CN213243559U - Energy storage AGC combined power grid frequency modulation system - Google Patents

Abstract

The utility model provides an energy storage AGC combined power grid frequency modulation system, which comprises a power grid dispatching device, a generator set, an energy storage device, a unit distributed control device, an energy storage distributed control device and an output power grid; when the power grid AGC instruction is a power increasing instruction, the power grid AGC instruction comprises a first energy storage device electronic instruction, a first energy storage device charging sub-instruction and a power increasing stabilizing sub-instruction; and when the power grid AGC instruction is a power reduction instruction, the power grid AGC instruction comprises a second energy storage device electronic charging instruction, a second energy storage device electronic placing instruction and a power control reduction stabilizing sub-instruction. The utility model can carry out the overshoot operation to the output power of the generator set through the energy storage device, thereby avoiding the occurrence of power regulation delay, deviation and reversal; meanwhile, the high-rate charge and discharge capacity and the high cycle service life of the carbon-based capacitor battery improve the adjustment precision and the adjustment frequency of the output power of the generator set, and reduce the adjustment cost.

Description

Energy storage AGC combined power grid frequency modulation system

Technical Field

The utility model relates to a power grid frequency modulation field especially relates to a power grid frequency modulation system is united to energy storage AGC.

Background

In the operation of an electric power system, AGC (Automatic Generation Control) mainly adjusts active processing of a frequency modulation power supply in a power grid in real time, so as to Control the power grid frequency and the tie line power, solve the problem of active balance with random characteristics in a regional power grid with a short time scale of second or minute, and provide high requirements for AGC power supply performance, such as high adjustment speed, high adjustment precision, frequent power adjustment direction conversion, and the like.

The AGC frequency modulation function of the existing power grid is mainly provided by conventional power supplies such as hydropower, gas generating units, thermal power generating units and the like, the power supplies are composed of mechanical devices with rotating inertia, and a series of complex processes are carried out when primary energy is converted into electric energy, so that the AGC frequency modulation performance of the power grid is far away from the adjustment expectation of the power grid.

Specifically, as shown in fig. 1, fig. 1 is a schematic diagram of a response process of an existing thermal power generating unit responding to a power grid AGC instruction, where a curve a is a scheduling target power curve of the scheduling AGC instruction, and a curve B is a scheduling actual power curve of the thermal power generating unit. It can be seen that the load response of a general thermal power plant has the problems of regulation delay (such as the B1 region), regulation deviation (such as the B2 region) and regulation reversal (such as the B3 region), which are particularly prominent when a regulation command is issued and the direction is changed.

Therefore, it is necessary to provide an energy storage AGC combined power grid frequency modulation system to solve the problems in the prior art.

SUMMERY OF THE UTILITY MODEL

The embodiment of the utility model provides a can realize quick real-time frequency modulation's of electric wire netting energy storage AGC unites electric wire netting frequency modulation system to there is power regulation delay, power regulation deviation and the reverse technical problem of power regulation easily in solving current electric wire netting frequency modulation system.

The embodiment of the utility model provides an energy storage AGC unites electric wire netting frequency modulation system, it includes:

the power grid dispatching equipment is used for generating a power grid AGC instruction based on the power demand so as to generate the rated power of the generator set;

the generator set is used for generating power to output the output power of the generator set;

the energy storage device is used for storing energy and correcting the output power of the generator set by using the stored energy based on the rated power of the generator set;

the unit distributed control equipment is connected with the power grid dispatching equipment and used for driving the generator unit to perform power generation control operation based on the power grid AGC command;

the energy storage distributed control equipment is connected with the power grid dispatching equipment and used for driving the energy storage device to perform energy storage or energy release operation based on the power grid AGC command; and

the output power grid is respectively connected with the generator set and the energy storage device and used for outputting electric energy corresponding to the power consumption demand based on the corrected output power of the generator set;

the energy storage device comprises a plurality of groups of carbon-based capacitive batteries and corresponding current transformers;

when the power grid AGC instruction is a power boosting instruction, the power grid AGC instruction comprises a first energy storage device discharging sub-instruction for controlling the output power of the generator set to reach the rated power of the generator set, a first energy storage device charging sub-instruction for controlling the output power of the generator set to be higher than the rated power of the generator set, and a power boosting stabilizing sub-instruction for controlling the output power of the generator set to be equal to the rated power of the generator set;

and when the power grid AGC instruction is a power reduction instruction, the power grid AGC instruction comprises a second energy storage device charging sub-instruction for controlling the output power of the generator set to reach the rated power of the generator set, a second energy storage device discharging sub-instruction for controlling the output power of the generator set to be higher than the rated power of the generator set, and a power reduction stabilizing sub-instruction for controlling the output power of the generator set to be equal to the rated power of the generator set.

In the energy storage AGC combined power grid frequency modulation system of the utility model, the generator set has the maximum set power regulation speed;

if the power grid AGC instruction is a power boost instruction, and the power boost speed set by the power grid AGC instruction is greater than the maximum set power regulation speed of the generator set; the grid AGC instruction comprises:

a first energy storage device discharges an electronic command, the generator set is in a generating power lifting state, and the energy storage device releases energy to the output power grid;

a first energy storage device charging sub-instruction, wherein the generator set is in a power generation high-power fluctuation state, and the energy storage device stores energy from the output power grid;

a power increasing stabilizer command, wherein the generator set is in a high-power stable power generation state, and the energy storage device is in a standby state;

if the power grid AGC command is a power reduction command, and the power reduction speed set by the power grid AGC command is greater than the maximum set power regulation speed of the generator set, the power grid AGC command comprises:

a second energy storage device charging sub-instruction, wherein the generator set is in a power generation power reduction state, and the energy storage device stores energy from the output power grid;

a second energy storage device discharges an electronic command, the generator set is in a low-power generation fluctuation state, and the energy storage device releases energy to the output power grid;

and (5) power reduction and stabilization sub-instructions, wherein the generator set is in a low-power stable power generation state, and the energy storage device is in a standby state.

In the energy storage AGC joint grid frequency modulation system of the present invention, the energy released by the energy storage device into the output grid at the first energy storage device discharging sub-command stage of the grid AGC command is less than or equal to the energy stored by the energy storage device from the output grid at the first energy storage device charging sub-command stage of the grid AGC command;

and the energy stored in the output power grid by the energy storage device in the second energy storage device electronic instruction charging stage of the power grid AGC instruction is more than or equal to the energy released into the output power grid by the energy storage device in the second energy storage device electronic instruction setting stage of the power grid AGC instruction.

In the energy storage AGC combined power grid frequency modulation system of the present invention, in the sub-command discharging stage of the first energy storage device, the energy release speed of the energy storage device is determined according to the difference between the power boost speed set by the power grid AGC command and the maximum set power regulation speed of the generator set;

in the first energy storage device charging instruction stage, determining the time of the generator set in a power generation high-power fluctuation state according to the energy release amount of the energy storage device;

in the second energy storage device charging instruction stage, determining the energy storage speed of the energy storage device according to the difference value between the power reduction speed set by the power grid AGC instruction and the maximum set power regulation speed of the generator set;

and in the stage of placing the electronic instruction by the second energy storage device, determining the time of the generator set in the power generation low-power fluctuation state according to the energy storage amount of the energy storage device.

In the energy storage AGC combined power grid frequency modulation system of the present invention, the maximum output power of the generator set in the power generation high power fluctuation state is 104% -106% of the stable output power of the generator set in the corresponding power generation high power stable state;

the lowest output power of the generator set in the power generation low-power fluctuation state is 97% -98% of the stable output power of the generator set in the corresponding power generation low-power stable state.

In the energy storage AGC combined power grid frequency modulation system, the energy storage device is a carbon-based capacitor battery, and the energy storage power of the energy storage device is 2% -3% of the rated power of the generator set.

In the energy storage AGC combined power grid frequency modulation system of the present invention, the initial storage energy of the energy storage device is 45% -65% of the maximum storage energy.

In the energy storage AGC combined power grid frequency modulation system, the energy storage AGC combined power grid frequency modulation system further includes:

the output detection device is respectively connected with the power grid dispatching equipment, the generator set and the energy storage device, and is used for detecting the generator set output energy of the generator set and the battery output energy of the energy storage device and feeding back the generator set output energy and the battery output energy to the power grid dispatching equipment;

and the power grid dispatching equipment is also used for generating a power grid AGC correction instruction for adjusting the unit output energy and the battery output energy according to the unit output energy and the battery output energy.

In the energy storage AGC combined power grid frequency modulation system, the energy storage AGC combined power grid frequency modulation system further includes:

and the electric energy output module is connected with the energy storage device and used for outputting the energy of the energy storage device.

Energy storage AGC unites electric wire netting frequency modulation system in, carbon back electric capacity battery's charge-discharge multiplying power is 10 times to 20 times.

The utility model discloses an energy storage AGC unites electric wire netting frequency modulation system to carry out the overshoot operation to actual electric wire netting power through energy memory to make actual electric wire netting power can reach target electric wire netting power fast, avoided the reverse emergence of power regulation delay, power regulation deviation and power regulation; the technical problems that the power regulation delay, the power regulation deviation and the power regulation reversal easily exist in the conventional power grid frequency modulation system are effectively solved.

Drawings

Fig. 1 is a schematic diagram of a response process of a conventional thermal power generating unit responding to a power grid AGC command;

fig. 2 is a schematic structural diagram of an embodiment of the energy storage AGC combined power grid frequency modulation system of the present invention;

fig. 3 is a schematic diagram of a corresponding process of a power grid AGC command according to an embodiment of the energy storage AGC combined power grid frequency modulation system of the present invention;

FIG. 4 is a schematic flow chart of the power grid frequency modulation using the energy storage AGC combined power grid frequency modulation system of the present invention;

fig. 5 is the power adjustment schematic diagram of the generator set, the energy storage device and the output power grid of the energy storage AGC combined power grid frequency modulation system of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by the skilled in the art without creative work belong to the protection scope of the present invention.

The utility model provides an energy storage AGC unites electric wire netting frequency modulation system please refer to fig. 2, and fig. 2 is the utility model discloses an energy storage AGC unites electric wire netting frequency modulation system's an embodiment's schematic structure. The energy storage AGC combined power grid frequency modulation system can be used for quickly responding to power grid frequency modulation instructions of a power output grid corresponding to the thermal power generating unit in real time, and the problems of power regulation delay, power regulation deviation and reverse power regulation are avoided.

The energy storage AGC combined power grid frequency modulation system comprises power grid scheduling equipment, a generator set, an energy storage device, unit distributed control equipment, energy storage distributed control equipment and an output power grid.

The power grid dispatching equipment is used for generating a power grid AGC instruction based on the power demand so as to generate the rated power of the generator set; the generator set is used for generating electricity to output the output power of the generator set; the energy storage device is used for storing energy and correcting the output power of the generator set by using the stored energy based on the rated power of the generator set; the unit distributed control equipment is connected with the power grid dispatching equipment and used for driving the generator set to perform power generation control operation based on the power grid AGC command; the energy storage distributed control equipment is connected with the power grid dispatching equipment and used for driving the energy storage device to perform energy storage or energy release operation based on the power grid AGC command; and the output power grid is respectively connected with the generator set and the energy storage device and used for outputting electric energy corresponding to the power consumption demand based on the corrected output power of the generator set.

The energy storage device comprises a plurality of groups of carbon-based capacitor batteries and corresponding converters, and the converters can perform rectification operation on the output of each group of carbon-based capacitor batteries.

Specifically, when the power grid AGC instruction is a power boost instruction, the power grid AGC instruction includes a first energy storage device discharge sub-instruction for controlling the output power of the generator set to reach the rated power of the generator set, a first energy storage device charge sub-instruction for controlling the output power of the generator set to be higher than the rated power of the generator set, and a power boost stabilizing sub-instruction for controlling the output power of the generator set to be equal to the rated power of the generator set. The energy storage AGC combined power grid frequency modulation system controls the actual power grid power to be higher than the target power grid power through the first energy storage device charging instruction, and the generator set is subjected to over-frequency adjustment, so that the problems of delay, deviation and the like of power improvement are effectively reduced.

The generator set output power is the actual output power of the power grid controlled and output by the power grid frequency modulation system, and the generator set rated power is the target output power of the power grid AGC command hoped that the power grid frequency modulation system controls and outputs the power grid output.

Specifically, if the power grid AGC command is a power boost command, and the power boost speed set by the power grid AGC command is greater than the maximum set power regulation speed of the generator set, the first energy storage device discharging sub-instruction of the grid AGC instruction is used for controlling the generator set to be in a generating power boosting state, controlling the energy storage device to release energy to an output grid, that is, the generator set and the energy storage device output electric energy to an output power grid at the same time, wherein the energy release speed of the energy storage device can be determined by the difference value between the power boost speed set by the power grid AGC instruction and the maximum set power regulation speed of the generator set, namely the sum of the maximum set power regulation speed of the generator set and the energy release speed of the energy storage device is equal to the power boost speed set by the power grid AGC instruction, therefore, the output electric energy of the output power grid is consistent with the setting of the power grid AGC command in the stage of discharging the sub-command of the first energy storage device.

The first energy storage device charging sub-instruction of the power grid AGC instruction is used for controlling the generator set to be in a power generation high-power fluctuation state, the energy storage device is controlled to store energy from an output power grid, namely the generator set outputs electric energy to the output power grid, and the energy storage device recovers the electric energy from the output power grid. The time of the generator set in the power generation high-power fluctuation state can be determined by the energy release amount of the energy storage device in the first energy storage device charging sub-instruction stage, namely the larger the energy release amount of the energy storage device is, the longer the time of the generator set in the power generation high-power fluctuation state is; the smaller the energy release amount of the energy storage device is, the shorter the time of the generator set in a high-power generation fluctuation state is. The time of the fluctuation state is generally within 20s, so that the communication, sampling and control of other links are not influenced.

Preferably, the generating high-power fluctuation state of the generator set is a fluctuation process of gradually reducing the generator set output power higher than the rated power of the generator set to the rated power of the generator set, and the maximum output power of the generating high-power fluctuation state of the generator set can be 104% -106% of the stable output power of the generating high-power stable state of the generator set, so that the energy storage device can be effectively charged within the specified time.

The power increasing stabilizing sub-instruction of the power grid AGC instruction is used for controlling the generator set to be in a high power generating stable state and controlling the energy storage device to be in a standby state, namely the generator set outputs electric energy with stable power to the output power grid, and the energy storage device returns to the initial standby state.

Since the energy storage device needs to return to the initial standby state to assist the generator set in output power adjustment in the following, the energy released by the energy storage device in the first energy storage device discharging sub-command of the grid AGC command to the output grid should be less than or equal to the energy stored by the energy storage device in the first energy storage device charging sub-command stage of the grid AGC command from the output grid, so as to ensure that the initial energy in the energy storage device remains unchanged (as time goes on, the initial energy in the energy storage device is slowly reduced even if not used for output power adjustment, so the stored energy may be greater than the released energy).

If the power boost speed set by the power grid AGC instruction is less than or equal to the maximum set power regulation speed of the generator set, the power boost instruction can be executed by the power set, so that the output electric energy adjustment corresponding to the power grid AGC instruction can be completed by directly using the generator set, the use frequency of the energy storage device is reduced, and the service life of the energy storage device is prolonged.

If the power grid AGC command is a power reduction command, and the power reduction speed set by the power grid AGC command is greater than the maximum set power regulation speed of the generator set, the second energy storage device charging sub-command of the power grid AGC command is used for controlling the generator set to be in a power generation power reduction state, and controlling the energy storage device to recover energy from an output power grid, namely, the generator set reduces output electric energy, and meanwhile, the energy storage device recovers the output electric energy. The energy storage speed of the energy storage device can be determined by the difference value between the power reduction speed set by the power grid AGC command and the maximum set power regulation speed of the generator set, namely the sum of the maximum set power regulation speed of the generator set and the energy storage speed of the energy storage device is equal to the power reduction speed set by the power grid AGC command, so that the output electric energy of the output power grid is consistent with the setting of the power grid AGC command in the second energy storage device charging command stage.

And a second energy storage device discharging sub-instruction of the power grid AGC instruction is used for controlling the generator set to be in a power generation low-power fluctuation state and controlling the energy storage device to release energy to an output power grid, namely the generator set outputs electric energy to the output power grid, and meanwhile, the energy storage device also outputs the recovered electric energy to the output power grid. The time that the generator set is in the power generation low-power fluctuation state can be determined by the energy storage amount of the storage battery in the second energy storage device charging instruction stage, namely the larger the energy storage amount of the energy storage device is, the longer the generator set is in the power generation low-power fluctuation state; the smaller the energy storage amount of the energy storage device is, the shorter the time of the generator set in the power generation low-power fluctuation state is. The time of the fluctuation state is generally within 20s, so that the communication, sampling and control of other links are not influenced.

Preferably, the generating low-power fluctuation state of the generating set is a fluctuation process of gradually increasing the generating set output power lower than the rated power of the generating set to the rated power of the generating set, and the minimum output power of the generating low-power fluctuation state of the generating set can be 97% -98% of the stable output power of the generating low-power stable state of the generating set so as to effectively discharge the energy storage device within the specified time.

And the power reduction stabilizing sub-instruction of the power grid AGC instruction is used for controlling the generator set to be in a low-power stable power generation state and controlling the energy storage device to be in a standby state, namely the generator set outputs electric energy with stable power to the output power grid, and the energy storage device returns to the initial standby state.

Similarly, the energy stored in the output power grid by the energy storage device in the second energy storage device electronic instruction charging stage of the power grid AGC instruction is more than or equal to the energy released to the output power grid by the energy storage device in the second energy storage device electronic instruction charging stage of the power grid AGC instruction, so that the initial energy in the energy storage device is kept unchanged.

If the power reduction speed set by the power grid AGC instruction is less than or equal to the maximum set power regulation speed of the generator set, the power reduction instruction can be executed by the power generation set, so that the output electric energy adjustment corresponding to the power grid AGC instruction can be completed by directly using the generator set, the use frequency of the energy storage device is reduced, and the service life of the energy storage device is prolonged.

Since the energy storage device needs to perform an energy storage operation or an energy release operation, the energy storage device should set an initial stored energy, which is preferably set to 45% -65% of the maximum stored energy.

The energy storage device of the embodiment preferably uses a carbon-based capacitor battery, and the energy storage power of the energy storage device can be set to be about 2% -3% of the rated power of the generator set. If the generating set is a thermal power generating set with 330MW, the maximum energy storage power of the energy storage device can be set to be 7-10 MW.

The energy storage device of the embodiment has two core advantages by adopting the carbon-based capacitor battery, and firstly, the energy storage device has high-rate charge and discharge capacity and can meet the frequency modulation service of second/minute level; and secondly, the service life of the device is long, and the device can meet the requirements of shallow charging and shallow discharging of a power plant for frequency modulation higher than 300-times/day and 400-times/day.

Meanwhile, from the perspective of cost, the energy storage device adopting the carbon-based capacitor battery can reduce investment cost, operation and maintenance cost and battery cost of the whole life cycle.

The carbon-based capacitor battery supports 10C-20C heavy current charging and discharging, and the charging and discharging multiplying power of other batteries in the market is basically 2C, so that the battery does not have high multiplying power charging and discharging capacity. Therefore, under the condition of charging and discharging rated power, the electric quantity required by the carbon-based capacitor battery is only about 1/2 of the capacity of other types of capacitors, so that the investment cost can be effectively reduced.

In addition, a special battery management system is not required to be arranged on the carbon-based capacitor battery, a heat dissipation system is not required when the current below 3C continuously runs, and the requirement on an air conditioning system is obviously lower than that of other types of batteries, so that the operation and maintenance cost of the energy storage device is lower.

In addition, the cycle service life of the carbon-based capacitor battery is about 20000 times, which is 4-5 times that of other types of batteries, and the battery does not need to be replaced according to the 10-year system service cycle; and the battery with other types needs to be replaced 1-2 times in the frequency modulation environment in the whole life cycle, so that the battery with the whole life cycle of the energy storage device is low in cost.

The carbon-based capacitor battery belongs to a physical battery, so that no pollution and no other generation are caused in the use process; no explosion or fire occurs during short circuit, overcharge, dropping, extrusion, fire, needling and gunshot testing. The temperature of the single battery can not exceed 80 ℃ under the condition of short circuit, and the safety performance is extremely superior. Lithium batteries and lead-carbon batteries belong to the electrochemical class of batteries and both have risks of explosion and fire.

The carbon-based capacitor battery has the characteristics of high-rate charge and discharge, the recovery time after discharge is fast, 80% of electric quantity can be fully charged in about 5 minutes even if the electric quantity is emptied after the battery pack completes the frequency modulation instruction, and the electric quantity can be completely recovered in 20 minutes; while other types of battery capacity recovery time require more than 1 hour. And the carbon-based capacitor battery can properly increase the converter capacity of the energy storage device, and the problem that the comprehensive frequency modulation performance parameters are influenced by the AGC (automatic gain control) instruction of the power grid can be effectively solved by utilizing the short-term peak value multiplying power characteristic of charge and discharge of the carbon-based capacitor battery.

In order to further improve the power grid real-time frequency modulation capability of the energy storage AGC joint power grid frequency modulation system of the embodiment, the energy storage AGC joint power grid frequency modulation system of the embodiment may further include an output detection device and an electric energy output module.

The output detection device is respectively connected with the power grid dispatching equipment, the generator set and the energy storage device, and is used for detecting the generator set output energy of the generator set and the battery output energy of the energy storage device and feeding back the generator set output energy and the battery output energy to the power grid dispatching equipment; therefore, the power grid dispatching equipment can also generate a power grid AGC correction instruction for adjusting the output energy of the unit and the output energy of the battery based on the output energy of the unit and the output energy of the battery.

The generator set is controlled by the generator set distributed control equipment to perform power generation control operation and the energy storage device is controlled by the energy storage distributed control equipment to perform energy storage or energy release operation. At this time, the output detection device directly generates corresponding adjustment feedback, namely a power grid AGC correction instruction, based on the unit output energy and the battery output energy, so as to adjust the current unit output energy and the battery output energy based on the real-time output electric energy of the output power grid.

The power grid AGC correction instruction can directly correct the battery output energy of the energy storage device, so that electric energy corresponding to the output power consumption requirement of the power grid is output.

Since the energy storage device needs to maintain a stored energy of 45% -65% of the maximum stored energy at all times in order to achieve the best frequency modulation effect. In each previous frequency modulation, only the energy loss of the energy storage device is considered, namely, only the energy stored by the energy storage device is ensured to be higher than the energy released by the energy storage device in each frequency modulation stage. Therefore, after a plurality of frequency modulation operations, the stored energy of the energy storage device may be greater than 85% of the maximum stored energy, and may even reach 90% of the maximum stored energy. At this time, the energy storage device cannot perform energy storage operation during frequency modulation, so the energy storage AGC combined power grid frequency modulation system of the embodiment may further include an electric energy output module to output the energy of the energy storage device, so as to ensure that the stored energy of the energy storage device is always maintained at 45% -65% of the maximum stored energy.

Therefore, the energy storage AGC combined power grid frequency modulation system of the embodiment performs overshoot operation on the actual power grid power through the energy storage device of the carbon-based capacitor battery, so that the actual power grid power can quickly reach the target power grid power, and the occurrence of power regulation delay, power regulation deviation and reverse power regulation is avoided.

According to the national energy agency, the AGC regulation performance is measured by Kp, which is defined as the product of the regulation rate index K1, the regulation accuracy index K2 and the response time index K3, that is, Kp-K1K 2K 3.

The utility model discloses an energy storage AGC unites electric wire netting frequency modulation system can increase substantially regulation rate and response time index, also improves the regulation precision index simultaneously.

If the utility model discloses an energy storage AGC unites electric wire netting frequency modulation system has 330 MW's generating set and 9 MW's energy memory. The improvement to the AGC settling performance is as follows:

first, improvement of the AGC adjustment rate index K1.

The calculation formula of the AGC regulation rate index K1 is as follows:

K1＝2－VN/V1

wherein, VN is the basic speed regulation requirement of the unit (taking 330MW generator set as example VN to define 1.5%/min of the rated power of the unit, i.e. 5MW/min), and V1 is the actual measurement speed of the unit participating in the AGC frequency modulation operation process.

The energy storage device can provide both charge and discharge regulation capability with peak power of-9 MW (charge) and +9MW (discharge). The conditioning time of the energy storage device itself from the nominal charging power to the nominal discharging power (or vice versa) is in the order of seconds. The actual adjustment time in the implemented project is smaller than 5S, that is, the energy storage device can complete the power adjustment of 18MW within 5 seconds. Therefore, the system and the generator set are operated jointly, and the overall regulation rate of the system power can be greatly improved. By integrating various factors of actual AGC frequency modulation, the joint operation rate can be ensured to be not lower than 9MW/min after the energy storage device is accessed, and the corresponding rate regulation index K1 is not lower than 1.5.

And II, improving the AGC response time index K3.

The AGC response time index K3 is used for the response time of the generator set jumping out of a regulation dead zone (defined as 1% of the rated capacity of the generator set) after receiving an AGC command, and the calculation formula is as follows:

K3＝2－ti/tN

and tN is the response time of the unit and is 1min, and ti is the actual response time of the unit in the AGC frequency modulation operation process. The energy storage device is configured to have 9MW peak power far larger than the unit regulation dead zone. The quick and accurate output adjusting capability of the energy storage device can ensure that the total response time of the system is controlled within 20S and the corresponding response time index K3 is not lower than 1.67 even if communication, sampling and control delay of each link is considered.

And thirdly, improving the AGC regulation precision index K2.

The AGC adjustment precision index K2 is used for checking the steady-state tracking error of the generator set to the AGC command, and the calculation formula is as follows:

K2＝2－△P/DN

wherein DN is the basic accuracy requirement of the unit and is 1% of the rated capacity of the unit, and Delta P is the average value of the deviation between the actual output of the unit and the AGC command after the unit enters the steady state. The output adjustment error of the energy storage device is less than 3% of the rated power of the stored energy and is far less than the value required by the rated adjustment precision of the generator set. In the combined operation process, the energy storage device can effectively compensate the steady-state regulation error of the generator set, and the regulation precision index K2 is improved to be more than 1.7.

And fourthly, improving the AGC regulation performance index KP.

Based on the existing energy storage configuration scheme, the AGC regulation performance index KP of the combined operation of the energy storage device and the generator set can reach more than 4.0(K1 is more than 1.5, K2 is more than 1.7, and K3 is more than 1.67). Traditional thermal power generating unit KP will reach this numerical value, need generating set's the load rate of rising to guarantee for a long time more than 3% or keep very big adjustment feedforward volume, if move like this for a long time, will cause the wearing and tearing of equipment such as unit adjustment, coal pulverizer, influence unit safety and stability operation, in addition, the unit frequently changes the power and lower load operation all can lead to the coal consumption to increase.

For a mature energy storage device, within a rated power range, the output of specified power can be finished within 1min with the precision of more than 99%, and the comprehensive response capability of the device can completely meet the power conversion requirement within AGC frequency modulation time. Research reports of the national laboratory of the northwest Pacific (PNNL) in 2008 in the united states show that the frequency modulation effect of the energy storage device is 1.4 times that of a hydroelectric generating set, 2.3 times that of a natural gas generating set and more than 20 times that of a coal generating set. The 10MW energy storage device only needs 2min from +10MW to-10 MW. The actual AGC curve C of the energy storage device almost coincides with the AGC command curve D of the power grid, namely the problems of reverse adjustment, deviation adjustment, delay adjustment and the like can not occur. As shown in particular in figure 3.

The utility model also provides a power grid frequency modulation method uses foretell energy storage AGC to unite electric wire netting frequency modulation system and carries out the electric wire netting frequency modulation, please refer to figure 4 and figure 5, and figure 4 is for using the utility model discloses an energy storage AGC unites electric wire netting frequency modulation system and carries out the flow schematic diagram of electric wire netting frequency modulation, figure 5 is the utility model discloses an energy storage AGC unites electric wire netting frequency modulation system's generating set, energy memory and output electric wire netting's power adjustment schematic diagram. The power grid frequency modulation method comprises the following steps:

step S401, generating a power grid AGC instruction by power grid dispatching equipment;

step S402, if the power grid AGC command is a power boosting command and the power boosting speed set by the power grid AGC command is greater than the maximum set power adjusting speed of the generator set, turning to step S403; if the power grid AGC command is a power boost command and the power boost speed set by the power grid AGC command is less than or equal to the maximum set power regulation speed of the generator set, turning to step S406; if the power grid AGC command is a power reduction command and the power reduction speed set by the power grid AGC command is greater than the maximum set power regulation speed of the generator set, turning to step S407; if the power grid AGC command is a power reduction command and the power reduction speed set by the power grid AGC command is less than or equal to the maximum set power regulation speed of the generator set, turning to step S410;

step S403, the power grid dispatching equipment controls the generator set to be in a generating power lifting state through the generator set distributed control equipment, and the power grid dispatching equipment controls the energy storage device to release energy to an output power grid through the energy storage distributed control equipment (the energy storage device is in a discharging state); the output power of the output power grid is improved based on the power grid AGC command; subsequently, go to step S404;

step S404, the power grid dispatching equipment controls the generator set to be in a power generation high-power fluctuation state through the generator set distributed control equipment, and the power grid dispatching equipment controls the energy storage device to store energy from the output power grid through the energy storage distributed control equipment (the energy storage device is in a charging state); the charging energy is shown as area a in fig. 5, which is equivalent to the discharging energy of the energy storage device in step S403; the output power grid is converted from the output power improvement to the output stable high power based on the power grid AGC command; subsequently, go to step S405;

step S405, the power grid dispatching equipment controls the generator set to be in a stable power generation high power state through the generator set distributed control equipment, and the power grid dispatching equipment controls the energy storage device to be in a standby state through the energy storage distributed control equipment; and outputting the stable high power by the power grid based on the power grid AGC instruction.

And step S406, the generator set independently completes the adjustment of the output electric energy corresponding to the power grid AGC command, and the output power grid outputs stable high power based on the power grid AGC command.

Step S407, the power grid dispatching equipment controls the generator set to be in a power generation power reduction state through the generator set distributed control equipment, and the power grid dispatching equipment controls the energy storage device to store energy from an output power grid through the energy storage distributed control equipment (the energy storage device is in a charging state); the output power grid reduces the output power based on the power grid AGC command; subsequently, the process goes to step S408.

Step S408, the power grid dispatching equipment controls the generator set to be in a low-power generating fluctuation state through the generator set distributed control equipment, and the power grid dispatching equipment controls the energy storage device to release energy to an output power grid through the energy storage distributed control equipment (the energy storage device is in a discharging state); the energy of the discharge is shown as region B in fig. 5, which is equivalent to the charging energy of the energy storage device in step S407; the output power grid is converted from the output power reduction to the output stable low power based on the power grid AGC command; subsequently, it goes to step S409.

Step S409, the power grid dispatching equipment controls the generator set to be in a low-power stable state through the generator set distributed control equipment, and the power grid dispatching equipment controls the energy storage device to be in a standby state through the energy storage distributed control equipment; and outputting the stable low power by the power grid based on the power grid AGC command.

And step S410, the generator set independently finishes the adjustment of the output electric energy corresponding to the power grid AGC command, and the output power grid outputs stable low power based on the power grid AGC command.

Thus, the process of using the energy storage AGC to carry out power grid frequency modulation in combination with the power grid frequency modulation system is completed.

The utility model discloses an energy storage AGC unites electric wire netting frequency modulation system and electric wire netting frequency modulation method carries out the overshoot operation to actual electric wire netting power through energy memory to make actual electric wire netting power can reach target electric wire netting power fast, avoided power regulation delay, power regulation deviation and reverse emergence of power regulation; the technical problems that the power regulation delay, the power regulation deviation and the power regulation reversal easily exist in the conventional power grid frequency modulation system and the conventional power grid frequency modulation method are effectively solved.

Also, although the disclosure has been shown and described with respect to one or more implementations, equivalent alterations and modifications will occur to others skilled in the art based upon a reading and understanding of this specification and the annexed drawings. The present disclosure includes all such modifications and alterations, and is limited only by the scope of the appended claims. In particular regard to the various functions performed by the above described components (e.g., elements, resources, etc.), the terms used to describe such components are intended to correspond, unless otherwise indicated, to any component which performs the specified function of the described component (e.g., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated exemplary implementations of the disclosure. In addition, while a particular feature of the disclosure may have been disclosed with respect to only one of several implementations, such feature may be combined with one or more other features of the other implementations as may be desired and advantageous for a given or particular application. Furthermore, to the extent that the terms "includes," has, "" contains, "or variants thereof are used in either the detailed description or the claims, such terms are intended to be inclusive in a manner similar to the term" comprising.

In summary, although the present invention has been disclosed in the foregoing embodiments, the sequence numbers before the embodiments are only used for convenience of description, and do not limit the sequence of the embodiments of the present invention. Furthermore, the above-mentioned embodiments are not intended to limit the present invention, and those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, therefore, the protection scope of the present invention is subject to the scope defined by the claims.

Claims (6)

1. An energy storage AGC combined power grid frequency modulation system is characterized by comprising:

the power grid dispatching equipment is used for generating a power grid AGC instruction based on the power demand so as to generate the rated power of the generator set;

the generator set is used for generating power to output the output power of the generator set;

the energy storage device is used for storing energy and correcting the output power of the generator set by using the stored energy based on the rated power of the generator set;

the unit distributed control equipment is connected with the power grid dispatching equipment and used for driving the generator unit to perform power generation control operation based on the power grid AGC command;

the energy storage distributed control equipment is connected with the power grid dispatching equipment and used for driving the energy storage device to perform energy storage or energy release operation based on the power grid AGC command; and

the output power grid is respectively connected with the generator set and the energy storage device and used for outputting electric energy corresponding to the power consumption demand based on the corrected output power of the generator set;

the energy storage device comprises a plurality of groups of carbon-based capacitor batteries and corresponding current transformers.

2. The energy storage AGC combined power grid frequency modulation system according to claim 1, wherein the energy storage device is a carbon-based capacitor battery, and the energy storage power of the energy storage device is 2% -3% of the rated power of the generator set.

3. The energy storage AGC combined grid frequency modulation system according to claim 2, wherein the initial stored energy of the energy storage device is 45% -65% of the maximum stored energy.

4. The energy storage AGC grid tuning system of claim 1, further comprising:

and the output detection device is respectively connected with the power grid dispatching equipment, the generator set and the energy storage device, is used for detecting the generator set output energy of the generator set and the battery output energy of the energy storage device, and feeds back the generator set output energy and the battery output energy to the power grid dispatching equipment.

5. The energy storage AGC grid tuning system of claim 1, further comprising:

and the electric energy output module is connected with the energy storage device and used for outputting the energy of the energy storage device.

6. The energy storage AGC combined power grid frequency modulation system according to any one of claims 1-5, wherein the charge-discharge rate of the carbon-based capacitor battery is 10 times to 20 times.

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