air pressure error signal to obtain a multivariable control signal; the output end of the active power error calculation unit is connected with the input end of an active power closed-loop controller, the output end of the pneumatic closed-loop controller is connected with the input end of a summation module, the output ends of the active power closed-loop controller and the pneumatic closed-loop controller are connected with the input end of the summation module, and the output end of the summation module is connected with a valve control module; the active power closed-loop controller and the air pressure closed-loop controller are PID controllers.

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