CN109241549B - A Modeling Method of Energy Distributor Based on Bus Structure - Google Patents

Abstract

The invention discloses a modeling method of an energy distributor based on a bus structure. The planning of traditional energy systems only faces a single energy system, which artificially separates the optimal allocation of resources in each energy system and reduces the overall energy utilization efficiency. The modeling method of the present invention includes the steps of: 1) establishing multiple bus-type interface models according to user requirements; 2) combining the multiple bus-type interface models according to actual application scenarios to obtain an energy distributor. The invention uniformly dispatches the four energy sources of electricity, heat, cold and gas, rationally configures the use of energy sources, and gives full play to the complementary characteristics and synergistic effects of different energy forms; the invention makes the internal structure of the energy distributor clear and concise, and is convenient for users Carry out modular modeling, and carry out bus-based modeling for the interior of the energy distributor according to the type of energy conversion device.

Description

A Modeling Method of Energy Distributor Based on Bus Structure

technical field

The invention relates to the field of optimal operation of multi-energy systems including electricity, heat, cooling and gas, in particular to a modeling method of an energy distributor based on a bus structure.

Background technique

According to China's energy development strategy, the proportion of renewable energy power generation will reach more than 85% by 2050, of which the combined proportion of wind power and photovoltaics will reach 63%. However, the use of renewable energy represented by wind and solar is facing severe wind and solar abandonment situations. Taking 2015 as an example, China’s abandoned wind power reached 3.39×1010KWh, the wind abandonment rate was 15%, and the wind abandonment loss was about 17 billion yuan. . The lack of flexibility of the energy system is the main reason leading to curtailment of wind and light. The random fluctuation of wind power and photovoltaic output reduces the supply of energy system flexibility and increases the demand for system flexibility. On the other hand, thermal power units improve the system Comprehensive efficiency, but reduces the adjustment capacity of the overall energy system, which has become a major factor leading to the lack of flexibility of the energy system in the Three North region. The regional-level energy system represented by parks has the characteristics of high energy consumption density, high load utilization hours, increased proportion of renewable energy, and diversified forms of energy production and consumption. An effective way to comprehensively utilize efficiency and achieve energy-saving and emission-reduction goals. China currently has nearly 2,000 national and provincial development zones, which are the most urgently needed and the best entry point for promoting the development of regional comprehensive systems, with broad development prospects and opportunities.

The planning of traditional energy systems only faces a single energy system, such as electricity, gas, heat (cold), which artificially separates the optimal allocation of resources in each energy system and reduces the overall energy utilization efficiency. In response to this phenomenon, in the context of solving large-scale renewable energy consumption, researchers proposed the concept of collaborative planning of heterogeneous energy flow systems, that is, organic coupling of various types of energy systems such as electricity, gas, heat (cold), etc., to provide A physical platform for the comprehensive utilization of multiple energies, giving full play to the complementary characteristics and synergistic effects of different energy forms, realizing optimal allocation of energy system resources in a wider range, improving system flexibility, and improving renewable energy consumption capacity and overall system energy efficiency .

Contents of the invention

Aiming at the problems existing in the above-mentioned prior art, the present invention provides a modeling method of an energy distributor based on a bus structure. This method uniformly dispatches the four energy sources of electricity, heat, cooling and gas, and rationally configures the use of energy sources. Give full play to the complementary characteristics and synergistic effects of different energy forms.

For this reason, the present invention adopts following technical scheme: a kind of modeling method based on the energy allocator of bus type structure, it comprises:

1) Establish multiple bus-type interface models according to user needs, and connect energy conversion devices with corresponding bus types according to energy conversion types;

2) According to the actual application scenario, multiple bus interface models are combined to obtain an energy distributor.

Further, in the step 1), the bus interface model includes a power-power bus interface model, and its calculation formula is as follows:

PL _out = PL _in ·η _T +P _PV +P _WP +P _BT ,

In the formula, PL _in / PL _out represent the electric energy input/output by the power bus, η _T represents the efficiency of the transformer, P _PV represents the photovoltaic power generation, P _WP represents the wind power generation, P _BT represents the charge/discharge capacity of the battery, discharge It is positive when it is charged, and it is negative when it is charged;

The power-power bus interface model integrates transformers, photovoltaic power generation, wind turbine power generation and storage batteries. The transformer is mainly used to connect to the external large power grid. Whether the transformer is running or not will determine the working status of the energy distributor. Interact with the external grid to stabilize renewable energy; when the energy distributor is in an island state, the battery is used to stabilize the fluctuations generated by solar and wind power generation, and also play the role of peak shaving and valley filling.

Further, in the step 1), the bus interface model includes the power-thermal bus interface model, and its calculation formula is as follows:

HL _out = (λ _P-EB + λ _p-EP · COP) · PL _in + H _HS ,

In the formula, HL _out represents the heat energy output from the thermal bus, PL _in represents the electric energy input from the power bus, λ _P-EB represents the distribution coefficient of electric energy obtained by the electric boiler from PL _in , and λ _P-EP represents the heat pump obtained from PL _in The distribution coefficient of electric energy, COP indicates the heating energy efficiency ratio of the heat pump, H _HS indicates the charging/discharging heat capacity of the heat storage tank, a positive number indicates heat release, and a negative number indicates heat storage;

The power-heat bus interface model integrates electric boilers, heat pumps and heat storage tanks. When the central heating system cannot provide enough heat sources and there is a surplus of electricity, start the electric boiler or heat pump to convert part of the electric energy into heat energy to make up for short-term heat supply shortages ;Using heat storage tanks to realize peak shift regulation of electricity and heat is the key equipment for shifting heat loads.

Further, in the step 1), the bus interface model includes a power-cooling bus interface model, and its calculation formula is as follows:

CL _out = PL _in ·η _EC +C _CS ,

In the formula, CL _out represents the cooling capacity of the cold power bus, PL _in represents the electric energy input by the power bus, η _EC represents the efficiency of the electric refrigeration equipment, C _CS represents the charging/discharging capacity of the cold storage tank, and a positive number represents cooling , a negative number means cold storage;

The power-cooling bus interface model integrates the electric refrigerator and cold storage tank.

Further, in the step 1), the bus interface model includes a power-cooling bus interface model, and its calculation formula is as follows:

GL _out = PL _in ·η _P2G +G _GS ,

In the formula, GL _out represents the gas discharge volume of the natural gas bus, PL _in represents the electric energy input by the power bus, η _P2G represents the conversion efficiency of the P2G equipment, G _GS represents the gas filling/deflation capacity of the gas storage tank, positive numbers represent gas deflation, and negative numbers means to store gas;

The power-gas bus interface model mainly integrates power-to-gas equipment and gas storage tanks.

Further, in the step 1), the bus interface model includes a natural gas-thermal bus interface model, and its calculation formula is as follows:

HL _out = (λ _G-CHP η _CHP-H + λ _G-GB η _GB ) GL _in + H _HS ,

In the formula, HL _out represents the heat energy output from the thermal bus, GL _in represents the natural gas volume input from the natural gas bus, λ _G-CHP represents the distribution coefficient of the natural gas volume obtained by the cogeneration unit from GL _in , and λ _G-GB represents the gas The boiler gets the distribution coefficient of natural gas from GL _in , η _CHP-H represents the gas-to-heat conversion efficiency of the cogeneration unit, η _GB represents the gas efficiency of the gas-fired boiler, H _HS represents the charging/discharging heat capacity of the heat storage tank, a positive number Indicates heat release, and negative numbers indicate heat storage;

The natural gas-thermal bus interface model integrates gas-fired cogeneration units, gas boilers, gas storage tanks and heat storage tanks.

Further, in the step 1), the bus-type interface model includes a heat-cooling bus interface model, and its calculation formula is as follows:

CL _out = PL _in η _AC + C _CS ,

In the formula, η _AC represents the conversion efficiency of the absorption refrigerating machine, PL _in represents the electric energy input by the power bus, C _CS represents the charging/discharging cooling capacity of the cold storage tank, a positive number indicates cooling, and a negative number indicates cold storage;

The heat-cool bus interface model integrates an absorption chiller and a cold storage tank.

Further, the step 2) specifically includes: according to the specific requirements of the actual user for the type and quantity of energy, rationally select and combine multiple bus interface models, and finally obtain a reasonable type and quantity of the energy conversion device in the energy distributor and topology.

Compared with the prior art, the present invention has the beneficial effects that: the structure of the energy distributor obtained by using the present invention contains almost all energy conversion devices commonly used in the energy distributor, and the internal structure of the energy distributor is built into a bus The module makes the internal topology of the energy divider more clear and easy to read, and facilitates the modular design of the energy divider designer.

Description of drawings

Fig. 1 is the schematic diagram of the power-power bus interface model of the present invention;

Fig. 2 is a schematic diagram of the power-thermal bus interface model of the present invention;

Fig. 3 is the schematic diagram of the power-cooling force bus interface model of the present invention;

Fig. 4 is the schematic diagram of electric power-natural gas bus interface model of the present invention;

Fig. 5 is the schematic diagram of the natural gas-thermal bus interface model of the present invention;

Fig. 6 is a schematic diagram of the present invention's thermal-cooling bus interface model;

Fig. 7 is the topological structure diagram of the civilian energy distributor obtained by adopting the method of the present invention;

Fig. 8 is a topological structure diagram of an industrial energy distributor obtained by adopting the method of the present invention.

Detailed ways

This embodiment provides a modeling method for an energy distributor based on a bus structure, the method comprising:

(1) Establish multiple bus interface models according to user needs

(1-1) Establish a power-power bus interface model

The power-power bus interface model is shown in Figure 1. In the figure, T: transformer, PV: solar energy, WP: wind power, BT: battery, and the calculation formula is:

PL _out ＝PL _in ·η _T +P _PV +P _WP +P _BT (1)

In formula (1), PL _in / PL _out represent the electric energy input/output by the power bus, η _T represents the efficiency of the transformer, P _PV represents the photovoltaic power generation, P _WP represents the wind power generation, P _BT represents the charging/discharging of the battery The amount is positive when discharging and negative when charging.

The power-power bus interface model integrates transformers, photovoltaics, wind turbines and batteries. The transformer is mainly used to connect to the external large power grid. Whether the transformer is running or not will determine the working state of the energy distributor (network mode/island mode). When the energy distributor is in the network mode, the renewable energy can be stabilized by interacting with the external grid through the transformer. When the energy distributor is operating in an isolated state, the battery is used to stabilize the fluctuations generated by solar and wind power generation, and at the same time play a certain role in peak shaving and valley filling.

(1-2) Establish the power-thermal bus interface model

The power-heat bus interface model is shown in Figure 2. In the figure, EB: electric boiler, EP: heat pump, HS: heat storage tank, and the calculation formula is:

HL _out ＝(λ _P-EB +λ _p-EP ·COP)·PL _in +H _HS (2)

In formula (2), HL _out represents the thermal energy output from the thermal bus, λ _P-EB represents the distribution coefficient of the electric boiler from PL _in , λ _P-EP represents the distribution coefficient of the heat pump from PL _in , and COP represents The heating energy efficiency ratio of the heat pump, H _HS represents the charging/discharging heat of the heat storage tank, a positive number indicates heat release, and a negative number indicates heat storage.

The Power-Heat bus interface model integrates electric boilers, heat pumps and thermal storage tanks. When the central heating system cannot provide enough heat source and there is a surplus of electricity, the electric boiler or heat pump can be started to convert part of the electric energy into heat energy to make up for the short-term heat supply shortage. The use of heat storage tanks can realize peak shift regulation of electricity and heat, which is the key equipment for shifting heat loads.

(1-3) Establish the power-cooling force bus interface model

The power-cooling power bus interface model is shown in Figure 3. In the figure, EC: electric refrigeration equipment, CS: cold storage tank, and the calculation formula is:

CL _out = PL _in η _EC + C _CS (3)

In formula (3), CL _out represents the cooling capacity of the cooling bus, η _EC represents the efficiency of the electric refrigeration equipment, C _CS represents the charging/discharging capacity of the cold storage tank, a positive number represents cooling, and a negative value represents cold storage.

The power-cooling bus interface model integrates the electric refrigerator and cold storage tank. This interface is mainly used in summer. When the ambient temperature is high, a large number of electric refrigeration equipment is turned on, resulting in a large increase in power consumption. By storing cold in the cold storage tank in advance, it can cut peaks and fill valleys.

(1-4) Establish the interface model of electric power-natural gas bus

The power-natural gas bus interface model is shown in Figure 4. In the figure, P2G: power-to-gas, GS: gas storage tank, and its calculation formula is:

GL _out = PL _in η _P2G + G _GS (4)

In formula (4), GL _out represents the outgassing amount of the natural gas bus, η _P2G represents the conversion efficiency of the P2G equipment, G _GS represents the gas filling/deflation amount of the gas storage tank, positive numbers represent gas deflation, and negative numbers represent gas storage.

The power-gas bus interface model mainly integrates power-to-gas equipment and gas storage tanks. With the increasing maturity of power-to-gas technology, large-scale storage of electric energy becomes possible. Natural gas is an energy source that is convenient for storage and transportation. Gas storage methods are divided into gas storage, liquid storage and solid storage. Gas storage includes gas storage cabinet storage, underground gas storage storage, etc. Liquid storage mainly adopts storage methods at low temperature and atmospheric pressure, such as cave storage in permafrost, storage in above-ground metal storage tanks, etc. Solid-state storage is mainly to convert natural gas into solid crystalline hydrate under certain pressure and temperature.

(1-5) Establish a natural gas-thermal bus interface model

The natural gas-thermal bus interface model is shown in Figure 5. In the figure, GS: gas storage tank, CHP: combined heat and power unit, HS: heat storage tank, GB: gas boiler, and the calculation formula is:

HL _out = (λ _G-CHP η _CHP-H + λ _G-GB η _GB ) GL _in + H _HS (5)

In formula (5), GL _in represents the amount of natural gas input from the natural gas bus, λ _G-CHP represents the distribution coefficient of natural gas obtained from GL _in by the cogeneration unit, and λ _G-GB represents the natural gas obtained from GL _in by the gas boiler η _CHP-H represents the gas-to-heat conversion efficiency of the cogeneration unit, and η _GB represents the gas efficiency of the gas-fired boiler.

The natural gas-thermal bus interface model integrates gas-fired cogeneration units, gas-fired boilers, gas storage tanks and heat storage tanks. The combined heat and power unit is the core equipment of the energy distributor, which converts natural gas into electricity and heat. When the heating demand is large, the gas boiler can also be used to directly burn natural gas for heating, and the gas storage tank is used to ensure the stable and reliable supply of natural gas.

(1-6) Establish a heat-cooling bus interface model

The heat-cooling bus interface model is shown in Figure 6. In the figure, AC: absorption chiller, CS: cold storage tank, the calculation formula is:

CL _out = PL _in η _AC + C _CS (6)

In formula (6), η _AC represents the conversion efficiency of the absorption refrigerator.

The heat-cool bus interface model integrates an absorption chiller and a cold storage tank. Absorption chillers are usually used with combined heat and power units to achieve cascade utilization of energy by absorbing gas waste heat for refrigeration. Absorption refrigerators have low demand for electric energy, and can bear part of the air-conditioning load in summer, so as to reduce the demand for electric power of electric refrigeration equipment.

(2) According to the actual application scenario, the bus model is combined to obtain the energy distributor. According to the specific requirements of the actual user for the type and quantity of energy, multiple bus interface models are reasonably selected and combined to finally obtain a reasonable type, quantity and topology of the energy conversion devices in the energy distributor.

The civil energy distributor is as shown in accompanying drawing 7. The internal structure of the civil energy distributor is relatively simple compared with the other two hubs. Mainly consider the user's demand for electricity, cold and heat. Renewable energy power generation devices can be installed on the roof. Micro gas turbines occupy a small area and cause little pollution. They are the core equipment for cogeneration of heat and power. In terms of heating, considering the coordination of electric load and gas load, the electric boiler and gas boiler are integrated into the energy distributor. In terms of refrigeration, air conditioners are mainly used. When conditions permit, absorption refrigeration equipment can be added. Considering the land occupation and the interruptibility of some loads, the civil energy distributor does not involve energy storage, and its matrix form is shown in formula (7).

In formula (7), λ _PT is the distribution coefficient of the transformer, λ _P-EB is the distribution coefficient of the electric boiler, η _EB is the efficiency of the electric boiler, and λ _H-AC is the heat distribution obtained by the absorption refrigerator from HL _out coefficient, η _AC represents the efficiency of the absorption refrigerator, λ _P-EC is the distribution coefficient of the electric refrigeration equipment, and η _CHP-P is the gas-to-electricity conversion efficiency of the combined heat and power unit.

The industrial energy distributor is shown in Figure 8. Due to the large area of the industrial park, the industrial energy distributor has added P2G equipment on the basis of the civil energy distributor. Through P2G technology, the power generation of renewable energy can be fully utilized to realize large-scale storage of renewable energy. Since the floor area of the equipment in the industrial park is hardly considered, and in order to ensure the long-term reliable operation of industrial production, the matrix form of the industrial energy distributor is shown in formula (8).

In formula (8), λ _P-P2G represents the distribution coefficient of power-to-gas equipment obtained from the power bus.

What is disclosed above is only a preferred embodiment of the present invention, which cannot limit the scope of rights of the present invention. Therefore, equivalent changes made according to the claims of the present invention still fall within the scope of the present invention.

Claims (8)

1. A modeling method for a bus-based energy distributor, comprising:

1) Establishing a plurality of bus type interface models according to user requirements, and connecting energy conversion equipment with corresponding bus types according to energy conversion types;

2) Combining a plurality of bus type interface models according to an actual application scene to obtain an energy distributor;

in step 1), the bus interface model includes a power-power bus interface model, and the calculation formula is as follows:

PL _out ＝PL _in ·η _T +P _PV +P _WP +P _BT ，

in the formula, PL _in /PL _out Representing electric energy input/output by an electric bus, eta, respectively _T Representing the efficiency of the transformer, P _PV Representing photovoltaic power generation, P _WP Indicating wind power generation capacity, P _BT Representing the charge/discharge capacity of the storage battery, wherein the charge/discharge capacity is positive during discharge and negative during charge;

in step 1), the bus interface model includes an electric power-thermal power bus interface model, and the calculation formula is as follows:

HL _out ＝(λ _P-EB +λ _p-EP ·COP)·PL _in +H _HS ，

in the formula, HL _out Representing the thermal energy, PL, output from the thermal bus _in Representing electric energy input from an electric bus, λ _P-EB Indicating electric boilers from PL _in Obtaining the distribution coefficient of electric energy, lambda _P-EP Indicating heat pump slave PL _in Obtaining the distribution coefficient of electric energy, COP represents the heating energy efficiency ratio of the heat pump, H _HS Showing the heat charging/discharging amount of the heat storage tank, positive numbers showing heat discharging, and negative numbers showingStoring heat;

in step 1), the bus interface model includes an electric power-cold power bus interface model, and the calculation formula is as follows:

CL _out ＝PL _in ·η _EC +C _CS ，

in the formula, CL _out Indicating the amount of cold drawn from the cold bus, PL _in Representing electric energy input by an electric power bus, eta _EC Indicating the efficiency of the electric refrigerating apparatus, C _CS The cold charging/discharging quantity of the cold storage tank is represented, positive numbers represent cold discharging, and negative numbers represent cold storage;

in the step 1), the bus type interface model comprises an electric power-natural gas bus interface model, and the calculation formula is as follows:

GL _out ＝PL _in ·η _P2G +G _GS ，

in the formula, GL _out Indicating the discharge capacity, PL, of a natural gas bus _in Representing electric energy input by an electric power bus, eta _P2G Representing the conversion efficiency of a P2G plant, G _GS The gas charging/discharging quantity of the gas storage tank is represented, positive numbers represent gas discharging, and negative numbers represent gas storage;

in the step 1), the bus type interface model comprises a natural gas-thermal bus interface model, and the calculation formula is as follows:

HL _out ＝(λ _G-CHP ·η _CHP-H +λ _G-GB ·η _GB )·GL _in +H _HS ，

in the formula, HL _out Representing the thermal energy output from the thermal bus, GL _in Representing the amount of natural gas, lambda, input from the natural gas bus _G-CHP Indicating cogeneration units from GL _in Obtaining the distribution coefficient, lambda, of the natural gas quantity _G-GB Indicating gas-fired boiler from GL _in Obtaining the distribution coefficient eta of the natural gas quantity _CHP-H Indicates the gas-heat conversion efficiency, eta, of the cogeneration unit _GB Indicating the gas efficiency of the gas boiler, H _HS Represents the heat charging/discharging amount of the heat storage tank, positive numbers represent heat discharging, and negative numbers represent heat storage;

in step 1), the bus interface model includes a thermal-cold bus interface model, and the calculation formula is as follows:

CL _out ＝PL _in ·η _AC +C _CS ，

in the formula eta _AC Indicating the conversion efficiency, PL, of an absorption chiller _in Representing electrical energy input from the power bus, C _CS The cold charging/discharging quantity of the cold storage tank is shown, the positive number shows cold discharging, and the negative number shows cold storage.

2. The bus architecture based modeling method of energy distributor as claimed in claim 1, wherein: in the step 1), the power-power bus interface model integrates a transformer, photovoltaic power generation, fan power generation and a storage battery, the transformer is mainly used for being connected into an external large power grid, whether the transformer operates or not determines the working state of the energy distributor, and when the energy distributor is in a networking state, the transformer and the external power grid interact to realize stabilization of renewable energy; when the energy distributor is in an island state, the storage battery is used for stabilizing fluctuation generated by solar energy and fan power generation, and simultaneously plays a role in peak clipping and valley filling.

3. The modeling method of the bus-based structure energy distributor as claimed in claim 1, wherein: in the step 1), the electric power-thermal power bus interface model integrates an electric boiler, a heat pump and a heat storage tank, and when the central heating system cannot provide enough heat source and the electric power is surplus, the electric boiler or the heat pump is started to convert a part of electric energy into heat energy so as to make up for short-time insufficient heat energy supply; the heat storage tank is used for realizing peak shifting adjustment of electric power and heating power, and is key equipment for translating heat loads.

4. The bus architecture based modeling method of energy distributor as claimed in claim 1, wherein: in the step 1), the electric power-cold power bus interface model integrates the electric refrigerator and the cold storage tank.

5. The bus architecture based modeling method of energy distributor as claimed in claim 1, wherein: in the step 1), the electric power-natural gas bus interface model mainly integrates electric power conversion equipment and a gas storage tank.

6. The modeling method of the bus-based structure energy distributor as claimed in claim 1, wherein: in the step 1), the natural gas-thermal bus interface model integrates a gas type cogeneration unit, a gas boiler, a gas storage tank and a heat storage tank.

7. The bus architecture based modeling method of energy distributor as claimed in claim 1, wherein: in the step 1), the heating power-cooling power bus interface model integrates an absorption refrigerator and a cold storage tank.

8. The bus architecture based modeling method of energy distributor as claimed in claim 1, wherein: the step 2) specifically comprises the following steps: and according to the specific requirements of actual users on the type and the quantity of energy, reasonably selecting and combining a plurality of bus type interface models to finally obtain the reasonable type, the quantity and the topological structure of the energy conversion devices in the energy distributor.

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