A control method for thermal power unit battery capacitor hybrid energy storage technology responding to AGC

Abstract

The invention discloses a control method for a thermal power unit battery capacitor hybrid energy storage technology responding to AGC, the method is a battery capacitor protection working condition control method and an AGC response working condition control method. The battery capacitor protection working condition control method prolongs the service life of the battery capacitor and reduces its unnecessary charging and discharging actions; the AGC response working condition control method is to calculate the basic instructions for the battery capacitor hybrid energy storage action according to the deviation between the AGC load command signal and the actual power signal of the generator, and then calculate the real-time load change rate and the target change rate through the unit load lifting rate signal and the change amount of the generator power measurement value and the variable load action time, perform a series of correction parameters, and examine the difference between the generator power measurement value and the AGC load command in the steady state as small as possible, and through the intelligent upper and lower limit restrictions, the battery capacitor always works in the optimal linear region, improves its availability, and brings greater economic benefits to the thermal power unit using this technology.

Description

Technical Field

[0001] The invention relates to the technical field of thermal power station automatic control, and in particular to a control method for a thermal power unit battery-capacitor hybrid energy storage technology responding to AGC. Background Art

[0002] At present, the AGC function of my country's power system is mainly completed by thermal power units, hydropower units, and new energy units, among which thermal power units account for the largest proportion. However, thermal power units need to go through a series of complex processes to convert primary energy into electrical energy, and the response to AGC instructions needs to take into account many factors, and when the rate reaches a certain value, it is difficult to speed up. Therefore, in order to solve the high requirements of the power grid AGC instructions for each thermal power unit, such as fast regulation rate, high regulation accuracy, and frequent power direction conversion, a more effective means needs to be introduced to achieve this goal.

[0003] Battery-capacitor hybrid energy storage technology is applied in the field of AGC of thermal power units. It has the advantages of fast response speed, precise control and bidirectional regulation capability. It has incomparable advantages over conventional thermal power units in power grid frequency regulation applications. Therefore, in recent years, battery-capacitor hybrid energy storage technology combined with thermal power units for AGC control has gradually been applied in engineering.

[0004] At present, the working mode of the thermal power unit and the battery capacitor hybrid energy storage system jointly responding to AGC is that the unit still responds to the dispatching instruction in the original way, the unit DCS is completely unaffected by the energy storage system, and the energy storage control system determines the charging and discharging according to the power grid instruction and the unit output. The specific process is: after the power grid issues the AGC instruction, the instruction is sent to the RTU device of the power plant where it is located. The RTU device sends the received AGC instruction to the unit DCS system and the energy storage control system at the same time. After receiving the AGC instruction, the unit DCS system immediately controls the unit output to track the dispatching instruction. The energy storage system monitors the unit power in real time. When it receives the AGC instruction, it calculates the output of the energy storage system and then responds quickly. As the unit output responds to the AGC instruction, the energy storage system gradually withdraws and completes a response process.

[0005] The application of battery-capacitor hybrid energy storage technology can indeed solve the AGC response problem of thermal power plants. However, all the energy storage control technologies currently used only consider the response effect to AGC, and the control of the battery capacitor is only a simple charge and discharge instruction. The characteristics of the battery capacitor itself are not considered, causing it to be frequently charged and discharged, resulting in a serious shortening of the battery capacitor's life, which has a great impact on the return on investment of thermal power plants and is not conducive to its long-term and stable promotion. Summary of the invention

[0006] In order to solve the problem of short life of battery capacitor energy storage equipment in the above-mentioned battery capacitor hybrid energy storage technology. The purpose of the present invention is to propose a control method for the battery capacitor hybrid energy storage technology of a thermal power unit in response to AGC, which can fully reduce the number of full charge and discharge times of the battery capacitor under the premise of ensuring that the battery capacitor hybrid energy storage meets the AGC requirements, and maximize the service life of the battery capacitor, improve its availability, and bring greater economic benefits to the thermal power unit using this technology.

[0007] To achieve the above objectives, the present invention is implemented by the following technical solutions:

[0008] A control method for thermal power unit battery capacitor hybrid energy storage technology responding to AGC. The control method is divided into a battery capacitor protection condition control method and an AGC response condition control method by balancing the working characteristics of the battery capacitor and the target of responding to AGC.

[0009] The control method is divided into a battery capacitor protection condition control method and an AGC response condition control method by balancing the working characteristics of the battery capacitor and the target of responding to the AGC. The method is characterized in that, in the battery capacitor protection condition control method, the AGC load command signal is connected to the first function generator, and the battery capacitor energy storage state is connected to the first subtraction operator. After the two are subtracted, they are passed through the second function generator and the first switching selector to finally obtain the required load correction amount and send it to the unit coordination control system. AGC response condition control method, the AGC load instruction and the actual power of the generator are calculated by the second subtraction operator, processed by the third function generator and the fourth function generator respectively, and then calculated by the first multiplication operator to obtain the basic instruction of energy storage action; the unit load rise and fall rate is processed by the fifth function generator, and the basic instruction of energy storage action is corrected once by the calculation of the second multiplication operator; the actual power of the generator is calculated by the inertia operator and the third subtraction operator, and the unit target change rate is calculated by the fourth subtraction operator, processed by the sixth function generator, and finally the basic instruction of energy storage action is corrected twice by the calculation of the third multiplication operator, and this part of the output is the battery capacitor energy storage instruction of the AGC dynamic response; when the unit ends the AGC instruction and enters the steady-state condition, the AGC load instruction and the actual power of the generator are calculated by the fifth subtraction operator, and then calculated by the seventh function generator to form the battery capacitor energy storage instruction of the AGC steady-state response. energy storage instruction; the two instructions are judged by the second selection switch to jointly ensure the responsiveness of the unit to the AGC index; the output of the second selection switch is finally limited by the upper and lower limit operators to form the final hybrid energy storage action instruction; wherein, the upper limit value of the upper and lower limit operator is the output of the third selection switch, and the judgment condition is that the hybrid energy storage power state is monitored by the low signal monitor. When the low power state is triggered, the current value is set to the upper limit value through the operation of the third selection switch, so that the final instruction cannot continue to increase, and the hybrid energy storage device realizes the instruction prohibition increase; the lower limit value of the upper and lower limit operator is the output of the fourth selection switch, and the judgment condition is that the hybrid energy storage power state is monitored by the high signal monitor. When the high power state is triggered, the current value is set to the lower limit value through the operation of the fourth selection switch, so that the final instruction cannot continue to decrease, and the hybrid energy storage device realizes the instruction prohibition reduction, completing the restriction work on the final hybrid energy storage action instruction.

[0010] The battery capacitor protection working condition control method includes: the output of the first function generator is the optimal power of the battery capacitor, the output of the first function generator is the optimal power of the battery capacitor, the output of the first function generator is calculated by the first subtraction operator, the deviation between the two is calculated, the deviation value is processed by the second function generator, and the final load correction value can be obtained, the output of the second function generator is connected to the first switching selector, and the selection and judgment basis is that when the unit ends the last load change for 5 minutes and the unit does not perform the next load change, the unit is considered to be in a stable state, the output value in the stable state is the output value of the second function generator, and the output value in the unstable state is 0, and the final required load correction value is obtained after judgment by the first switching selector and sent to the unit coordination control system.

[0011] AGC response condition control method, AGC load command signal and generator actual power signal are connected to the second subtraction operator, the calculated difference is processed by the third function generator to obtain the battery capacitor energy storage action amount of the deviation between the two, the energy storage device charging and discharging action is mainly based on this function, the fourth function generator connected to the second subtraction operator, the third function generator and the fourth function generator are calculated by the first multiplication operator to obtain the basic energy storage action instruction; the unit load increase and decrease rate signal is set by the operator from the screen, after being processed by the fifth function generator, the basic energy storage action instruction is corrected by the calculation of the second multiplication operator; the actual power of the generator is processed by the inertia operator and the third After the joint calculation of the subtraction operator, the real-time load change rate of the unit can be obtained, and the difference with the target load change rate of the unit is calculated by the fourth subtraction operator. The difference is processed by the sixth function generator and finally calculated by the third multiplication operator to realize the K1 value response of the battery capacitor energy storage device to the AGC; the AGC load instruction and the actual power of the generator are calculated by the fifth subtraction operator, and then calculated by the seventh function generator to form a battery capacitor energy storage instruction for stable AGC response. The two instructions are judged by the second selection switch to jointly ensure the responsiveness of the unit to the AGC index. The selection judgment basis is that when the unit ends the last load change for 5 minutes and the unit has not been The next time the load changes, the unit is considered to be in a stable state, the output value of the stable state is the seventh function generator, the output value of the unstable state is the third multiplication operator, and the output of the second selection switch is finally limited by the upper and lower limit operators to form the final hybrid energy storage action instruction; wherein, the upper limit value of the upper and lower limit operators is the output of the third selection switch, and its judgment condition is that the hybrid energy storage power state is monitored by the low signal monitor, and the trigger condition of the low signal monitor is 30% of the working power of the currently set battery capacitor energy storage device. When the power of the energy storage device is lower than 30% and triggers the low power state, the current value is set as the upper limit value through the judgment of the third selection switch, so that the final instruction The command cannot continue to increase, the battery capacitor energy storage device stops discharging, and when the low power state is not triggered, the upper limit value is 100, that is, there is no limit; the lower limit value of the upper and lower limit operator is the output of the fourth selection switch, and its judgment condition is that the mixed energy storage power state is monitored by the high signal monitor, and the trigger condition of the high signal monitor is 70% of the currently set working power of the battery capacitor energy storage device. When the power of the energy storage device is higher than 70% and the high power state is triggered, the current value is set to the lower limit value through the operation of the fourth selection switch, so that the final command cannot continue to decrease, the battery capacitor energy storage device stops charging, and when the high power state is not triggered, the lower limit value is -100, that is, there is no limit.

[0012] The AGC response working condition control method, the AGC load command signal and the actual power signal of the generator are connected to the second subtraction operator, the calculated difference is processed by the third function generator, and the battery capacitor energy storage action amount of the deviation between the two is obtained. The energy storage device is mainly based on this function when charging and discharging. The fourth function generator connected to the second subtraction operator has the function of dead zone setting, which can make the battery capacitor end its action cycle in advance, reduce its use time, and thus extend its service life to a certain extent. When the deviation between the AGC load command signal and the actual power signal of the generator is less than a certain value, the value is called the load dead zone. After entering the load dead zone, the battery capacitor stops charging and discharging at a certain rate. The third function generator and the fourth function generator are calculated by the first multiplication operator to obtain the basic energy storage action instruction.

[0013] AGC response condition control method, the unit load rise and fall rate signal is set by the operator from the screen, after being processed by the fifth function generator, the basic energy storage action instruction is corrected through the calculation of the second multiplication operator. The correction principle is that the faster the load rise and fall rate, the faster the battery capacitor energy storage device needs to act.

[0014] Considering that the change rate of the K1 value in the AGC index is stable at a target value, when the unit changes load, the real-time load change rate is calculated through the change in the generator power measurement value and the load change action time, and the change rate is compared with the target change rate. If the real-time change rate is slower than the target change rate, the energy storage side performs discharge according to the preset difference logic; if the real-time change rate is faster than the target change rate, the energy storage side performs charging according to the preset difference logic. This design can minimize the action amplitude and number of batteries to ensure the maximization of its service life. The specific implementation method is that the actual power of the generator is calculated by the inertia operator and the third subtraction operator to obtain the real-time load change rate of the unit, and the difference with the target load change rate of the unit is calculated by the fourth subtraction operator. After the difference is processed by the sixth function generator, it is finally calculated by the third multiplication operator to perform secondary correction on the basic energy storage action instruction, so as to realize the K1 value response of the battery capacitor energy storage device to the AGC.

[0015] The AGC response condition control method takes into account the accuracy of the K2 value in the AGC index. This value mainly examines the difference between the generator power measurement value and the AGC load command in the steady state. The smaller the better. The AGC load command and the actual power of the generator are calculated by the fifth subtraction operator, and then the battery capacitor energy storage command of the AGC stable response is formed through the calculation of the seventh function generator. The two instructions are judged by the second selection switch to jointly ensure the unit's responsiveness to the AGC index. The selection and judgment basis is that when the unit ends the last load change for 5 minutes and the unit does not perform the next load change, it is regarded as the unit is in a stable state. The output value of the stable state is the seventh function generator, and the output value of the unstable state is the third multiplication operator.

[0016] The AGC response working condition control method, the output of the second selection switch is finally limited by the upper and lower limit operators to form the final hybrid energy storage action instruction; wherein, the upper limit value of the upper and lower limit operators is the output of the third selection switch, and its judgment condition is that the hybrid energy storage power state is monitored by the low signal monitor, and the trigger condition of the low signal monitor is 30% of the working power of the currently set battery capacitor energy storage device. When the power of the energy storage device is lower than 30% and triggers the low power state, the current value is set as the upper limit value through the judgment of the third selection switch, so that the final instruction cannot continue to increase, and the battery capacitor energy storage device stops discharging. When the low power state is not triggered, the upper limit value is 100, that is, there is no limit; the lower limit value of the upper and lower limit operator is the output of the fourth selection switch, and its judgment condition is that the hybrid energy storage power state is monitored by the high signal monitor, and the trigger condition of the high signal monitor is 70% of the working power of the currently set battery capacitor energy storage device. When the power of the energy storage device is higher than 70% and the high power state is triggered, the current value is set to the lower limit value through the operation of the fourth selection switch, so that the final instruction cannot continue to decrease, and the battery capacitor energy storage device stops charging. When the high power state is not triggered, the lower limit value is -100, that is, there is no limit.

[0017] Compared with the prior art, the present invention has the following advantages:

[0018] 1) Design the battery-capacitor hybrid energy storage protection control function, combined with the optimal linear working area of ​​the battery capacitor, so that it can work in the effective area for a long time and extend the service life of the battery capacitor as much as possible.

[0019] 2) According to the needs of the grid AGC, reasonable power instructions and load feedback are formed. On the one hand, within the dead zone of the grid adjustment assessment, the instruction difference is reset to zero to avoid meaningless charging and discharging of the energy storage; on the other hand, under the condition of maximizing the auxiliary service benefits, the over-output of the energy storage is limited, thereby extending the life of the energy storage device.

[0020] 3) Design control methods for the K1, K2, and K3 values ​​of the AGC assessment, and use battery-capacitor hybrid energy storage technology to achieve AGC response.

[0021] 4) Actively adjust the DCS load setting according to parameters such as the level of energy storage, medium- and long-term load increase and decrease command expectations, and the start and stop status of the unit's coal mill, thereby actively supplementing or releasing the energy storage.

[0022] 5) According to the operating characteristics of the target unit, rationally select the control mode to release the ability of electric energy storage to assist in improving the safety, stability, energy saving and economy of the unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Logic diagram of the battery capacitor protection working condition control method;

[0024] Figure 2 Logic diagram of AGC response condition control method. DETAILED DESCRIPTION

[0025] Among them, the battery capacitor protection working condition control method includes a first function generator connected to the AGC load command signal and a first subtraction operator connected to the battery capacitor energy storage state. After subtracting the two, the signals are passed through a second function generator and a first switching selector to finally obtain the required load correction amount and send it to the unit coordination control system.

[0026] The AGC load command signal and the battery capacitor energy storage quantity status signal come from the unit and the battery capacitor energy storage unit respectively, and are both conventional status signals, which are well known in the art.

[0027] The AGC response condition control method includes: the AGC load instruction and the actual power of the generator are calculated by the second subtractor 5, processed by the third function generator 6 and the fourth function generator 7 respectively, and then calculated by the first multiplier 8 to obtain the basic instruction of energy storage action; the unit load rise and fall rate is processed by the fifth function generator 9, and the basic instruction of energy storage action is corrected once by the calculation of the second multiplier 10; the actual power of the generator is calculated by the inertia operator 12 and the third subtractor 13, and the target change rate of the unit is calculated by the fourth subtractor 14, processed by the sixth function generator 15, and finally the basic instruction of energy storage action is corrected twice by the calculation of the third multiplier 11, and the output of this part is the battery capacitor energy storage instruction of the AGC dynamic response; when the unit ends the AGC instruction and enters the steady-state condition, the AGC load instruction and the actual power of the generator are calculated by the fifth subtractor 17, and then calculated by the seventh function generator 18 to form the battery capacitor energy storage instruction of the AGC steady-state response. Capacitor energy storage instruction; the two instructions are judged by the second selection switch 16 to jointly ensure the responsiveness of the unit to the AGC index; the output of the second selection switch 16 is finally limited by the upper and lower limit operator 19 to form the final hybrid energy storage action instruction; wherein, the upper limit value of the upper and lower limit operator 19 is the output of the third selection switch 21, and its judgment condition is that the hybrid energy storage power state is monitored by the low signal monitor 20. When the low power state is triggered, the current value is set to the upper limit value through the operation of the third selection switch 21, so that the final instruction cannot continue to increase, and the hybrid energy storage device realizes the instruction prohibition increase; the lower limit value of the upper and lower limit operator 19 is the output of the fourth selection switch 23, and its judgment condition is that the hybrid energy storage power state is monitored by the high signal monitor 22. When the high power state is triggered, the current value is set to the lower limit value through the operation of the fourth selection switch 23, so that the final instruction cannot continue to decrease, and the hybrid energy storage device realizes the instruction prohibition reduction, completing the restriction work on the final hybrid energy storage action instruction.

[0028] The AGC load command signal, generator actual power signal, load rise and fall rate signal, and unit target change rate signal are all conventional status signals and are well known in the art.

[0029] The battery capacitor protection condition control method comprehensively considers that the battery capacitor has an optimal linear working area. In order to extend the service life of the battery capacitor as much as possible, it is necessary to reduce its unnecessary charging and discharging actions. In the battery capacitor protection condition control method, the first function generator 1 connected to the AGC load instruction is used to set the optimal linear working area that conforms to its characteristics in combination with the characteristics of the battery capacitor. It can be set to a unit load of 40%-100% rated power, corresponding to a battery capacitor charge of 70%-40%, so that the battery capacitor can maintain the charging and discharging work in the most efficient range for a long time, avoid full charging and discharging, and extend its service life. In summary, the first function generator 1 is set to:

[0030] Table 1 Unit load-battery capacitance correspondence table

[0031] Load(MW) 40 70 100 Power(%) 70 55 40

[0032] The output of the first function generator 1 is the optimal power of the battery capacitor, which is calculated by the first subtraction operator 2 with the battery capacitor energy storage power state signal to calculate the deviation between the two. The deviation value is processed by the second function generator 3 to obtain the final load correction amount. The design principle of the second function generator 3 is: when the battery capacitor energy storage capacity is lower than the optimal capacity, it indicates that it needs to be charged. At this time, the required load correction amount is calculated through the function and sent to the coordinated control system of the unit. After the steam turbine master control in the coordinated control system receives the positive superposition instruction, it makes its final load instruction higher than the actual power of the generator. At this time, the steam turbine master control will issue a turbine adjustment action instruction to increase the actual power of the generator to the superimposed load instruction value. At the same time, due to the increase in the actual power of the generator and the unchanged AGC load instruction signal of the unit itself, the actual power value of the generator received by the battery capacitor energy storage side will be higher than the AGC load instruction signal it receives. Due to the deviation between the two, the battery capacitor starts to charge. When the battery capacitor energy storage capacity is charged to the optimal capacity of the battery capacitor, the control loop will cancel the load instruction superimposed on the DCS side, and the battery capacitor completes the charging work of this steady-state condition, and the system returns to stability; when the battery capacitor energy storage capacity is higher than the optimal capacity, it indicates It needs to discharge, and at this time, the required load correction amount is calculated by the function and sent to the coordinated control system of the unit. After the steam turbine master control in the coordinated control system receives the negative superposition instruction, its final load instruction is lower than the actual power of the generator. At this time, the steam turbine master control will issue a turbine control valve closing action instruction to reduce the actual power of the generator to the superimposed load instruction value. At the same time, due to the reduction of the actual power of the generator and the unchanged AGC load instruction signal of the unit, the actual power value of the generator received by the battery capacitor energy storage side will be lower than the AGC load instruction signal it receives. Due to the deviation between the two, the battery capacitor begins to discharge. When the battery capacitor energy storage capacity is discharged to the optimal capacity of the battery capacitor, the control loop cancels the load instruction superimposed on the DCS side, and the battery capacitor completes the discharge work of this steady-state condition, and the system returns to stability; the turbine control valve action instruction control of the above-mentioned unit coordinated control system is a conventional design in this field and belongs to common knowledge; in summary, the second function generator 3 is set as:

[0033] Table 2 Battery Capacity Deviation-Load Correction Correspondence Table

[0034] Battery capacitance deviation (%) -30 -20 -10 10 20 30 Load correction (MW) -15 -10 -5 5 10 15

[0035] The output of the second function generator 3 is connected to the first switching selector 4, and its selection and judgment basis is that when the unit ends the last load change for 5 minutes and the unit does not perform the next load change, the unit is considered to be in a stable state. The output value in the stable state is the output value of the second function generator 3, and the output value in the unstable state is 0. After judgment by the first switching selector 4, the final required load correction amount is obtained and sent to the unit coordination control system, completing the action of returning the battery capacitor to the optimal linear working area, thereby protecting the battery capacitor.

[0036] In the AGC response working condition control method, the AGC load command signal and the actual power signal of the generator are connected to the second subtraction operator 5, and the calculated difference is processed by the third function generator 6 to obtain the battery capacitor energy storage action amount of the deviation between the two. The energy storage device mainly acts according to this function when charging and discharging, so the third function generator 6 is set as:

[0037] Table 3 Load command deviation-battery capacitor energy storage action amount correspondence table

[0038] Load command deviation(MW) -50 -30 -10 10 30 50 Battery capacitor energy storage action amount (%) -20 -10 -5 5 10 20

[0039] The fourth function generator 7 connected to the second subtractor 5 has the function of setting the dead zone, which can make the battery capacitor end its action cycle in advance, reduce its use time, and thus extend its service life to a certain extent. When the deviation between the AGC load command signal and the actual power signal of the generator is less than a certain value, this value is called the load dead zone. After entering the load dead zone, the battery capacitor stops charging and discharging at a certain rate, so the fourth function generator 7 is set as:

[0040] Table 4 Load command deviation - battery capacitor energy storage action correction coefficient correspondence table

[0041]

[0042] The third function generator 6 and the fourth function generator 7 are calculated by the first multiplier 8 to obtain the energy storage action basic instruction.

[0043] The unit load lifting rate signal is set by the operator from the screen. After being processed by the fifth function generator 9, the energy storage action basic instruction is corrected by the calculation of the second multiplier 10. The correction principle is that the faster the load lifting rate is, the faster the action of the battery capacitor energy storage device needs to be. The fifth function generator 9 is set as:

[0044] Table 5 Unit load rise and fall rate - battery capacitor energy storage action correction coefficient correspondence table

[0045]

[0046] Considering that the K1 value change rate in the AGC index is stable at a target value, when the unit changes load, the real-time load change rate is calculated by the change in the generator power measurement value and the load change action time, and the change rate is compared with the target change rate. If the real-time change rate is slower than the target change rate, the energy storage side performs discharge according to the preset difference logic; if the real-time change rate is faster than the target change rate, the energy storage side performs charging according to the preset difference logic. This design can minimize the action amplitude and number of batteries to ensure the maximization of its service life. The specific implementation method is that the actual power of the generator is calculated by the inertia operator 12 and the third subtraction operator 13 to obtain the real-time load change rate of the unit, and the difference with the target load change rate of the unit is calculated by the fourth subtraction operator 14. After the difference is processed by the sixth function generator 15, the energy storage action basic instruction is corrected twice by the calculation of the third multiplication operator 11 to realize the K1 value response of the battery capacitor energy storage device to the AGC. The sixth function generator 15 is set to:

[0047] Table 6 Unit load change rate deviation - battery capacitor energy storage action correction coefficient correspondence table

[0048]

[0049]

[0050] Considering the accuracy of the K2 value in the AGC index, this value mainly examines the difference between the generator power measurement value and the AGC load command in the steady state, the smaller the better. After the AGC load command and the actual power of the generator are calculated by the fifth subtraction operator 17, the battery capacitor energy storage command of the AGC stable response is formed through the calculation of the seventh function generator 18. The seventh function generator 18 is set to:

[0051] Table 7 Load command deviation-battery capacitor energy storage action correspondence table

[0052]

[0053] The two instructions are judged by the second selection switch 16 to jointly ensure the unit's responsiveness to the AGC index. The selection and judgment basis is that when the unit has completed the last load change for 5 minutes and the unit has not performed the next load change, the unit is considered to be in a stable state. The output value of the stable state is the seventh function generator 18, and the output value of the unstable state is the third multiplier 11.

[0054] The output of the second selection switch 16 is finally limited by the upper and lower limit operator 19 to form the final hybrid energy storage action instruction; wherein, the upper limit value of the upper and lower limit operator 19 is the output of the third selection switch 21, and its judgment condition is that the hybrid energy storage power state is monitored by the low signal monitor 20, and the trigger condition of the low signal monitor 20 is 30% of the working power of the currently set battery capacitor energy storage device. When the power of the energy storage device is lower than 30% and triggers the low power state, the current value is set as the upper limit value through the judgment of the third selection switch 21, so that the final instruction cannot continue to increase, and the battery capacitor energy storage device stops discharging and is not triggered. When the low power state is triggered, the upper limit value is 100, that is, there is no limit; the lower limit value of the upper and lower limit operator 19 is the output of the fourth selection switch 23, and its judgment condition is that the hybrid energy storage power state is monitored by the high signal monitor 22, and the trigger condition of the high signal monitor 22 is 70% of the working power of the currently set battery capacitor energy storage device. When the power of the energy storage device is higher than 70% and the high power state is triggered, the current value is set to the lower limit value through the operation of the fourth selection switch 23, so that the final instruction cannot be further reduced, and the battery capacitor energy storage device stops charging. When the high power state is not triggered, the lower limit value is -100, that is, there is no limit.

Claims

1. A control method for the battery-capacitor hybrid energy storage technology of a thermal power unit responding to AGC, which takes into account the working characteristics of the battery capacitor and the target of responding to AGC, and divides the control method into a battery capacitor protection condition control method and an AGC response condition control method, characterized in that: The battery capacitor protection working condition control method comprises a first function generator connected to the AGC load instruction signal and a first subtraction operator connected to the battery capacitor energy storage state. After the two are subtracted, the two are passed through a second function generator and a first switching selector to finally obtain the required load correction amount and send it to the unit coordination control system. The AGC response working condition control method comprises: the AGC load instruction and the actual power of the generator are calculated by the second subtraction operator, processed by the third function generator and the fourth function generator respectively, and then calculated by the first multiplication operator to obtain the basic energy storage action instruction; the unit load rise and fall rate is processed by the fifth function generator, and the basic energy storage action instruction is corrected once by the calculation of the second multiplication operator; the actual power of the generator is calculated by the inertia operator and the third subtraction operator, and is calculated by the fourth subtraction operator with the unit target change rate, processed by the sixth function generator, and finally the basic energy storage action instruction is corrected twice by the calculation of the third multiplication operator. The output of this part is the battery capacitor energy storage instruction of the AGC dynamic response; when the unit ends the AGC instruction and enters the steady-state working condition, the AGC After the load command and the actual power of the generator are calculated by the fifth subtraction operator, the battery capacitor energy storage command of the AGC steady-state response is formed through the calculation of the seventh function generator; the two instructions are judged by the second selection switch to jointly ensure the responsiveness of the unit to the AGC index; the output of the second selection switch is finally limited by the upper and lower limit operators to form the final hybrid energy storage action command; wherein, the upper limit value of the upper and lower limit operator is the output of the third selection switch, and its judgment condition is that the hybrid energy storage power state is monitored by the low signal monitor. When the low power state is triggered, the current value is set to the upper limit value through the operation of the third selection switch, so that the final instruction cannot continue to increase, and the hybrid energy storage device realizes the instruction prohibition increase; the lower limit value of the upper and lower limit operator is the output of the fourth selection switch, and its judgment condition is that the hybrid energy storage power state is monitored by the high signal monitor. When the high power state is triggered, the current value is set to the lower limit value through the operation of the fourth selection switch, so that the final instruction cannot continue to decrease, and the hybrid energy storage device realizes the instruction prohibition reduction, completing the restriction work on the final hybrid energy storage action instruction.

2. According to claim 1, a control method for the battery-capacitor hybrid energy storage technology response AGC of a thermal power unit is characterized in that: The battery capacitor protection working condition control method includes: the output of the first function generator is the optimal power of the battery capacitor, the output of the first function generator is the optimal power of the battery capacitor, the output of the first function generator is calculated by the first subtraction operator, the deviation between the two is calculated, the deviation value is processed by the second function generator, and the final load correction value can be obtained, the output of the second function generator is connected to the first switching selector, and the selection and judgment basis is that when the unit ends the last load change for 5 minutes and the unit does not perform the next load change, the unit is considered to be in a stable state, the output value in the stable state is the output value of the second function generator, and the output value in the unstable state is 0, and the final required load correction value is obtained after judgment by the first switching selector and sent to the unit coordination control system.

3. The control method of the battery-capacitor hybrid energy storage technology response AGC of a thermal power unit according to claim 1, characterized in that: AGC response condition control method, AGC load command signal and generator actual power signal are connected to the second subtraction operator, the calculated difference is processed by the third function generator to obtain the battery capacitor energy storage action amount of the deviation between the two, the energy storage device charging and discharging action is mainly based on this function, the fourth function generator connected to the second subtraction operator, the third function generator and the fourth function generator are calculated by the first multiplication operator to obtain the basic energy storage action instruction; the unit load increase and decrease rate signal is set by the operator from the screen, after being processed by the fifth function generator, the basic energy storage action instruction is corrected by the calculation of the second multiplication operator; the actual power of the generator is processed by the inertia operator and the third After the joint calculation of the subtraction operator, the real-time load change rate of the unit can be obtained, and the difference with the target load change rate of the unit is calculated by the fourth subtraction operator. The difference is processed by the sixth function generator and finally calculated by the third multiplication operator to realize the K1 value response of the battery capacitor energy storage device to the AGC; the AGC load instruction and the actual power of the generator are calculated by the fifth subtraction operator, and then calculated by the seventh function generator to form a battery capacitor energy storage instruction for stable AGC response. The two instructions are judged by the second selection switch to jointly ensure the responsiveness of the unit to the AGC index. The selection judgment basis is that when the unit ends the last load change for 5 minutes and the unit has not been The next time the load changes, the unit is considered to be in a stable state, the output value of the stable state is the seventh function generator, the output value of the unstable state is the third multiplication operator, and the output of the second selection switch is finally limited by the upper and lower limit operators to form the final hybrid energy storage action instruction; wherein, the upper limit value of the upper and lower limit operators is the output of the third selection switch, and its judgment condition is that the hybrid energy storage power state is monitored by the low signal monitor, and the trigger condition of the low signal monitor is 30% of the working power of the currently set battery capacitor energy storage device. When the power of the energy storage device is lower than 30% and triggers the low power state, the current value is set as the upper limit value through the judgment of the third selection switch, so that the final instruction The command cannot continue to increase, the battery capacitor energy storage device stops discharging, and when the low power state is not triggered, the upper limit value is 100, that is, there is no limit; the lower limit value of the upper and lower limit operator is the output of the fourth selection switch, and its judgment condition is that the mixed energy storage power state is monitored by the high signal monitor, and the trigger condition of the high signal monitor is 70% of the currently set working power of the battery capacitor energy storage device. When the power of the energy storage device is higher than 70% and the high power state is triggered, the current value is set to the lower limit value through the operation of the fourth selection switch, so that the final command cannot continue to decrease, the battery capacitor energy storage device stops charging, and when the high power state is not triggered, the lower limit value is -100, that is, there is no limit.

4. The control method of a thermal power unit battery capacitor hybrid energy storage technology response AGC according to claim 1, characterized in that: The AGC response working condition control method, the AGC load command signal and the actual power signal of the generator are connected to the second subtraction operator, the calculated difference is processed by the third function generator, and the battery capacitor energy storage action amount of the deviation between the two is obtained. The energy storage device is mainly based on this function when charging and discharging. The fourth function generator connected to the second subtraction operator has the function of dead zone setting, which can make the battery capacitor end its action cycle in advance, reduce its use time, and thus extend its service life to a certain extent. When the deviation between the AGC load command signal and the actual power signal of the generator is less than a certain value, the value is called the load dead zone. After entering the load dead zone, the battery capacitor stops charging and discharging at a certain rate. The third function generator and the fourth function generator are calculated by the first multiplication operator to obtain the basic energy storage action instruction.

5. The control method of the battery-capacitor hybrid energy storage technology response AGC of a thermal power unit according to claim 1, characterized in that: AGC response condition control method, the unit load rise and fall rate signal is set by the operator from the screen, after being processed by the fifth function generator, the basic energy storage action instruction is corrected through the calculation of the second multiplication operator. The correction principle is that the faster the load rise and fall rate, the faster the battery capacitor energy storage device needs to act.

6. A control method for a thermal power unit battery-capacitor hybrid energy storage technology in response to AGC according to claim 1, characterized in that: Considering that the change rate of the K1 value in the AGC index is stable at a target value, when the unit changes load, the real-time load change rate is calculated through the change in the generator power measurement value and the load change action time, and the change rate is compared with the target change rate. If the real-time change rate is slower than the target change rate, the energy storage side performs discharge according to the preset difference logic; If the real-time change rate is faster than the target change rate, the energy storage side performs charging according to the preset difference logic. This design can minimize the amplitude and number of battery movements to ensure the maximization of its service life. The specific implementation method is that the actual power of the generator is calculated by the inertia operator and the third subtraction operator to obtain the real-time load change rate of the unit. The difference with the target load change rate of the unit is calculated by the fourth subtraction operator. After the difference is processed by the sixth function generator, it is finally calculated by the third multiplication operator to perform a secondary correction on the basic energy storage action instruction, so as to realize the battery capacitor energy storage device to respond to the K1 value of AGC.

7. The control method of the battery-capacitor hybrid energy storage technology response AGC of a thermal power unit according to claim 1, characterized in that: The AGC response condition control method takes into account the accuracy of the K2 value in the AGC index. This value mainly examines the difference between the generator power measurement value and the AGC load command in the steady state. The smaller the better. The AGC load command and the actual power of the generator are calculated by the fifth subtraction operator, and then the battery capacitor energy storage command of the AGC stable response is formed through the calculation of the seventh function generator. The two instructions are judged by the second selection switch to jointly ensure the unit's responsiveness to the AGC index. The selection and judgment basis is that when the unit ends the last load change for 5 minutes and the unit does not perform the next load change, it is regarded as the unit is in a stable state. The output value of the stable state is the seventh function generator, and the output value of the unstable state is the third multiplication operator.

8. The control method of the battery-capacitor hybrid energy storage technology response AGC of a thermal power unit according to claim 1, characterized in that: AGC response working condition control method, the output of the second selection switch is finally limited by the upper and lower limit operators to form the final hybrid energy storage action instruction; wherein, the upper limit value of the upper and lower limit operators is the output of the third selection switch, and its judgment condition is that the hybrid energy storage power state is monitored by the low signal monitor, and the trigger condition of the low signal monitor is 30% of the working power of the currently set battery capacitor energy storage device. When the power of the energy storage device is lower than 30% and the low power state is triggered, the current value is set as the upper limit value through the judgment of the third selection switch, so that the final instruction cannot continue to increase, the battery capacitor energy storage device stops discharging, and when the low power state is not triggered, the upper limit value is 100, that is, it is not limited; The lower limit value of the upper and lower limit operator is the output of the fourth selection switch, and its judgment condition is that the hybrid energy storage power state is monitored by the high signal monitor. The trigger condition of the high signal monitor is 70% of the working power of the currently set battery capacitor energy storage device. When the power of the energy storage device is higher than 70% and the high power state is triggered, the current value is set to the lower limit value through the operation of the fourth selection switch, so that the final instruction cannot be further reduced, and the battery capacitor energy storage device stops charging. When the high power state is not triggered, the lower limit value is -100, that is, there is no limit.

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