CN115864484A - Power and Energy Control Method of Multi-energy Complementary DC Microgrid - Google Patents

Abstract

The present invention provides a power energy control method for a multi-energy complementary DC microgrid, which includes: during the valley period of electricity consumption, when the daily average power generated by new energy sources is greater than K1 times the average daily power consumption of loads, the two-way DC to DC The unit outputs power to the load; when the daily average power generated by the new energy source is less than K1 times the average daily power consumption of the load, the bidirectional DC-to-DC unit charges the energy storage battery; The DC-to-DC unit outputs power to the load; during the peak period of power consumption, the bidirectional DC-to-DC unit outputs power to the load; wherein, K1 is a real number greater than 0. The power and energy control method of the multi-energy complementary DC micro-grid of the present invention can not only maintain the power and energy balance in the DC micro-grid, but also respond to the demand for peak regulation of the power grid, and further reduce the cost of electricity; at the same time, it maximizes the use of new energy, so that from The total electricity consumed by the grid is greatly reduced, reducing carbon emissions.

Description

Power and Energy Control Method of Multi-energy Complementary DC Microgrid

technical field

The invention relates to the field of power supplies, in particular to a power energy control method of a multi-energy complementary DC microgrid.

Background technique

In the topology of the DC microgrid, the DC/DC bidirectional energy storage converter and the DC/DC photovoltaic MPPT charger are connected in parallel through the DC bus. According to the change amount ΔUdc of the DC bus voltage, the control strategy can be divided into different control layers, and the working mode of each converter is adjusted correspondingly under each control layer to ensure the power balance in the network. Each DC/DC regulates the bus voltage through droop control, and the battery plays the role of balancing the power and energy flow in the DC microgrid, but lacks the response to the demand side of the grid.

How to further exert the peak-shifting ability of the energy storage unit to the power grid in the distributed power generation system, and balance the power and energy flow in the DC micro-grid under various working conditions, so as to achieve near-zero carbon emissions is an urgent need to solve in the industry one of the problems.

Contents of the invention

In view of the shortcomings of the prior art described above, the purpose of the present invention is to provide a power energy control method for a multi-energy complementary DC micro-grid, which is used to solve the problem that the energy storage unit in the prior art cannot take into account the peak-staggered regulation of the power grid and the balance of the DC micro-grid. The problem of grid power energy flow.

In order to achieve the above purpose and other related purposes, the present invention provides a power energy control method of a multi-energy complementary DC micro-grid, the multi-energy complementary DC micro-grid includes an AC to DC unit, at least one new energy power generation device, and an energy storage battery . A bidirectional DC-to-DC unit, the power energy control method of the multi-energy complementary DC microgrid at least includes:

During the trough period of electricity consumption, when the daily average power generated by the new energy is greater than K1 times the average daily power consumption of the load, the bidirectional DC-to-DC unit outputs power to the load; when the daily average power generated by the new energy is less than K1 times When the load consumes average daily power, the bidirectional DC-to-DC unit charges the energy storage battery;

During the undulating period of power consumption, the bidirectional DC-to-DC unit outputs power to the load;

During the peak period of power consumption, the bidirectional DC-to-DC unit outputs power to the load;

Wherein, K1 is a real number greater than 0.

Optionally, the method for judging the relationship between the daily average power generated by the new energy source and the daily average power consumption of loads K1 times includes:

If the cumulative power generation of the new energy on the day is greater than K1 times the cumulative power consumption of the load on the day, it is judged that the daily average power generated by the new energy is greater than the average daily power consumption of the load by K1 times; otherwise, it is judged that the daily average power generated by the new energy is less than K1 times the daily average power consumption of the load.

Optionally, the method for judging the relationship between the daily average power generated by the new energy source and the daily average power consumption of loads K1 times includes:

During peak hours and flat periods of electricity consumption, when the real-time power generated by the new energy is greater than K2 times the real-time power consumption of the load, the timer will be self-increased;

If the timing result of the timer is greater than or equal to the preset time, it is judged that the daily average power generation of the new energy is greater than K1 times the average daily power consumption of the load; otherwise, it is judged that the daily average power generation of the new energy is less than K1 times the load Daily average power consumption;

Wherein, K2 is a real number greater than 0.

More optionally, during trough periods of electricity usage:

When the daily average power generated by the new energy is greater than K1 times the average daily power consumption of the load, if the remaining power of the energy storage battery is greater than the first set power, the bidirectional DC-to-DC unit outputs power to the load , and the output power of the bidirectional DC-to-DC unit is the preset output power of the energy storage battery;

When the daily average power generated by the new energy source is less than K1 times the daily average power consumption of the load, and if the remaining power of the energy storage battery is less than the upper limit of power, the bidirectional DC-to-DC unit charges the energy storage battery.

More optionally, during periods of flat electricity usage:

When the new energy real-time power generation power is less than or equal to K2 times the load real-time power consumption, and the new energy daily average power generation power is greater than K1 times the load daily average power consumption, the output power of the bidirectional DC-to-DC unit is a preset value ;

When the real-time power generated by the new energy is less than or equal to K2 times the real-time power consumption of the load, and the daily average power generated by the new energy is less than the daily average power consumption of the load K1 times, the output power of the bidirectional DC-to-DC unit is based on the Describe the real-time power generation changes of new energy sources;

When the real-time power generated by the new energy source is greater than K2 times the real-time power consumption of the load, the output power of the bidirectional DC-to-DC unit changes according to the real-time power consumption of the load;

Wherein, K2 is a real number greater than 0.

More optionally, during periods of flat electricity usage:

When the real-time power generated by the new energy is less than or equal to K2 times the real-time power consumption of the load, and the daily average power generated by the new energy is greater than the daily average power consumption of the load K1 times, the energy storage battery passes the bidirectional DC to DC The unit outputs power to the load; at this time, if the real-time power consumption of the load is greater than the preset output power of the energy storage battery, the output power of the bidirectional DC-to-DC unit is the preset output power of the energy storage battery ; If the real-time power consumption of the load is less than or equal to the preset output power of the energy storage battery, the output power of the bidirectional DC-to-DC unit is zero or alternate output power;

When the real-time power generated by the new energy is less than or equal to K2 times the real-time power consumption of the load, and the daily average power generated by the new energy is less than the daily average power consumption of the load K1 times, the new energy power generation device passes the two-way DC converter The DC unit outputs power to the load, and the output power of the bidirectional DC-to-DC unit is K3 times the new energy real-time power generation power;

When the real-time power generated by the new energy source is greater than K2 times the real-time power consumption of the load, the bidirectional DC-to-DC unit outputs power to the load, and the output power of the bidirectional DC-to-DC unit is K4 times the real-time power consumption of the load;

Wherein, both K3 and K4 are real numbers greater than 0.

More optionally, when the new energy real-time power generation power is less than or equal to K2 times the load real-time power consumption, and the new energy daily average power generation power is greater than K1 times the load daily average power consumption, if the remaining power of the energy storage battery If it is greater than the second set power, the energy storage battery outputs power to the load through the bidirectional DC-to-DC unit; if the remaining power of the energy storage battery is less than or equal to the second set power, the bidirectional DC-to-DC The output power of the unit is zero.

Optionally, during peak hours of electricity use:

When the new energy real-time power generation is greater than the preset power generation, if the real-time power consumption of the load is greater than the rated output power of the bidirectional DC-to-DC unit, the output power of the bidirectional DC-to-DC unit is the preset output of the energy storage battery The sum of the power and the real-time power generated by the new energy; if the real-time power consumption of the load is less than the minimum output power of the bidirectional DC-to-DC unit, the output power of the bidirectional DC-to-DC unit is the minimum output power or the output power is zero ; Otherwise, the output power of the bidirectional DC-to-DC unit is K5 times the real-time power consumption of the load;

When the real-time generated power of the new energy is less than or equal to the preset generated power, if the real-time power consumption of the load is greater than the preset output power of the energy storage battery, the output power of the bidirectional DC-to-DC unit is equal to that of the storage battery. The preset output power of the energy storage battery; if the real-time power consumption of the load is less than or equal to the preset output power of the energy storage battery, the output power of the bidirectional DC-to-DC unit is zero or alternate output power;

Among them, K5 is a real number.

More optionally, when the real-time power generated by the new energy is greater than the preset power, or the real-time power generated by the new energy is less than or equal to the preset power and the real-time power consumption of the load is greater than the preset output power of the energy storage battery , if the remaining power of any energy storage battery is less than the first preset power, the output power of the bidirectional DC-to-DC unit corresponding to the road is zero.

More optionally, the output power of the bidirectional DC-to-DC unit is zero or the alternate output power includes: the bidirectional DC-to-DC unit is set in N groups, if N=1, the output of the bidirectional DC-to-DC unit The power is zero; if N is an integer greater than or equal to 2, then N groups of bidirectional DC-to-DC units alternately output power to the load in time-sharing. At this time, the remaining power of the energy storage battery corresponding to each bidirectional DC-to-DC unit is periodically Carry out the calculation, and select the output power of M groups of bidirectional DC-to-DC units with relatively large remaining power of the energy storage battery, and the output power of each bidirectional DC-to-DC unit is 1/N of the preset output power of the energy storage battery, M is an integer greater than or equal to 1 and less than N.

More optionally, the multi-energy complementary DC micro-grid is also equipped with AC power consumption equipment. When the daily average power generation of the new energy source is less than K1 times the load daily average power consumption, and the AC power grid is normal, the The AC grid supplies power to the AC power equipment; otherwise, the DC bus supplies power to the AC power equipment through the DC-to-AC unit.

As mentioned above, the power energy control method of the multi-energy complementary DC microgrid of the present invention has the following beneficial effects:

1. The power energy control method of the multi-energy complementary DC micro-grid of the present invention controls the charging and discharging direction of the DC/DC bidirectional DC-to-DC unit according to the peak-valley electricity price when the average power generation of new energy is less than the average power consumption of the load, and combines The power generated by new energy sources supplies power to the load. It can not only maintain the power and energy balance in the DC microgrid, but also respond to the demand for peak regulation of the power grid, further reducing the cost of electricity consumption.

2. The power energy control method of the multi-energy complementary DC microgrid of the present invention controls the charging and discharging of the DC/DC bidirectional DC-to-DC unit when the average power generation of the new energy is greater than the average power consumption of the load. At the peak time, the new energy DC /DC (that is, MPPT) charges the energy storage battery and supplies power to the load, and when the new energy power generation is weak at the time of wave level, the energy storage battery and AC/DC (AC to DC unit) discharge the load together, so that the total power consumed is drawn from the grid Greatly reduce, but more use of natural energy, reduce carbon emissions.

3. The power energy control method of the multi-energy complementary DC micro-grid of the present invention provides power for the air conditioner in the system through the DC bus when the average power generation of the new energy is greater than the average power consumption of the load, so that the total power drawn from the power grid is greatly reduced. Small, but more use of natural energy, reducing carbon emissions.

Description of drawings

Fig. 1 shows a schematic structural diagram of the multi-energy complementary direct current microgrid of the present invention.

Fig. 2 is another structural schematic diagram of the multi-energy complementary DC microgrid of the present invention.

Component designation description

1 Multi-energy complementary DC microgrid

11 New energy power generation device

12 Energy storage battery

13 Bidirectional DC to DC unit

14 DC to AC unit

15 First AC contactor

16 Second AC contactor

17 AC power equipment

18 AC to DC unit

19 DC power equipment

Detailed ways

Embodiments of the present invention are described below through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation modes, and various modifications or changes can be made to the details in this specification based on different viewpoints and applications without departing from the spirit of the present invention.

Please refer to Figures 1 to 2. It should be noted that the diagrams provided in this embodiment are only schematically illustrating the basic idea of the present invention, and only the components related to the present invention are shown in the diagrams rather than the number, shape and shape of components in real-time implementation. Dimensional drawing, the type, quantity and proportion of each component can be changed arbitrarily during real-time implementation, and the component layout type may also be more complex.

The present invention provides a power energy control method of a multi-energy complementary DC microgrid, which is realized based on a multi-energy complementary DC microgrid 1, and the multi-energy complementary DC microgrid 1 includes an AC-to-DC unit 18 and at least one new energy power generation device 11 , an energy storage battery 12, and a bidirectional DC-to-DC unit 13.

As shown in Figure 1, as an implementation of the present invention, the multi-energy complementary DC microgrid 1 includes an AC-to-DC unit 18, N new energy power generation devices 11, N energy storage batteries 12 and N bidirectional DC Converting DC unit 13, N is an integer greater than or equal to 1; the input end of the AC converting DC unit 18 is connected to the AC power grid AC, and the output end is connected to the DC bus BUS to convert the AC power in the AC power grid AC into DC power and provide For the DC bus; a new energy generating device 11, an energy storage battery 12 and a bidirectional DC-to-DC unit 13 form a group. When N is greater than or equal to 2, N groups are connected in parallel on the DC bus BUS. In each group, the new energy generating device 11 generates electric energy based on new energy, and the new energy generating device 11 includes but is not limited to solar cells and/or wind power generating devices; the new energy generating device 11 includes a power generating device and a control unit, as an example, the control unit is a maximum power point tracker (MPPT, Maximum Power Point Tracking). The energy storage battery 12 is connected to the output terminal of the new energy power generation device 11 for storing electric energy; as an example, the positive pole of the energy storage battery 12 is connected to the positive pole of the battery output terminal of the new energy power generation device 11, and the negative pole is connected to The battery output terminal of the new energy power generation device 11 is negative. One end of the bidirectional DC-to-DC unit 13 is connected to the output end of the new energy power generation device 11, and the other end is connected to the DC bus BUS for realizing bidirectional energy transfer between the energy storage battery 12 and the DC bus BUS. Conversion; as an example, the positive pole of the battery input and output terminal of the bidirectional DC-to-DC unit 13 is connected to the positive pole of the energy storage battery 12, the negative pole of the battery input and output terminal is connected to the negative pole of the energy storage battery 12, and the positive pole of the bus input and output terminal is connected to The positive pole of the direct current bus BUS, and the negative pole of the input and output terminals of the bus are connected to the negative pole of the direct current bus BUS.

As shown in Figure 2, as another implementation of the present invention, the multi-energy complementary DC microgrid 1 includes N1 new energy power generation devices 11, N2 energy storage batteries 12 and N2 bidirectional DC-to-DC units 13, Both N1 and N2 are integers greater than or equal to 1; the output terminals of each new energy generating device 11 are directly connected to the DC bus BUS, an energy storage battery 12 and a bidirectional DC-to-DC unit 13 form a group, when N2 is greater than or equal to 2, the N2 group is connected in parallel on the DC bus BUS. Wherein, one end of the bidirectional DC-to-DC unit 13 is connected to the energy storage battery 12, and the other end is connected to the DC bus BUS for realizing bidirectional energy conversion between the energy storage battery 12 and the DC bus BUS .

It should be noted that, in actual use, the numbers of the new energy generating device 11, the energy storage battery 12, and the bidirectional DC-to-DC unit 13 can be set according to the specific topology, and will not be repeated here. A load is also connected to the DC bus BUS, and the load includes a DC load and/or an AC load. In this example, the load is a DC electrical device 19 , which will not be repeated here.

The invention controls the power energy of the DC microgrid based on the relationship between the new energy power generation power and the load consumption power in different power consumption periods, and optimizes the charging and discharging process by considering the difference in electricity prices in different periods. As an example, peak hours include: peak hour: 20:00-22:00 (total 2 hours) and peak hour: 9:00-15:00 (total 6 hours), electric wave flat period includes: 7:00 -9:00, 15:00-20:00, 22:00-23:00 (total 8 hours), power consumption valley period includes: 23:00-next day 7:00 (total 8 hours); The electricity price is also different, peak hour electricity price = basic electricity price × 180% + government funds and surcharges, peak hour electricity price = basic electricity price × 149% + government funds and surcharges, wave period electricity price = basic electricity price + government funds and surcharges, Electricity price during the valley period = basic electricity price × 48% + government funds and surcharges.

The multi-energy complementary DC microgrid power energy control method of the present invention includes:

During the trough period of electricity consumption, when the daily average power generated by the new energy is greater than K1 times the average daily power consumption of the load, the bidirectional DC-to-DC unit 13 outputs power to the load; when the daily average power generated by the new energy is less than K1 times When the daily average power consumption of the load, the bidirectional DC-to-DC unit 13 charges the energy storage battery 12;

During the undulating period of power consumption, the bidirectional DC-to-DC unit 13 outputs power to the load;

During the peak period of power consumption, the bidirectional DC-to-DC unit 13 outputs power to the load.

It should be noted that K1 is a real number greater than 0, and its value range can be set according to requirements; in this embodiment, the value range of K1 is 0.5-2, preferably 0.9.

Specifically, as an example, the method for judging the relationship between the daily average power generation of the new energy source and the daily average power consumption of loads K1 times includes:

11) During the peak and flat periods of electricity consumption, when the real-time power generated by the new energy is greater than the real-time power consumption of the load that is K2 times, the timer is automatically incremented.

More specifically, in this embodiment, the counting range of the timer is 0 to h hours, that is, the upper limit of self-increment of the timer is h hours, and the lower limit of self-decrement is 0 hours. The value of h is set according to the preset time in K2 and step 112). As an example, h is set to 5 hours, that is, the real-time generating power of the new energy is greater than The real-time power consumption time of the load of K2 times is counted, and the timer is accumulated up to 5 hours, and no longer counts when it reaches 5 hours. In actual use, the timer may also not have a timing range, which is not limited to this embodiment.

More specifically, K2 is a real number greater than 0, and its value is set according to requirements. In this embodiment, the value range of K2 is set to 0.5-1.5, preferably 0.9.

More specifically, in this example, in order to realize the judgment of the relationship between the daily average power generation of new energy sources and the daily average power consumption of loads K1 times, the timer is reset at a preset time point every day, and the preset The time point is between the end of the peak period and the level period of the current day and before the start of the level period of the next day. As an example, the preset time point is the transition moment from the trough period to the level period, that is, at 7:00 in the morning, the timer is reset.

12) If the timing result of the timer is greater than or equal to the preset time, it is judged that the daily average power generation power of the new energy source is greater than K1 times the average daily power consumption of the load; otherwise, it is judged that the daily average power generation power of the new energy source is less than K1 times The daily average power consumption of the load.

More specifically, after the end of the electricity consumption peak period and the peak period of the day, the timing results of the timer are counted; in this embodiment, the statistical time of the timing results is set to the current day: 23:00-24: between 00. In actual use, the definition of a day is not strictly limited to 0:00~24:00, the specific time point can be slightly deviated, and it is sufficient to ensure that a day is 24 hours. Therefore, the statistical time of the counting results can be slightly later than 24:00: 00 or slightly earlier than 24:00, so I won’t repeat them here.

More specifically, the preset time is set based on actual needs. As an example, the preset time is set to 3.5 hours.

It should be noted that, as another implementation of this example, in step 111) during the peak period of power consumption, when the real-time power generated by the new energy source is less than or equal to the real-time power consumption of the load and greater than the preset power generation , the timer is decremented. The preset generating power can be set according to needs. In this embodiment, the preset generating power is set to 500W; in actual use, the preset generating power includes but not limited to 450W, 470W, 480W, 510W and 530W. As an example, taking the new energy power generation device 11 as a photovoltaic example, when the real-time photovoltaic power generation power is greater than or equal to 500W, it is judged that there is light, and photovoltaic power generation can be realized; At 500W, it is judged that the wind power is greater than level 3, and wind power generation can be realized.

Specifically, as another example, the method for judging the relationship between the daily average power generation of new energy sources and the daily average power consumption of loads K1 times includes:

If the cumulative power generation of the new energy on the day is greater than K1 times the cumulative power consumption of the load on the day, it is judged that the daily average power generated by the new energy is greater than the average daily power consumption of the load by K1 times; otherwise, it is judged that the daily average power generated by the new energy is less than K1 times the daily average power consumption of the load.

It should be noted that the method for judging the relationship between the daily average power generation of the new energy and the daily average power consumption of the load that is K1 times is not limited to the methods listed in this embodiment, any method that can achieve the daily average power generation of the new energy and The methods for judging the magnitude relationship of K1 times the daily average power consumption of the load are applicable to the present invention, including but not limited to calculating and comparing the daily average power generation power of the new energy source and the daily average power consumption of the load, which will not be repeated here. In addition, in the present invention, the daily average power consumption of loads whose daily average generating power of new energy is greater than or less than K1 times is only two self-defined judgment conditions, not the actual working conditions.

The power and energy control methods for different power consumption periods will be described respectively below.

During the valley period of electricity consumption:

21) When the average daily power generated by the new energy source is greater than K1 times the average daily power consumption of the load, and if the remaining power of the energy storage battery 12 is greater than the first set power, the bidirectional DC-to-DC unit 13 will power the The load output power, and the output power of the bidirectional DC-to-DC unit 13 is the preset output power of the energy storage battery 12 .

Specifically, as an example, the first set electric quantity is set to 65% of the capacity of the energy storage battery 12; limit. If the remaining power of the energy storage battery 12 is greater than 65%, the energy storage battery 12 is discharged, and based on the bidirectional DC-to-DC unit 13 to output power to the load; discharge to the remaining power of the energy storage battery 12 When the electricity is 65%, the energy storage battery 12 stops discharging. During this process, even if the remaining power of the energy storage battery 12 is less than 65%, the bidirectional DC-to-DC unit 13 will not charge the energy storage battery 12 any more.

22) When the daily average power generated by the new energy source is less than K1 times the daily average power consumption of the load, if the remaining power of the energy storage battery 12 is less than the upper limit of power, the bidirectional DC-to-DC unit 13 will supply the energy storage The battery 12 is charged.

Specifically, as an example, the upper limit of the power is set to 95% to 100% of the capacity of the energy storage battery 12, preferably 100%; Examples are limited. If the remaining power of the energy storage battery 12 does not reach 100%, the AC-to-DC unit 18 supplies power to the DC bus BUS, and the voltage on the DC bus BUS is supplied to the DC bus BUS via the bidirectional DC-to-DC unit 13. The energy storage battery 12 is charged (that is, the energy storage battery 12 obtains electric energy from the AC grid AC); the charging is stopped when the remaining power of the energy storage battery 12 reaches 100%.

It should be noted that the remaining power of the energy storage battery 12 can be obtained based on including but not limited to the SOC of the energy storage battery 12 or the voltage of the energy storage battery 12 , which will not be repeated here.

During the wave period of electricity consumption:

31) When the new energy real-time power generation power is less than or equal to K2 times the load real-time power consumption, and the new energy daily average power generation power is greater than K1 times the load daily average power consumption, the output power of the bidirectional DC-to-DC unit 13 is default value.

Specifically, in this embodiment, when the real-time power generated by the new energy is less than or equal to K2 times the real-time power consumption of the load, and the daily average power generated by the new energy is greater than the daily average power consumption of the load K1 times, the energy storage battery 12 Output power to the load through the bidirectional DC-to-DC unit 13 . At this time, the output power of the bidirectional DC-to-DC unit 13 is determined based on the relationship between the preset output power of the energy storage battery 12 and the real-time power consumption of the load; if the real-time power consumption of the load is greater than that of the energy storage battery 12 preset output power, then the output power of the bidirectional DC-to-DC unit 13 is the preset output power of the energy storage battery 12 (at this time, the preset value is the preset output power of the energy storage battery 12 output power); if the real-time power consumption of the load is less than or equal to the preset output power of the energy storage battery 12, the output power of the bidirectional DC-to-DC unit 13 is zero or alternate output power.

More specifically, as an example, during this process, if the remaining power of the energy storage battery 12 is greater than the second set power, the energy storage battery 12 outputs power to the load through the bidirectional DC-to-DC unit 13; If the remaining power of the energy storage battery 12 is less than or equal to the second set power, the output power of the bidirectional DC-to-DC unit 13 is zero. The second set electric quantity is greater than the first set electric quantity and can be set according to actual needs. As an example, the second set electric quantity is set to 75% of the capacity of the energy storage battery 12 . If the remaining power of the energy storage battery 12 is greater than 75%, the energy storage battery 12 is discharged, and based on the bidirectional DC-to-DC unit 13 to output power to the load; discharge to the remaining power of the energy storage battery 12 When the electricity is 75%, the energy storage battery 12 stops discharging. During this process, even if the remaining power of the energy storage battery 12 is less than 75%, the bidirectional DC-to-DC unit 13 will not charge the energy storage battery 12 any more.

More specifically, as an example, when the real-time power generated by the new energy is less than or equal to K2 times the real-time power consumption of the load, and the daily average power generated by the new energy is greater than the daily average power consumption of the load K1 times, when the real-time consumption of the load When the power is less than the preset output power of the energy storage battery 12, if N=1, the output power of the bidirectional DC-to-DC unit 13 is zero (at this time, the preset value is zero). If N is an integer greater than or equal to 2, then N groups of bidirectional DC-to-DC units 13 alternately output power to the load in time divisions. The remaining power is calculated, and the output power of M groups of bidirectional DC-to-DC units 13 with a relatively large remaining power of the energy storage battery 12 is selected, and the output power of the remaining bidirectional DC-to-DC units 13 is zero, and the output of each bidirectional DC-to-DC unit 13 The power is 1/N of the preset output power of the energy storage battery 12, and M is an integer greater than or equal to 1 and less than N. In actual use, each energy storage battery 12 can also be discharged to the first set value in sequence, so as to realize the alternate output power of the bidirectional DC-to-DC unit 13; or calculate the remaining power of the energy storage battery 12, and use the remaining The energy storage batteries 12 whose power is greater than the second set value are sequentially discharged to the first set value, so as to realize the alternate output power of the bidirectional DC-to-DC unit 13; the present embodiment is not limited thereto.

More specifically, take N equal to 4 as an example; as an example, when the real-time power consumption of the load is greater than 0.5 times the preset output power of the energy storage battery 12, two bidirectional DC-to-DC units 13 give The output power of the load, the output power of each bidirectional DC-to-DC unit 13 is 1/4 of the preset output power of the energy storage battery 12, and the total output power of the two bidirectional DC-to-DC units 13 is the 1/2 of the preset output power of the energy storage battery 12 (at this time, the preset value is 1/2 of the preset output power of the energy storage battery 12), and the two-way DC to DC The time-sharing switching output in the unit 13, at this time M is equal to 2; when the real-time power consumption of the load is greater than 0.25 times the preset output power of the energy storage battery 12, it is given by one of the two-way DC-to-DC units 13 The load output power is 1/4 of the preset output power of the energy storage battery 12 (the total output power is also 1/4 of the preset output power of the energy storage battery 12, at this time, the The preset value is 1/4 of the preset output power of the energy storage battery 12, and the output is time-division switched in the four bidirectional DC-to-DC units 13, and M is equal to 1 at this time. By analogy, the output power of the bidirectional DC-to-DC unit 13 with a large remaining power of the energy storage battery 12 is preferred, so as to ensure that the output power of the new energy source is provided to the load to the greatest extent.

It should be noted that, in actual use, the fixed power output by the bidirectional DC-to-DC unit 13 can be set according to needs, and is not limited to this embodiment.

32) When the new energy real-time power generation power is less than or equal to K2 times the load real-time power consumption, and the new energy daily average power generation power is less than K1 times the load daily average power consumption, the output of the bidirectional DC-to-DC unit 13 The power changes according to the real-time power generation power of new energy sources.

It should be noted that the output power of the bidirectional DC-to-DC unit 13 is positively or negatively correlated with the real-time power generated by new energy sources, which is determined according to the topology of the actual multi-energy complementary DC microgrid 1 . In this embodiment, on the topological structure of FIG. 1, the output power of the bidirectional DC-to-DC unit 13 is positively correlated with the real-time power generated by the new energy; on the topological structure of FIG. 2, the bidirectional DC-to-DC The output power of the unit 13 is negatively correlated with the real-time power generated by the new energy; details will not be repeated here.

Specifically, as an example, on the basis of the topology in Figure 1, when the real-time power generated by the new energy is less than or equal to K2 times the real-time power consumption of the load, and the daily average power generated by the new energy is less than the daily average consumption of the load K1 times power, the new energy power generation device 11 outputs power to the load through the bidirectional DC-to-DC unit 13, and the output power of the bidirectional DC-to-DC unit 13 is K3 times the real-time power generated by the new energy.

More specifically, K3 is a real number greater than 0, and its value range can be set according to needs; in this embodiment, K3 is a real number slightly greater than 1, including but not limited to 1.2, 1.3, preferably 1.1.

33) When the real-time power generated by the new energy source is greater than K2 times the real-time power consumption of the load, the output power of the bidirectional DC-to-DC unit 13 changes according to the real-time power consumption of the load.

It should be noted that the output power of the bidirectional DC-to-DC unit 13 is positively or negatively correlated with the real-time power consumption of the load, which is determined according to the topology of the actual multi-energy complementary DC microgrid 1 . In this embodiment, on the topological structure of FIG. 1 , the output power of the bidirectional DC-to-DC unit 13 is positively correlated with the real-time power consumption of the load; on the topological structure of FIG. 2 , the bidirectional DC-to-DC unit The output power of 13 is negatively correlated with the real-time power consumption of the load; details will not be repeated here.

Specifically, in this embodiment, when the real-time power generated by the new energy source is greater than K2 times the real-time power consumption of the load, the bidirectional DC-to-DC unit 13 outputs power to the load, and the bidirectional DC-to-DC unit 13 The output power is K4 times the real-time power consumption of the load.

More specifically, as an example, on the basis of the topological structure in Figure 1, K4 is a real number greater than 0, and its value range can be set according to needs; in this embodiment, K4 is a real number slightly less than 1, including but not Limited to 0.8, 0.7, preferably 0.9.

During peak hours of electricity use:

41) When the new energy real-time power generation is greater than the preset power generation, if the real-time power consumption of the load is greater than the rated output power of the bidirectional DC-to-DC unit 13, the output power of the bidirectional DC-to-DC unit 13 is the energy storage battery The sum of the preset output power of 12 and the real-time power generated by new energy sources; if the real-time power consumption of the load is less than the minimum output power of the bidirectional DC-to-DC unit 13, the output power of the bidirectional DC-to-DC unit 13 is the minimum The output power or the output power is zero; otherwise, the output power of the bidirectional DC-to-DC unit 13 is K5 times the real-time power consumption of the load.

It should be noted that the output power of the bidirectional DC-to-DC unit 13 is positively or negatively correlated with the real-time power consumption of the load, which is determined according to the topology of the actual multi-energy complementary DC microgrid 1 . In this embodiment, on the topological structure of FIG. 1 , the output power of the bidirectional DC-to-DC unit 13 is positively correlated with the real-time power consumption of the load, that is, K5 is a real number greater than 0. As an example, K5 is slightly less than A real number of 1, including but not limited to 0.8, 0.7, preferably 0.9; in the topological structure of Figure 2, the output power of the bidirectional DC-to-DC unit 13 is negatively correlated with the real-time power consumption of the load; repeat.

Specifically, when the real-time power consumption of the load is greater than the rated output power of the bidirectional DC-to-DC unit 13, the power generated by the new energy generating device 11 is fully output, and the output power of the energy storage battery 12 is limited to a preset output power, so as to realize the limitation on the maximum output power of the bidirectional DC-to-DC unit 13 .

Specifically, when the real-time power consumption of the load is between the minimum output power of the bidirectional DC-DC unit 13 and the rated output power of the bidirectional DC-DC unit 13, the bidirectional DC-DC unit 13 The load whose output power is K5 times consumes power in real time.

Specifically, in this embodiment, when the real-time power generated by the new energy is greater than the preset power, if the remaining power of any energy storage battery 12 is less than the first preset power, the bidirectional DC-to-DC unit 13 of the corresponding road will output power is zero. At this time, the power generated by the new energy generating device 11 is used to charge the energy storage battery 12 to avoid deep discharge of the energy storage battery 12 , thereby increasing the service life of the energy storage battery 12 .

Specifically, as an example, for the topological structure of FIG. 1 , when the real-time power generated by the new energy is greater than the preset power, if the voltage of the energy storage battery 12 reaches the preset voltage, the new energy power generation device 11 will The mode of charging the energy storage battery 12 by the control unit is switched from maximum power tracking mode or equal charging mode to floating charging mode.

42) When the real-time generated power of the new energy is less than or equal to the preset generated power, if the real-time power consumption of the load is greater than the preset output power of the energy storage battery 12, the output power of the bidirectional DC-to-DC unit 13 is the preset output power of the energy storage battery 12; if the real-time power consumption of the load is less than or equal to the preset output power of the energy storage battery 12, the output power of the bidirectional DC-to-DC unit 13 is zero or alternatively Output Power.

Specifically, when the real-time power generated by the new energy source is less than or equal to the preset power generated and the real-time power consumption of the load is greater than the preset output power of the energy storage battery 12, if the remaining power of any energy storage battery 12 is less than the first A preset power level means that the output power of the bidirectional DC-to-DC unit 13 corresponding to the road is zero, so as to avoid deep discharge of the energy storage battery 12 and further increase the service life of the energy storage battery 12 .

Specifically, as an example, when the real-time power generated by the new energy source is less than or equal to the preset power generated, when the real-time power consumption of the load is less than the preset output power of the energy storage battery 12, if N=1, Then the output power of the bidirectional DC-to-DC unit 13 is zero. If N is an integer greater than or equal to 2, then N groups of bidirectional DC-to-DC units 13 alternately output power to the load in time division. The principle of timing alternate work is the same as that of the electric wave flat period, and will not be repeated here.

As shown in FIG. 1 and FIG. 2 , the multi-energy complementary DC microgrid 1 of the present invention also includes a DC-to-AC unit 14 , a first AC contactor 15 , a second AC contactor 16 and an AC power device 17 . The input end of the DC-to-AC unit 14 is connected to the DC bus BUS for converting the bus voltage into an AC voltage; the first AC contactor 15 is connected to the output end of the DC-to-AC unit 14 and the Between the power input terminals of the AC power equipment 17 ; the second AC contactor 16 is connected between the AC grid AC and the power input terminals of the AC power equipment 17 . When the daily average power generation of the new energy is less than K1 times the average daily power consumption of the load, and the AC grid AC is normal, the AC power supply 17 is supplied by the AC grid AC; The AC unit 14 supplies power to the AC electrical equipment 17 . The AC power equipment includes but is not limited to an air conditioner, and further, the air conditioner is used to control the temperature in the power supply cabinet of the base station.

Specifically, when the AC power grid AC is normal, if the average daily power generation of the new energy source is greater than K1 times the average daily power consumption of the load, the first AC contactor 15 is controlled to be closed, and the second AC contactor 16 is controlled to be closed. disconnected, at this time, the DC bus BUS is converted into an AC voltage by the DC-to-AC unit 14, and supplies power to the AC electrical equipment 17. Wherein, the DC bus BUS is powered by the AC-to-DC unit 18 , the new energy power generation device 11 , the energy storage battery 12 and the bidirectional DC-to-DC unit 13 . If the daily average power generation of the new energy is less than K1 times the daily average power consumption of the load, the first AC contactor 15 is controlled to be disconnected, and the second AC contactor 16 is closed. At this time, the AC grid AC is The AC electrical equipment 17 supplies power.

Specifically, when the AC power grid AC is abnormal, the first AC contactor 15 is controlled to be closed, and the second AC contactor 16 is disconnected. At this time, the DC bus BUS is converted into an AC voltage by the DC-to-AC unit 14 , and supply power to the AC electrical equipment 17. Among them, the DC bus BUS is powered by a new energy power generation device 11 , an energy storage battery 12 and a bidirectional DC-to-DC unit 13 .

To sum up, the present invention provides a power and energy control method for a multi-energy complementary DC microgrid, including: during the trough period of electricity consumption, when the daily average power generated by the new energy is greater than K1 times the average daily power consumption of the load, the The bidirectional DC-to-DC unit outputs power to the load; when the daily average power generated by the new energy source is less than K1 times the load’s daily average power consumption, the bidirectional DC-to-DC unit charges the energy storage battery; , the bidirectional DC-to-DC unit outputs power to the load; during the peak period of power consumption, the bidirectional DC-to-DC unit outputs power to the load; wherein, K1 is a real number greater than 0. The power and energy control method of the multi-energy complementary DC micro-grid of the present invention can not only maintain the power and energy balance in the DC micro-grid, but also respond to the demand for peak regulation of the power grid, and further reduce the cost of electricity; at the same time, it can maximize the use of new energy, so that from The total electricity consumed by the grid is greatly reduced, reducing carbon emissions. Therefore, the present invention effectively overcomes various shortcomings in the prior art and has high industrial application value.

The above-mentioned embodiments only illustrate the principles and effects of the present invention, but are not intended to limit the present invention. Anyone skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical ideas disclosed in the present invention should still be covered by the claims of the present invention.

Claims (11)

1. A power energy control method of a multi-energy complementary DC micro-grid, the multi-energy complementary DC micro-grid includes an AC-to-DC unit and at least one new energy generating device, an energy storage battery, and a bidirectional DC-to-DC unit, characterized in that , the multi-energy complementary DC microgrid power energy control method at least includes: During the trough period of electricity consumption, when the daily average power generated by the new energy is greater than K1 times the average daily power consumption of the load, the bidirectional DC-to-DC unit outputs power to the load; when the daily average power generated by the new energy is less than K1 times When the load consumes average daily power, the bidirectional DC-to-DC unit charges the energy storage battery; During the undulating period of power consumption, the bidirectional DC-to-DC unit outputs power to the load; During the peak period of power consumption, the bidirectional DC-to-DC unit outputs power to the load; Wherein, K1 is a real number greater than 0. 2. The power energy control method of multi-energy complementary DC microgrid according to claim 1, characterized in that: the method for judging the relationship between the daily average power generation of the new energy source and the daily average power consumption of the load of K1 times comprises: If the cumulative power generation of the new energy on the day is greater than K1 times the cumulative power consumption of the load on the day, it is judged that the daily average power generated by the new energy is greater than the average daily power consumption of the load by K1 times; otherwise, it is judged that the daily average power generated by the new energy is less than K1 times the daily average power consumption of the load. 3. The power energy control method of multi-energy complementary DC microgrid according to claim 1, characterized in that: the method for judging the relationship between the daily average power generation power of the new energy source and the daily average power consumption of the load of K1 times comprises: During peak hours and flat periods of electricity consumption, when the real-time power generated by the new energy is greater than K2 times the real-time power consumption of the load, the timer will be self-increased; If the timing result of the timer is greater than or equal to the preset time, it is judged that the daily average power generation of the new energy is greater than K1 times the average daily power consumption of the load; otherwise, it is judged that the daily average power generation of the new energy is less than K1 times the load Daily average power consumption; Wherein, K2 is a real number greater than 0. 4. The power energy control method of the multi-energy complementary DC microgrid according to any one of claims 1-3, characterized in that: during the valley period of electricity consumption: When the daily average power generated by the new energy is greater than K1 times the average daily power consumption of the load, if the remaining power of the energy storage battery is greater than the first set power, the bidirectional DC-to-DC unit outputs power to the load , and the output power of the bidirectional DC-to-DC unit is the preset output power of the energy storage battery; When the daily average power generated by the new energy source is less than K1 times the daily average power consumption of the load, and if the remaining power of the energy storage battery is less than the upper limit of power, the bidirectional DC-to-DC unit charges the energy storage battery. 5. The power energy control method of the multi-energy complementary DC micro-grid according to any one of claims 1-3, characterized in that: during the wave-level period of power consumption: When the new energy real-time power generation power is less than or equal to K2 times the load real-time power consumption, and the new energy daily average power generation power is greater than K1 times the load daily average power consumption, the output power of the bidirectional DC-to-DC unit is a preset value ; When the real-time power generated by the new energy is less than or equal to K2 times the real-time power consumption of the load, and the daily average power generated by the new energy is less than the daily average power consumption of the load K1 times, the output power of the bidirectional DC-to-DC unit is based on the Describe the real-time power generation changes of new energy sources; When the real-time power generated by the new energy source is greater than K2 times the real-time power consumption of the load, the output power of the bidirectional DC-to-DC unit changes according to the real-time power consumption of the load; Wherein, K2 is a real number greater than 0. 6. The power energy control method of the multi-energy complementary DC micro-grid according to claim 5, characterized in that: in the wave-level period of electricity consumption: When the real-time power generated by the new energy is less than or equal to K2 times the real-time power consumption of the load, and the daily average power generated by the new energy is greater than the daily average power consumption of the load K1 times, the energy storage battery passes the bidirectional DC to DC The unit outputs power to the load; at this time, if the real-time power consumption of the load is greater than the preset output power of the energy storage battery, the output power of the bidirectional DC-to-DC unit is the preset output power of the energy storage battery ; If the real-time power consumption of the load is less than or equal to the preset output power of the energy storage battery, the output power of the bidirectional DC-to-DC unit is zero or alternate output power; When the real-time power generated by the new energy is less than or equal to K2 times the real-time power consumption of the load, and the daily average power generated by the new energy is less than the daily average power consumption of the load K1 times, the new energy power generation device passes the two-way DC converter The DC unit outputs power to the load, and the output power of the bidirectional DC-to-DC unit is K3 times the new energy real-time power generation power; When the real-time power generated by the new energy source is greater than K2 times the real-time power consumption of the load, the bidirectional DC-to-DC unit outputs power to the load, and the output power of the bidirectional DC-to-DC unit is K4 times the real-time power consumption of the load; Wherein, both K3 and K4 are real numbers greater than 0. 7. The power energy control method of multi-energy complementary DC micro-grid according to claim 6, characterized in that: when the real-time power generated by the new energy is less than or equal to K2 times the load real-time power consumption, and the daily average power generated by the new energy When the daily average power consumption of the load is greater than K1 times, if the remaining power of the energy storage battery is greater than the second set power, the energy storage battery outputs power to the load through the bidirectional DC-to-DC unit; If the remaining power of the battery is less than or equal to the second set power, the output power of the bidirectional DC-to-DC unit is zero. 8. The power energy control method of multi-energy complementary DC microgrid according to claim 1, characterized in that: during the peak period of electricity consumption: When the new energy real-time power generation is greater than the preset power generation, if the real-time power consumption of the load is greater than the rated output power of the bidirectional DC-to-DC unit, the output power of the bidirectional DC-to-DC unit is the preset output of the energy storage battery The sum of the power and the real-time power generated by the new energy; if the real-time power consumption of the load is less than the minimum output power of the bidirectional DC-to-DC unit, the output power of the bidirectional DC-to-DC unit is the minimum output power or the output power is zero ; Otherwise, the output power of the bidirectional DC-to-DC unit is K5 times the real-time power consumption of the load; When the real-time generated power of the new energy is less than or equal to the preset generated power, if the real-time power consumption of the load is greater than the preset output power of the energy storage battery, the output power of the bidirectional DC-to-DC unit is equal to that of the storage battery. The preset output power of the energy storage battery; if the real-time power consumption of the load is less than or equal to the preset output power of the energy storage battery, the output power of the bidirectional DC-to-DC unit is zero or alternate output power; Among them, K5 is a real number. 9. The power energy control method of multi-energy complementary DC microgrid according to claim 8, characterized in that: when the real-time power generated by the new energy is greater than the preset power, or the real-time power generated by the new energy is less than or equal to the preset power power and the real-time power consumption of the load is greater than the preset output power of the energy storage battery, if the remaining power of any energy storage battery is less than the first preset power, the output power of the corresponding bidirectional DC-to-DC unit to zero. 10. The power energy control method of multi-energy complementary DC microgrid according to any one of claims 6-9, characterized in that: the output power of the bidirectional DC-to-DC unit is zero or the alternate output power includes: the The bidirectional DC-to-DC unit is set to N groups, if N=1, the output power of the bidirectional DC-to-DC unit is zero; if N is an integer greater than or equal to 2, then N groups of bidirectional DC-to-DC units alternate time-sharing The load output power, at this time, regularly calculate the remaining power of the energy storage battery corresponding to each bidirectional DC-to-DC unit, and select the output power of M groups of bidirectional DC-to-DC units with a larger remaining power of the energy storage battery, and The output power of each bidirectional DC-to-DC unit is 1/N of the preset output power of the energy storage battery, and M is an integer greater than or equal to 1 and less than N. 11. The power energy control method of the multi-energy complementary DC micro-grid according to any one of claims 1-3, characterized in that: the multi-energy complementary DC micro-grid is also provided with AC power equipment, when the When the daily average power generation of the new energy is less than K1 times the average daily power consumption of the load, and the AC grid is normal, the AC grid supplies power to the AC power equipment; otherwise, the DC bus passes the DC to AC unit to supply the AC power Power supply for electrical equipment.

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