CN103515980A - Energy management method for micro-grid containing ground source heat pump - Google Patents

Abstract

The invention discloses a microgrid energy management method including a ground source heat pump, which includes two time scale modes of day-ahead control plan and real-time correction control, and can formulate different strategies according to various optimization objectives and constraint conditions. The method includes the following steps: formulating a day-ahead scheduling control strategy according to the photovoltaic power generation and load daily forecast curve; revising the daily scheduling plan formulated by the day-ahead scheduling control according to the current real-time operation of the system and the energy storage state. The present invention optimizes the energy management of the micro-grid with ground source heat pumps on multiple time scales, and the system operation controller executes various optimization control and energy management sub-strategies according to the dispatching instructions of the monitoring system and in combination with the current real-time operation status of the system. The energy management method provided by the invention can effectively improve the operation reliability of the microgrid including the ground source heat pump, and reduce the impact on the microgrid when the ground source heat pump is started.

Description

Energy management method of microgrid with ground source heat pump

technical field

The invention belongs to the technical field of renewable energy power generation and microgrid application, and relates to a microgrid energy management control method, in particular to a microgrid multi-time scale energy management method including a ground source heat pump.

Background technique

With the depletion of fossil fuels and the increasing environmental pollution, distributed power generation has been more and more widely used. Microgrid effectively integrates distributed power generation, energy storage, and load through control means, and provides a flexible and efficient platform for the utilization of distributed power generation technology. It has received widespread attention in recent years.

The energy management system of the microgrid is the basis for realizing the stable operation of the microgrid. The micro-grid energy management system collects real-time operation data of the micro-grid and issues control instructions to each component of the micro-grid according to the established operation control strategy, thereby ensuring the safe and stable operation of the micro-grid and realizing the coordination of distributed power generation, energy storage, and loads Operation and coordinated operation of microgrid and distribution network.

Due to the complexity and particularity of the load of the microgrid including the ground source heat pump, its energy management method must also be specially designed. Ground source heat pump is a high-efficiency, energy-saving and environment-friendly air-conditioning system that uses underground shallow geothermal resources to provide both heating and cooling. When it is started, the current will reach 4 to 7 times the rated current, which will have a certain impact on the power grid. Especially when the microgrid operates off-grid. If the ground source heat pump is not controlled during start-up, the power of the micro-grid will fluctuate and the power grid will lose stability. Not only will the power load fail to start successfully, but the micro-grid may also collapse.

In order to ensure the stable operation of the microgrid with ground source heat pump, reduce its adverse impact on the distribution network, and ensure that it can be successfully started when off-grid, it is necessary to design an energy management method for the microgrid with ground source heat pump.

The Chinese patent "Multi-time-scale Energy Optimal Scheduling Method for Micro-grid in Independent Operation Mode" with application number 201110191474.5 provides a multi-time-scale energy optimal dispatch method for micro-grid in independent operation mode, which divides the economic operation of micro-grid into There are two stages of day-ahead planning and real-time scheduling. In the day-ahead planning stage, a scheduling cycle is divided into 24 periods. Based on the day-ahead forecast data, an optimization calculation model for the start-up and shutdown of day-ahead units is established; The shutdown results are based on real-time ultra-short-term forecast data and real-time monitoring of the energy state of the energy storage unit. Different energy optimizations are adopted according to the size of the net load and the different energy state intervals of the energy storage unit to determine the power of each controllable micro power supply. Active power scheduling command, unloading power command and load shedding command. However, the control method proposed in this patent is limited to the independent operation of the microgrid, and does not include the grid-connected operation of the microgrid; moreover, the load of the microgrid in this patent is a conventional load, not a rotating load with ground source heat pumps as described in this article. Load, there is no current impact when the microgrid starts off-grid, so its control method is relatively simple.

Contents of the invention

The purpose of the present invention is to provide an energy management method for a microgrid including a ground source heat pump, so that the microgrid can maintain stable operation of the system when the ground source heat pump starts and works normally.

In order to achieve the above object, the present invention adopts following technical scheme, and it comprises the following steps:

1) Collect weather information data and load information data of the microgrid, integrate the historical solar energy/wind energy/load of the operation of the microgrid to predict the future day, and obtain the solar energy/wind energy/load forecast data of the microgrid in the next day;

2) Considering the output limitation and operating status of each equipment component in the microgrid, based on the solar/wind energy/load forecast data of the microgrid in the next day in step 1), formulate the distributed power supply and energy storage in the microgrid for 24 hours the next day And the energy management plan of the load, and send it to the microgrid energy management system one day in advance;

3) The microgrid implements the energy management plan formulated the previous day, and monitors the system operation and energy storage status in real time to determine whether the energy management plan formulated the previous day is met. The situation is corrected;

4) According to step 3), the control command of the microgrid containing the ground source heat pump is obtained, and issued to the adjustable distributed power supply, energy storage device and load controller in the microgrid, so that the microgrid will be stable in the next period according to the formulated energy management plan run.

The beneficial effect that the present invention reaches:

The method of the present invention divides the energy management of the microgrid into two parts: the day-ahead control plan and the real-time correction control. The long-term day-ahead control plan can reduce the impact of the start-up of the ground source heat pump on the microgrid and ensure the safe and stable operation of the system; The real-time correction control considers the real-time operation of the microgrid including the ground source heat pump, and takes into account the safety and stability of the microgrid operation.

Description of drawings

Fig. 1 is a block diagram of the energy management control method of the microgrid containing the ground source heat pump according to the present invention;

Fig. 2 is a schematic diagram of the microgrid system of the present invention.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings. The following examples are only used to illustrate the technical solution of the present invention more clearly, but not to limit the protection scope of the present invention.

According to the control type, the present invention divides the power sources in the microgrid into three categories: adjustable distributed power sources, non-adjustable distributed power sources and energy storage. Among them, adjustable distributed power includes gas turbines, photovoltaic power generation with linearly adjustable output power, etc.; non-adjustable distributed power includes wind power, etc.

As shown in Figure 1, the implementation steps of the multi-time-scale energy management method of the microgrid including the ground source heat pump of the present invention are as follows:

1. Collect microgrid load information data and meteorological information data, integrate historical data of microgrid operation, predict load/wind energy/solar energy for the next day, and obtain 24-hour microgrid load/wind energy/solar energy forecast data in the next day. Divide a day into time periods, where forecast data includes:

(1) The short-term output forecast curve of distributed power generation 24 hours a day in the future scheduling cycle (the next day), including P _Ci means that the output power of distributed power generation can be adjusted in the i-th period, and P _UCi means that the i-th time period is not adjustable distributed power output power);

(2) Short-term load forecast curve for 24 hours a day in the future scheduling cycle (the next day) ( _PLDi represents the load consumption power of the i-th period);

(3) The maximum possible charging and discharging power of the energy storage at the corresponding moment (P _Bicmaxi represents the maximum discharge power of the energy storage in the i-th period, P _Bcmaxi represents the maximum possible charging power of the energy storage in the i-th period, a positive number represents the energy storage discharge, and a negative number represents the energy storage charge ).

2. Combined with the 24-hour dispatching plan of the distribution network in the future dispatching cycle (the next day) and the output constraints of each equipment component in the micro-grid, formulate the adjustable distributed power supply, load and energy storage of the micro-grid. Run the plan.

3. The micro-grid energy management system receives the micro-grid energy management plan issued by the distribution network, and executes the energy management plan according to the plan at different time periods to ensure the safe and stable operation of the micro-grid.

4. During the set adjustment cycle, the microgrid energy management system monitors the microgrid’s operating status and compares it with the day-ahead control plan to determine whether the current real-time operating status of the microgrid meets the requirements of the energy management system.

5. If the current operation of the microgrid meets the requirements of the energy management system, it means that there is no need to adjust the output power of each distributed power source and energy storage in the microgrid through the energy management strategy in this adjustment cycle. Enter the next adjustment cycle after waiting for the end of the current adjustment cycle.

6. If the current operation of the microgrid does not meet the requirements of the energy management system, calculate the difference between the predicted data in step 1 and the real-time data, and formulate a real-time correction control strategy for the microgrid.

7. The microgrid energy management system sends the real-time correction control strategy to each adjustable distributed power source, energy storage and load, and the relevant control device realizes the power adjustment to meet the dispatching requirements.

8. Wait for the end of this adjustment cycle to enter the next adjustment cycle.

Example:

Consider the microgrid shown in Figure 2. The microgrid contains photovoltaic power generation systems, batteries, supercapacitors, ground source heat pumps, AC charging piles, and lighting. Among them, the photovoltaic power generation system is an adjustable distributed power supply; the energy storage device includes a battery and a super capacitor, the battery provides long-term energy supply, and the super capacitor provides short-term high-power energy; the load is ground source heat pump, AC charging pile and lighting. The battery energy state range is divided into: SOC _max = 0.8, SOC _max = 0.2; the invention is used to manage the energy of the microgrid including the ground source heat pump.

1. Collect microgrid load information data and weather information data, integrate historical data of microgrid operation, predict load/solar energy for the next day, and obtain 24-hour microgrid load/solar energy forecast data for the next day.

2. Taking 1 hour as a period, divide the operation of the microgrid into 24 periods in the future, take the operating cost of the microgrid throughout the day as the objective function, and consider the energy balance of each period within the microgrid and the output constraints of each equipment component , based on the day-ahead load/solar energy forecast data in step 1, the operation planning scheme of photovoltaic power generation system, energy storage system and load in each period will be obtained.

3. During the real-time operation of the microgrid, every 20 minutes is an operation cycle, that is, every hour is divided into 3 operation periods, and the whole day is divided into nT=24*3=72 planned operation periods. At each scheduling time Monitor the output power of the photovoltaic power generation system, the energy state SOC and output of the energy storage unit, and the load condition.

4. According to the operation status of the photovoltaic power generation system, energy storage system and load in the real-time microgrid system obtained in step 3, compare with the operation plan obtained in step 2 to obtain the operation difference of each equipment component, and establish the optimal operation model. The economic operation scheme of the microgrid in this period is obtained by solving the problem.

5. According to the micro-grid economic operation plan obtained in step 4, the micro-grid operation command is formed, and issued to the adjustable distributed power supply, energy storage device and load in the micro-grid, so that the micro-grid can operate safely according to the specified method in the next period.

6. At the next scheduling time, judge whether the 24th time period has been reached, if not, repeat step 4, if yes, repeat step 1.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them, although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: it can still be Modifications or equivalent replacements are made to the technical solution of the present invention, and these modifications or equivalent replacements cannot make the modified technical solution deviate from the spirit and scope of the technical solution of the present invention.

Claims (6)

1. A microgrid energy management method comprising a ground source heat pump, characterized in that: comprising the following steps: 1) First, by collecting microgrid load information data and meteorological information data, and integrating historical microgrid operating data, the solar energy/wind energy/load is forecasted for the next day, and the 24-hour distributed power supply of the microgrid in the future scheduling cycle is obtained. , energy storage and load forecast data, combined with the dispatch plan of the 24-hour distribution network in the future dispatch cycle, formulate the energy management plan of the microgrid today; 2) Considering the output limitation and operating status of each equipment component in the microgrid, based on the solar/wind energy/load forecast data of the microgrid in the next day in step 1), formulate the distributed power supply and energy storage in the microgrid for 24 hours the next day And the energy management plan of the load, and send it to the microgrid energy management system one day in advance; 3) The microgrid implements the energy management plan formulated the previous day, and monitors the system operation and energy storage status in real time to determine whether the energy management plan formulated the previous day is met. The control strategy is revised; 4) According to step 3), the scheduling instruction of the microgrid containing the ground source heat pump is obtained, and issued to the adjustable distributed power supply, energy storage device and load controller in the microgrid, so that the microgrid will be stable in the next period according to the formulated energy management plan run. 2. The microgrid energy management method comprising a ground source heat pump according to claim 1, characterized in that: the predicted data of the microgrid comprises: The predicted value curve of distributed power generation output 24 hours a day in the future dispatching cycle, including the adjustable distributed power generation output power P _Ci in the i-th time period, and the non-adjustable distributed power generation output power P _UCi in the i-th time period; 24-hour load short-term forecast curve in the future scheduling cycle, including load consumption power P _LDi in the i-th period; The maximum possible charge and discharge power of the energy storage at the corresponding moment includes the maximum discharge power P _Bicmaxi of the energy storage in the i-th period and the maximum possible charge power P _Bcmaxi of the energy storage in the i-th period. 3. The microgrid energy management method including ground source heat pump according to claim 1, characterized in that: in the step 3), within the set adjustment cycle, the microgrid energy management system monitors the microgrid The operation status of distributed power supply, energy storage and load can be adjusted internally, and the current real-time operation status of the microgrid can be obtained; the current real-time real-time operation status of the microgrid is compared with the energy management plan issued by the distribution network to determine the current status of the microgrid. Whether the real-time operation meets the requirements of the microgrid energy management plan. 4. The microgrid energy management method containing ground source heat pump according to claim 3, characterized in that: If the current real-time operation of the microgrid satisfies the day-ahead energy management plan, wait for the end of this regulation cycle to enter the next regulation cycle; If the current real-time operation of the microgrid does not meet the requirements of the energy management system plan, calculate the difference between the predicted data and the real-time data, and formulate a real-time correction control strategy for the microgrid to meet the requirements of the energy management plan. 5. The microgrid energy management method including ground source heat pump according to claim 4, characterized in that: the step of adjusting the output power of each power supply in the microgrid by the microgrid energy management system is: According to the real-time operation of the micro-grid and the power limit of each device, formulate a real-time correction control strategy for the micro-grid; The real-time correction control requirements of the microgrid are sent to the adjustable distributed power supply, energy storage and adjustable load in the microgrid, and the output power is adjusted by the corresponding control device. 6. The microgrid energy management method including a ground source heat pump according to claim 5, characterized in that: when the microgrid energy management system adjusts the output power of each power supply in the microgrid, the adjustable distributed power supply is adjusted according to the priority, Then adjust the energy storage, finally adjust the load and switch non-adjustable distributed power in this order. the

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