KR20220106543A - System and Method for Improving System Power Quality using BEMS - Google Patents

Abstract

According to the present invention, a system power quality increasing system using a BEMS comprises: a building facility control unit for adjusting an operation of a power facility of a management target building; a power storing storage which is charged with surplus power of a grid or the building and discharges insufficient power of the grid or the building; and a BEMS configured to maintain grid power quality in a manner of responding to a power peak of the building by using the power storing storage, absorbing it into a power load of the building and the power storing storage when a frequency of grid power is high, reducing the power load of the building when the frequency of the grid power is low, and emitting power to the power storing storage.

Description

System and Method for Improving System Power Quality using BEMS

The present invention relates to a system and method for improving system power quality using a BEMS with power storage storage, and in particular, a system for performing system frequency adjustment and building peak load adjustment using a BEMS equipped with supercapacitor storage and a solar generator A system and method for improving power quality.

The power system must keep the grid frequency constant and minimize the imbalance between power supply and demand so that power can be supplied stably. In addition, the power system must properly secure the reserve power required for the power system, and it is necessary to constantly and continuously operate the power system in consideration of the constraints of the power system such as transient stability and voltage stability. Generators connected to these power systems have constraints such as the generator's increase/deceleration speed, minimum start time and stop time.

However, in recent years, the proportion of new and renewable energy sources has been steadily increasing worldwide due to the depletion of fossil fuels and energy shortages. However, variable power sources such as new and renewable energy sources consist of energy sources whose output is determined according to climate and weather, making it difficult to control the output of power sources. causes

The power generation characteristics of variable power sources are different from those of conventional generators, causing a reduction in system inertia energy and response resources. Since this variable power source is not synchronized with the power system and lowers the inertia of the system when it is input to the system by replacing the existing power source, the frequency change due to the power supply and demand imbalance in the system is larger.

Due to the characteristics of the power system, the problem caused by the output variability of the volatile power source will appear larger. Therefore, measures for the stability of power supply and demand in the power system are urgently needed. Recently, EMS (Energy Management System) and ESS There are attempts to give.

Here, some terms are summarized as follows. FR stands for Frequency Regulation, and is used in contrast to LL (Load Levelizing). Both LL and FR use batteries, but LL is a concept to reduce peak load (in summer) by using excess power during the day. FR is the concept of discharging at low load and charging at high load during system operation. The same charge/discharge or FR is a nationwide frequency adjustment concept, and LL is a concept that controls the maximum load in units of buildings.

In both cases, batteries were supplied and KEPCO has been ambitiously promoted for the past 10 years, but the FR battery business has also been shut down due to a fire, and it is experiencing difficulties in controlling the frequency due to the increase in solar power generation. It is a problem in the case of low state and frequency of

First, when the frequency is low, as shown in FIG. 2 , the large generator is dropped and the solar (500,000 kW) power generation is automatically stopped. As such, if there is an initial large-scale generator shutdown and successive large-scale solar inverters automatically stop, the low frequency is weighted, the UFR (Under Frequency Relay) operates, and a cyclic blackout to prevent system collapse may occur.

Even when the frequency is high, KEPCO orders a solar power operation stop and is seeking a monetary compensation for the amount of SMP (power generation cost) that fails to operate. The reason KEPCO is pushing for the introduction of the system is because there is a concern about an oversupply of electricity as the number of renewable energy power generation facilities such as solar and wind power has increased significantly. Unlike thermal power and nuclear power, which can lower the output by more than 30%, solar power generation cannot easily reduce the amount of power generation. Due to this, if the supply exceeds the demand for electricity, the electrical frequency deviates from the standard (60+02Hz), causing a “quality” problem and, in the worst case, a blackout.

In the case of the above-described LL and FR, the most technologically easy way to stabilize the grid power is to build a large-capacity ESS having sufficient power storage capacity to absorb excess power from the grid and supply insufficient power. As power storage devices that can be used to build such a large-capacity ESS, there are supercapacitors and lithium-ion batteries.

However, since the cost per unit capacity of the supercapacitor is high, it is extremely difficult from an economic point of view to secure sufficient capacity to perform frequency compensation, etc. for the system.

In the case of lithium-ion batteries, due to the limited number of charge/discharge and the risk of fire due to the deteriorated battery due to excessive repeated use, it was insufficiently applied to perform frequency compensation and the like for the system.

Republic of Korea Registration No. 10-1412742

An object of the present invention is to provide a method and system for improving grid power quality using BEMS, which can effectively perform grid frequency adjustment and building peak load adjustment at a low cost.

System power quality improvement system using BEMS according to an aspect of the present invention, a building equipment control unit for controlling the operation of the power equipment of the building to be managed; Power storage storage for charging the system or the remaining power of the building, and discharging the power insufficient in the system or the building; and using the power storage storage to respond to the power peak of the building, and when the frequency of the grid power is high, it is absorbed into the power load of the building and the power storage storage, and when the frequency of the grid power is low, the power load of the building and a BEMS that maintains grid power quality in such a way as to reduce power consumption and dissipate power from the power storage storage.

Here, the BEMS, when the frequency of the grid power becomes higher than a predetermined upper limit criterion, firstly stores the remaining power in the power storage storage, and secondarily increases one or more of the building heating/cooling load and lighting load. .

Here, the BEMS, when the frequency of the grid power is lower than a predetermined upper limit standard, firstly discharging power to the power storage storage to the grid, and secondarily reducing one or more of the building heating/cooling load and lighting load. have.

Here, further comprising a renewable generator for generating electric power from solar energy or wind energy,

The BEMS may respond to a power peak of the building by using the renewable generator and the power storage and maintain system power quality.

Here, the BEMS, when the frequency of the grid power becomes higher than a predetermined upper limit standard, by charging the power storage storage with the generated power of the renewable generator, and increasing one or more of the heating and cooling load and the lighting load of the building, Power of the power storage storage may be consumed.

Here, the BEMS, when the frequency of the grid power is lower than a predetermined upper limit standard, supplies the generated power of the renewable generator and the power discharged from the power storage storage to the grid, and at least one of a building heating/cooling load and a lighting load can reduce

Here, the BEMS includes: a bidirectional DC/AC converter for mutually converting AC power of a grid or building power supply line and DC power of a DC link end; a bidirectional DC/DC converter for mutually converting the DC power of the DC link end and the DC power of the power storage storage; a one-way DC/DC converter converting the DC power of the renewable generator and supplying it to the DC link terminal; a grid switching circuit for switching an output line of the bidirectional DC/AC converter to a grid line; and a building line switching circuit for switching an output line of the bidirectional DC/AC converter to the building power supply line.

Here, the power storage storage may be a supercapacitor storage.

A system power quality improvement method using BEMS according to another aspect of the present invention is a system power quality improvement method performed by a BEMS that manages power energy of a building having a power storage storage and a renewable generator,

monitoring a frequency state of a system for supplying power to the building; if the frequency state is normal, performing power adjustment to the peak load for the building with the renewable generator and the power storage storage; if the frequency state is higher than a predetermined upper limit, performing an adjustment to lower the frequency of the system with the power load of the building and the power storage storage; and when the frequency state is lower than a predetermined lower limit, performing adjustment to increase the frequency of the system with the power load of the building and the power storage storage.

Here, in the step of adjusting the power to the peak load for the building, in order to reduce the energy cost of the building, the power storage storage is charged with the power produced by the renewable generator or grid power at a time when the selling price is low, It is supplied to the power load of the building, and when a peak load occurs in the building, power may be supplied to the building from the renewable generator and the power storage storage.

Here, the step of performing the adjustment to lower the frequency of the system, the step of primarily charging the power storage storage with the power produced by the renewable generator; and if the high state continues as a result of checking the system frequency again, secondarily increasing one or more of the heating/cooling load and the lighting load of the building.

Here, the step of performing the adjustment to increase the frequency of the system, primarily supplying the generated power of the renewable generator and the discharge power of the power storage storage to the system; and if the low state continues as a result of checking the system frequency again, secondarily reducing one or more of the heating/cooling load and the lighting load of the building.

Here, the power storage storage may be a supercapacitor storage, and the renewable generator may be a solar power generator.

If the system power quality improvement method and / or system using the BEMS according to the spirit of the present invention of the above-described configuration is implemented, there is an advantage in that it is possible to suppress the deterioration of power quality due to variability in a system with many renewable energy sources.

The system power quality improvement method and/or system using the BEMS of the present invention has an advantage in that it is possible to increase the response speed of the system power load adjustment and/or frequency adjustment at a low cost.

The method and/or system for improving system power quality using the BEMS of the present invention has an advantage that the frequency response is fast and there is no fire risk.

The system power quality improvement method and / or system using the BEMS of the present invention can prevent the deterioration of the power system frequency quality due to the rapid increase of new and renewable power generation, especially the sunlight, and the power system collapse due to the increase in sunlight, or wide area There is an advantage in that serious side effects such as power failure can be prevented by BEMS-Supercap-FR (frequency control) operation.

1A and 1B are a block diagram and a circuit diagram showing an overview of K-BEMS (consisting of a battery, solar light, lighting equipment, air conditioning equipment, and EMS computer for control).
2 is a comparative table comparing the characteristics of a lithium-ion battery and a supercapacitor.
3A is a block diagram illustrating an embodiment of a system for improving system power quality using a BEMS according to the spirit of the present invention.
Fig. 3B is a circuit diagram showing internal functional blocks of the BEMS of Fig. 3A;
4A is a block diagram illustrating an operation of a system power quality improvement system using the BEMS of FIG. 2A for mitigating the system frequency in a high state.
FIG. 4B is a block diagram illustrating the operation of the system power quality improvement system using the BEMS of FIG. 2A for mitigating the system frequency in a low state.
Figure 5a is a block diagram showing the operation of the grid power quality improvement system using the BEMS of Figure 2a when the load of the building is high in a state where the frequency of the grid is normal.
Figure 5b is a block diagram showing the operation of the system power quality improvement system using the BEMS of Figure 2a when the load of the building is low in a state where the frequency of the system is normal.
Figure 5c is a block diagram showing the operation of the system power quality improvement system using the BEMS of Figure 2a when the load of the building is low and there is no photovoltaic power in a state where the frequency of the system is normal.
6 is a flowchart illustrating an embodiment of a system power quality improvement method using a BEMS according to the spirit of the present invention.

In describing the present invention, terms such as first, second, etc. may be used to describe various components, but the components may not be limited by the terms. The terms are only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, a first component may be referred to as a second component, and similarly, a second component may also be referred to as a first component.

When a component is referred to as being connected or connected to another component, it may be directly connected or connected to the other component, but it can be understood that other components may exist in between. .

The terms used herein are used only to describe specific embodiments, and are not intended to limit the present invention. The singular expression may include the plural expression unless the context clearly dictates otherwise.

In this specification, the terms include or include are intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, and includes one or more other features or numbers, It may be understood that the possibility of the presence or addition of steps, operations, components, parts, or combinations thereof is not precluded in advance.

In addition, shapes and sizes of elements in the drawings may be exaggerated for clearer description.

1A and 1B are a block diagram and a circuit diagram showing an overview of K-BEMS (consisting of a battery, solar light, lighting equipment, air conditioning equipment, and an EMS computer for control).

The illustrated K-BEMS (KEPCO Building Energy Management System) was developed by KEPCO and was distributed to over 120 KEPCO office buildings nationwide to pursue a connected power supply system for buildings in operation. Although the initial expansion was vigorously pursued with great anticipation, several problems were raised, such as a battery fire and a case of deterioration of power frequency due to solar power, which made it difficult to expand and disseminate nationwide.

In the present invention, in the case of LL and FR, as a method for effectively suppressing power quality degradation due to variability in the system, a system frequency and peak power adjustment method using a BEMS (Building Energy Management System) and supercapacitor storage is proposed. . At the current level of technology, the combination of BEMS and supercapacitor storage is optimal, but if the quality of secondary batteries is improved in the future in terms of stability and charge/discharge recovery, a combination of BEMS and secondary battery power storage is also possible, which is also the present invention It is, of course, within the scope of the

First, at the current level of technology, the advantages of applying the BEMS (Building Energy Management System) and supercapacitor storage will be described.

2 is a comparison of the characteristics of a lithium ion battery and a supercapacitor (abbreviated as a supercap).

In Figure 2, the battery performs the same function as the supercap, but is quite a contrast in function.

The energy density of the battery is much higher, but the power density of the supercap is far superior. This means quick response, and the supercap is much more advantageous for FR. Moreover, batteries have a fire hazard at high currents, and the occurrence of dendrite formation due to aging and battery fires due to this is gradually increasing. Supercap is “Electro Static”, so there is no fire risk, and it is suitable for FR because it has excellent quick response (power load tracking, FR, frequency regulation).

On the other hand, the battery is not suitable for FR because the risk of fire increases when FR is performed (because it has to generate a larger current that responds to FR at the same time). In other words, the supercap has a large power density, so it can generate instantaneous power much better and is safe from fire, so it is suitable for FR, but the battery does not and FR increases the risk.

The aforementioned K-BEMS was developed with Load Leveling (LL) operation and is being used to reduce building energy and reduce peak load, but battery operation is in a state of suspension due to a fire problem. In addition, a megawatt-class (MW) FR battery, which is much larger than K-BEMS, was installed in the amount of 10 containers at the substation site and operated FR.

However, if the battery operating in conjunction with the K-BEMS is replaced with a supercap, the above-described fire problem can be prevented. This means that the supercap only carries electrons and does not involve the movement of ions - the battery is “Mass Transfer” and the supercap is “Energy Transfer”. - The function is the same, but the driving algorithm is different, and the explosive response increases as the battery temperature increases, but the supercap has no such characteristic and there is no fire risk.

In addition, the supercap has a better charge/discharge life than a battery, and the cost is also low as shown in the lower part of FIG. Specifically, a lithium-ion battery has a lifespan of 2,000 to 3,000 cycles, but a supercap has a lifespan of more than one million cycles, that is, almost infinite charge/discharge. Nevertheless, the use of batteries has the disadvantage that the supercap occupies a lot of space (about 10 times), so technology development has been focused on batteries with high energy density, giving priority to batteries, but due to the recent battery fire Supercaps are rapidly emerging as an alternative material.

Only electric vehicle use may be limited by the volume problem, but for power load management or power frequency management, it is enough to replace the battery without any restrictions because the site area needs to be slightly increased. In this sense, especially in terms of fire safety, it is significantly superior. That is, battery fire is a problem, and by replacing the battery with a supercap, it is possible to prevent a fire.

In addition, since the supercap is excellent in terms of frequency regulation (FR), if the K-BEMS system and the supercap are linked, the FR function for the system can be added. This is because the supercap has much better quick response than the battery. The quick response means power density, and the power density is 10 times or more superior to that of a battery. In summary, the supercap is far superior to the battery in the FR (Frequency Regulation) operation mode that needs to quickly supply power to load fluctuations.

However, since the cost per unit storage capacity of the supercap is very high, to cover the FR operation of the system with only the supercap, the cost becomes quite high, and the practicality is lowered. In the case of a hybrid storage device in which a supercap and a lithium-ion battery are combined, the above-described fire risk exists as it is, so it is not suitable for FR use.

In the present invention, in the FR operation of the system, the disadvantage of supercapacitor storage that does not have sufficient capacity due to economic problems is overcome by suggesting a method for auxiliary use of the power load of the building in charge of the BEMS.

From the BEMS point of view, in addition to the general BEMS function, it performs a power frequency quality control function using a photovoltaic generator and supercapacitor storage, and as a means used by the BEMS according to the spirit of the present invention for system frequency control, power current control bidirectional A switch (first tool) and a building power load adjustment means (second tool) may be used.

3A is a block diagram illustrating an embodiment of a system for improving system power quality using a BEMS according to the spirit of the present invention, and FIG. 2B is a circuit diagram illustrating internal functional blocks of the BEMS of FIG. 2A.

The system power quality improvement system using the BEMS shown in FIG. 3A includes: a building facility control unit 200 for controlling the operation of power facilities of a building to be managed; Power storage storage for charging the system or the remaining power of the building, and discharging the power insufficient in the system or the building; and using the power storage storage to respond to the power peak of the building, and when the frequency of the grid power is high, it is absorbed into the power load of the building and the power storage storage, and when the frequency of the grid power is low, the power load of the building and a BEMS 100 for maintaining grid power quality in such a way as to reduce and discharge power from the power storage storage.

As described above, the power storage storage is advantageously the supercapacitor storage 300 at the current technology level.

The BEMS 100 may use the supercapacitor storage 300 and the building equipment control unit 200 as power storage storage in a frequency regulation (FR) operation mode according to the spirit of the present invention.

Specifically, the BEMS 100 stores power remaining in the supercapacitor storage 300 primarily when the frequency of the grid power becomes higher than a predetermined upper limit standard, and secondarily one of a building heating/cooling load and a lighting load. It is possible to instruct the building equipment control unit 200 to increase the abnormality.

Similarly, when the frequency of system power is lower than the predetermined upper limit, the power of the supercapacitor storage 300 is primarily discharged to the system, and secondarily, at least one of the building heating/cooling load and the lighting load is reduced. It may instruct the building equipment control unit 200 .

The BEMS 100 of another implementation in the FR (Frequency Regulation) operation mode according to the spirit of the present invention, the supercapacitor storage 300, the building equipment control unit 200 and the solar power generator 400 as a renewable generator Available. That is, in this case, the system power quality improvement system using the BEMS further includes a renewable generator for generating power using solar energy or wind energy, and the BEMS 100 is the solar generator 400 as the renewable generator. ) and using the supercapacitor storage 300 as the power storage storage to respond to the power peak of the building and maintain the system power quality.

Specifically, the BEMS 100 charges the supercapacitor storage 300 with the generated power of the photovoltaic generator 400 when the frequency of the grid power becomes higher than a predetermined upper limit standard, and the heating and cooling load of the building and By increasing one or more of the lighting loads, the building equipment control unit 200 may be instructed to consume the power of the power storage storage.

Similarly, when the frequency of system power is lower than the predetermined upper limit, the power produced by the solar generator 400 and the power discharged from the supercapacitor storage 300 are supplied to the system, and secondarily, the building heating/cooling load and The building equipment control unit 200 may be instructed to reduce one or more of the lighting loads.

As shown in FIG. 3B, the BEMS 100 includes: a bidirectional DC/AC converter 120 for mutually converting AC power of a grid or building power supply line and DC power of a DC link end; a bidirectional DC/DC converter 140 for mutually converting the DC power of the DC link end and the DC power of the supercapacitor storage 300 as the power storage storage; One-way DC/DC converter 160 for converting the DC power of the photovoltaic generator 400 as the renewable generator and supplying it to the DC link end; a grid switching circuit for switching the output line of the bidirectional DC/AC converter 120 to a grid line; and a building line switching circuit for switching an output line of the bidirectional DC/AC converter 120 to the building power supply line.

Depending on the implementation, the components are additionally isolated from the grid or building power line or a transformer for AC step-up/step-down, a filter for filtering harmonics or noise signals, and protection to protect the internal circuitry of the BEMS 100 from external surges. It may further include a circuit and the like.

Next, a frequency regulation (FR) operation mode and a load levelizing (LL) operation mode performed by the BEMS 100 according to the spirit of the present invention will be described.

4A is a block diagram illustrating the operation of the system power quality improvement system using the BEMS of FIG. 3A for mitigating this in a state where the system frequency is high, and FIG. 4B is a diagram of FIG. It is a block diagram showing the operation of the system power quality improvement system using BEMS.

As shown in FIG. 4a , in the case of FR high operation, the BEMS 100 performs a high-frequency response operation using the supercapacitor storage 300 and the photovoltaic generator 400 . At this time, the BEMS 100 first charges the generated power of the photovoltaic generator 400 in the supercapacitor storage 300 , and increases the power load of the building to the maximum within the prescribed regulations.

The power load increased in the FR high operation may be the heating/cooling load or lighting load of the building, and so that the occupant of the building does not feel discomfort, the person increases the heating/cooling or lighting change at an unrecognizable rate, and Increase within the specified range.

As shown in FIG. 4b , in the case of FR low operation, the BEMS 100 performs low-frequency operation using the supercapacitor storage 300 and the photovoltaic generator 400 . At this time, the BEMS 100 simultaneously discharges the solar generator 400 power and the supercapacitor storage 300 charging power to the system. At the same time, the building load is reduced to a minimum within the prescribed regulations.

The power load that is reduced in the FR low operation may be the heating/cooling load or lighting load of the building, so that the occupant of the building does not feel discomfort, the person increases the heating/cooling or lighting change at an unrecognizable rate, and Increase within the specified range. Depending on the implementation, buildings may only provide emergency power when FR low operation is more urgent than occupant comfort.

Figure 5a is a block diagram showing the operation of the grid power quality improvement system using the BEMS of Figure 3a when the load of the building is high in the state where the frequency of the grid is normal, Figure 5b is the load of the building in the state where the frequency of the grid is normal It is a block diagram showing the operation of the system power quality improvement system using the BEMS of FIG. 3A.

Meanwhile, FIG. 5C is a block diagram illustrating the operation of the system power quality improvement system using the BEMS of FIG. 3A when the load of the building is low and there is no solar power generation in a state where the frequency of the system is normal.

As shown in FIG. 5A, when the power load of the target building is high as the LL operation in the normal frequency state, the supercapacitor storage 300 and the photovoltaic generator 400 reduce the building load, that is, temporarily reduce the peak load. drive for The operation for the temporary peak load reduction is a basic function provided when the K-BEMS is first presented, and the supercapacitor storage 300 and the photovoltaic generator 400 are simultaneously installed under the building maximum load, that is, the contract power conservation dimension. to perform maximum discharge/transmission.

When the power load of the target building is low as the LL operation in the normal frequency state, when the power generated by the photovoltaic generator 400 is present, as shown in FIG. 5B , the supercapacitor storage 300 is first charged.

On the other hand, when the power load of the target building is low as the LL operation in the normal frequency state, there is no power generated by the photovoltaic generator 400 due to weather or the like, or when a renewable generator is not provided, As shown, the supercapacitor storage 300 is charged with system power.

The operation diagrams shown in FIGS. 5B and 5C described above are basic functions provided when the K-BEMS is first presented.

6 is a flowchart illustrating an embodiment of a method for improving system power quality using a BEMS according to the spirit of the present invention.

The system power quality improvement method performed by the BEMS for managing the power energy of a building having a power storage storage and a renewable generator according to the flowchart shown is the step of monitoring the frequency state of the system supplying power to the building (S100) ); If the frequency state is normal, performing power adjustment to the peak load for the building with the renewable generator and the power storage storage (S200); If the frequency state is higher than a predetermined upper limit, performing an adjustment to lower the frequency of the system to the power load of the building and the power storage storage (S400); and when the frequency state is lower than a predetermined lower limit, performing adjustment to increase the frequency of the system with the power load of the building and the power storage storage (S600).

The step (S100) of monitoring the frequency state of the system is by directly reading the KPX frequency value from the EMS of the BEMS (K-BEMS) or indirectly reading the KPX frequency real-time value linked to the KEPCO website. It can be done in the following way. This can be easily implemented through an already published API (Application Programming Interface), and detailed description will be omitted.

As a result of checking the frequency state of the system ( S101 ), if the system frequency is in the normal frequency range, step S200 is performed.

In the step (S200) of performing power adjustment to the peak load for the building, in order to reduce the energy cost of the building, the power storage storage is charged with the power produced by the renewable generator or grid power at a time when the selling price is low. , but supplied to the power load of the building, when a peak load occurs in the building, power may be supplied to the building from the renewable generator and the power storage storage.

Specifically, if the case of step S200 is exemplified, when the system frequency is in the normal range as the normal frequency (within 60±02 Hz), the load leveling operation, that is, for reducing the building peak load and maximal energy saving, supercapacitor The existing K-BEMS function of supplying the power load of the building with the power of the storage 300 and the photovoltaic generator 400 is performed. By the way, although mentioned as the existing K-BEMS function, the LL mode operation of the existing K-BEMS is, regardless of the grid frequency, the power of the supercapacitor storage 300 and the photovoltaic generator 400 to reduce building energy and It should be noted that there is a difference in use for maximum peak load reduction.

As a result of checking the frequency state of the system (S101), if the system frequency is in the high-frequency region, step S400 is performed.

In the step (S400) of performing the adjustment to lower the frequency of the system, the power storage storage is charged with the generated power of the renewable generator, and by increasing one or more of the heating and cooling load and the lighting load of the building, the power is stored Consumes storage power.

Specifically, performing the adjustment to lower the frequency of the system (S400) is, as shown, primarily charging the supercapacitor storage 300 with the generated power of the photovoltaic generator 400 ( S420); If the high state is maintained as a result of checking the system frequency again (S440) despite the execution of step S420, the high-frequency BEMS operation (FR) is performed to increase at least one of the heating/cooling load and the lighting load of the building to consume the remaining power. It may include a step (S460) of doing.

If the step S400 is illustrated as a specific numerical value, in the process of checking the frequency quality requirements (60±02) in the BEMS, if the system frequency state is determined to be high frequency, that is, if the power system frequency is greater than 60.2 Hz ( If frequency is more than 60.2 Hz), the photovoltaic generator 400 power is stored in the supercapacitor storage 300 without discharging it to the grid. Through this, an additional increase in the system frequency or a decrease in the system frequency can be achieved. Nevertheless, if the frequency is still not lowered, the BEMS system immediately begins to increase the building load and thereby pushes the frequency reduction. Specifically, it is possible to increase the load on the building and lower the system frequency by controlling the heating and cooling temperature, dimming control, and the like. As described above, if the frequency control proposed in the spirit of the present invention is further explained, the supercapacitor storage 300 and the solar generator 400 are used as the first tool for power consumption, and the BEMS power load control (cooling and heating load control, It means that frequency control is performed using lighting control, etc.) as a second tool.

As a result of checking the frequency state of the system (S101), if the system frequency is in the high-frequency region, step S600 is performed.

In the step (S600) of performing the adjustment to increase the frequency of the system, the power produced by the renewable generator and the power discharged from the power storage storage are supplied to the system, and at least one of a building heating/cooling load and a lighting load is reduced can do it

Specifically, performing the adjustment to increase the frequency of the system (S600), as shown, primarily the production power of the photovoltaic generator 400 and the discharge power of the supercapacitor storage 300 supplying to the system (S620); If the low state is maintained as a result of checking the system frequency again (S440) despite the execution of step S620, performing a low-frequency BEMS operation (FR) for reducing at least one of the heating/cooling load and the lighting load of the building (S660) may include.

If the S600 step is exemplified as a specific numerical value, in the process of checking the frequency quality requirements (60±02) in the BEMS, if the system frequency state is determined to be a low frequency (If frequency is less than 598 Hz), the solar generator 400 and supercapacitor storage 300 are discharged to the system at the same time to add power to return the system frequency to normal. If the frequency control is not normal even with this, the building heating/cooling load and lighting control are similarly mobilized. In other words, it cuts off the building's heating/cooling load and dims the building's lighting load to reduce all loads except for emergency power sources such as elevators as much as possible to raise the system frequency and return the frequency to normal 60Hz. In this way, if the frequency control proposed in the spirit of the present invention is further explained, the supercapacitor storage 300 and the solar generator 400 are used as the first tools, and the BEMS power load control (cooling/heating load control, lighting control, etc.) ) as a second tool to perform frequency control.

The system power quality improvement method using the BEMS according to the spirit of the present invention described above uses the BEMS for system adjustment having a supercapacitor, and when the frequency is high, the power is primarily stored in the supercapacitor, and the supercapacitor is frequently used in a day. is used for charging/discharging, but it is possible to prepare for frequency adjustment using the building load during the time the supercapacitor operates primarily.

The above description is merely illustrative of the technical spirit of the present invention, and various modifications and variations will be possible without departing from the essential characteristics of the present invention by those skilled in the art to which the present invention pertains. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention, but to illustrate, and the scope of the technical spirit of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

100: BEMS
120: bidirectional DC/AC converter
140: bidirectional DC/DC converter
160: unidirectional DC/DC converter
200: building equipment control unit
300: supercapacitor storage
400: solar generator

Claims (13)

A building equipment control unit for controlling the operation of the power equipment of the building to be managed;
Power storage storage for charging the system or the remaining power of the building, and discharging the power insufficient in the system or the building; and
Corresponding to the power peak of the building using the power storage storage, if the frequency of the grid power is high, it is absorbed into the power load of the building and the power storage storage, and if the frequency of the grid power is low, the power load of the building is reduced BEMS to maintain grid power quality by reducing and dissipating power from the power storage storage.
System power quality improvement system using BEMS comprising a.
The method of claim 1
The BEMS is,
When the frequency of the grid power becomes higher than the predetermined upper limit standard,
Storing the remaining power in the power storage storage primarily,
A grid power quality improvement system that secondaryly increases one or more of the building's heating and cooling loads and lighting loads.
The method of claim 1
The BEMS is,
When the frequency of the grid power is lower than the predetermined upper limit,
First discharging power to the power storage storage system,
A grid power quality improvement system that secondaryly reduces one or more of the building's heating and cooling loads and lighting loads.
According to claim 1,
Renewable generators that generate electricity from solar or wind energy
further comprising,
The BEMS is,
A grid power quality improvement system for responding to the power peak of the building and maintaining the grid power quality by using the renewable generator and the power storage storage.
5. The method of claim 4
The BEMS is,
When the frequency of the grid power becomes higher than the predetermined upper limit standard,
charging the power storage storage with the power produced by the renewable generator,
The system power quality improvement system for consuming power of the power storage storage by increasing at least one of a heating/cooling load and a lighting load of the building.
5. The method of claim 4
The BEMS is,
When the frequency of the grid power is lower than the predetermined upper limit,
Supplying the generated power of the renewable generator and the power discharged from the power storage storage to the system,
A grid power quality improvement system that reduces one or more of the building's heating and cooling loads and lighting loads.
5. The method of claim 4,
The BEMS is,
a bidirectional DC/AC converter for mutually converting AC power from a grid or building power supply line and DC power from a DC link end;
a bidirectional DC/DC converter for mutually converting the DC power of the DC link end and the DC power of the power storage storage;
a one-way DC/DC converter converting the DC power of the renewable generator and supplying it to the DC link terminal;
a grid switching circuit for switching an output line of the bidirectional DC/AC converter to a grid line; and
A building line switching circuit for switching the output line of the bidirectional DC/AC converter to the building power supply line
Grid power quality improvement system comprising a.
According to claim 1,
The system power quality improvement system, characterized in that the power storage storage is a supercapacitor storage.
As a system power quality improvement method performed by BEMS that manages power energy of a building equipped with power storage storage and a renewable generator,
monitoring a frequency state of a system for supplying power to the building;
if the frequency state is normal, performing power adjustment to the peak load for the building with the renewable generator and the power storage storage;
if the frequency state is higher than a predetermined upper limit, performing an adjustment to lower the frequency of the system with the power load of the building and the power storage storage; and
If the frequency state is lower than a predetermined lower limit, performing an adjustment to increase the frequency of the system with the power load of the building and the power storage storage
A method for improving system power quality, comprising:
10. The method of claim 9,
In the step of performing power adjustment to the peak load for the building,
In order to reduce the energy cost of the building, the power storage storage is charged with the power produced by the renewable generator or grid power at a time when the selling price is low, and supplied to the power load of the building, but when a peak load occurs in the building A system power quality improvement method for supplying power from the renewable generator and the power storage storage to the building.
8. The method of claim 7,
The step of performing the adjustment to lower the frequency of the system,
primarily charging the power storage storage with the power produced by the renewable generator; and
Secondarily increasing one or more of the heating/cooling load and the lighting load of the building if the high state continues as a result of checking the system frequency again
A method for improving system power quality, comprising:
8. The method of claim 7,
The step of performing the adjustment to increase the frequency of the system,
primarily supplying the generated power of the renewable generator and the discharged power of the power storage storage to the system; and
Secondary reducing one or more of the heating/cooling load and the lighting load of the building if the low state continues as a result of checking the system frequency again
A method for improving system power quality, comprising:
10. The method of claim 9,
The power storage storage is a supercapacitor storage,
The renewable generator is a system power quality improvement method, characterized in that the photovoltaic generator.

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