Hybrid Energy Storage System and Control Method of Composite Turbine Power Generation System

Abstract

This disclosure provides a hybrid energy storage system and its control method for a hybrid turbine power generation system. The hybrid turbine power generation system includes a power generation system, a control system, and an energy storage system connected in sequence. The energy storage system includes a battery bank and a supercapacitor. The control method is applied to the control system and includes: determining a first bus power of a transmission bus based on a first difference between the output power of the power generation system and the power consumed by a load electrically connected to the energy storage system; dividing the first bus power into a first power and a second power using a filter, and determining a first reference current of the battery bank based on the first power; determining a first output duty cycle based on a second difference between the first reference current and a first actual current of the battery bank; optimizing the first output duty cycle using an optimization algorithm to minimize the first output duty cycle, obtaining a first minimum duty cycle; and determining the power allocated to the battery bank and the supercapacitor based on the first minimum duty cycle.

Description

Technical Field

[0001] This disclosure relates to the technical field of hybrid energy storage in a vehicle waste heat recovery engine series combined turbine power generation system, and more specifically, to a system and control method for hybrid energy storage in a combined turbine power generation system. Background Technology

[0002] Improving the thermal efficiency of internal combustion engines and reducing fuel consumption and emissions are important trends in the industry. Exhaust emissions, as a significant component of energy loss in internal combustion engines, can be utilized to generate electricity through a series-connected composite turbine using waste heat recovery technology, which is a crucial way to improve the overall energy utilization rate of the engine. However, due to the real-time changes in vehicle operating conditions, exhaust energy exhibits significant non-steady-state characteristics. Consequently, turbine power generation systems possess highly volatile, intermittent, and random power generation characteristics. These characteristics severely affect the energy storage structure's ability to absorb generated power, thus impacting the final power generation efficiency. This places higher demands on energy storage structures and control methods.

[0003] Currently, research on the design and control methods of energy storage structures to address the high volatility and other characteristics of power generation is mostly focused on wind power generation. A hybrid energy storage device, constructed by combining battery banks and supercapacitors, consists of a wind turbine (converting wind energy into mechanical energy), a permanent magnet direct-drive synchronous generator (converting mechanical energy into electrical energy output), a turbine-side converter (composed of an uncontrolled rectifier circuit and a switching power supply circuit, converting AC to DC), a grid-side converter (composed of an insulated-gate bipolar transistor three-phase fully controlled inverter bridge, converting DC to AC for wind power grid connection), battery banks, supercapacitors, and two sets of bidirectional DC / DC converters. The battery energy storage system employs a power and current dual closed-loop control strategy, while the supercapacitor energy storage system employs a voltage and current dual closed-loop control strategy, thereby achieving smooth wind power output and improving low-voltage fault ride-through capability. However, it is mainly a passive control strategy, which does not actively limit the charging / discharging current and voltage, nor does it predict the output of the duty cycle modulation signal based on the energy storage structure margin, and there are problems in monitoring the operation of the energy storage structure and managing its service life. Summary of the Invention

[0004] To address at least one of the technical problems in the prior art, embodiments of this disclosure provide a hybrid energy storage system and its control method for a composite turbine power generation system, which can adjust the power allocated to the battery pack and the power of the supercapacitor based on the operating conditions of the energy storage system, thereby improving the overall performance of the energy storage system.

[0005] This disclosure provides a control method for hybrid energy storage in a hybrid turbine power generation system. The hybrid turbine power generation system includes a power generation system, a control system, and an energy storage system connected in sequence. The energy storage system is electrically connected to the control system via a transmission bus. The energy storage system includes a battery pack and a supercapacitor. The control method is applied to the control system and includes: determining a first bus power of the transmission bus based on a first difference between the output power of the power generation system and the power consumed by a load electrically connected to the energy storage system; dividing the first bus power into a first power and a second power using a filter, and determining a first reference current of the battery pack based on the first power; determining a first output duty cycle based on a second difference between the first reference current and a first actual current of the battery pack; optimizing the first output duty cycle using an optimization algorithm to minimize the first output duty cycle, obtaining a first minimum duty cycle; and determining the power allocated to the battery pack and the supercapacitor based on the first minimum duty cycle.

[0006] According to some embodiments of this disclosure, determining the power allocated to the battery pack and the power allocated to the supercapacitor based on the first minimum duty cycle includes: adjusting the power allocated to the battery pack by controlling the filter based on the first minimum duty cycle; and determining the power allocated to the supercapacitor based on the power of the battery pack.

[0007] According to some embodiments of this disclosure, when the power of the first bus is positive, the energy storage system charges from the transmission bus; when the power of the first bus is negative, the energy storage system discharges to the transmission bus.

[0008] According to some embodiments of this disclosure, the above-mentioned method of using a filter to divide the first bus power into a first power and a second power, and determining the first reference current of the battery pack based on the first power, includes: obtaining the first reference current based on the first power and the first real-time voltage of the battery pack.

[0009] According to some embodiments of this disclosure, determining the first output duty cycle based on the second difference between the first reference current and the first actual current of the battery pack includes: using a predictive model controller to obtain a first modulation signal matching the second difference based on the second difference; and using a pulse modulation generator to obtain the first output duty cycle matching the first modulation signal based on the first modulation signal.

[0010] According to some embodiments of this disclosure, the optimization of the first output duty cycle using an optimization algorithm to minimize the first output duty cycle and obtain the first minimum duty cycle includes: obtaining the second reference current of the transmission bus at the (k+i+1)th time based on the second bus power and the second real-time voltage of the transmission bus at the (k+i+1)th time, where k is a positive integer and i = 0, 1, 2, 3...; predicting the third actual current of the battery pack at the (k+i+1)th time based on the second reference current and the second actual current of the battery pack at the kth time according to the optimization algorithm; determining the second output duty cycle at the (k+i+1)th time based on the third difference between the third actual current and the second actual current, wherein the second output duty cycle is less than the first output duty cycle; and determining the second output duty cycle as the first minimum duty cycle when the second output duty cycle meets a predetermined condition.

[0011] According to some embodiments of this disclosure, the prediction of the third actual current of the battery pack at time k+i+1 based on the second reference current and the second actual current of the battery pack at time k, according to the optimization algorithm, includes: predicting the third actual current using the following formula: ;in, This is expressed as the weight of the bus current of the aforementioned transmission bus. This is represented as the fourth actual current at the (k+i+1)th time of the aforementioned transmission bus. This refers to the second reference current at the (k+i+1)th time of the aforementioned transmission bus. This is expressed as the weight of the reference current of the aforementioned battery pack. This is expressed as the third actual current of the aforementioned battery pack at the (k+i+1)th time. Let i be the second actual current of the battery pack at time k, where k is a positive integer and i = 0, 1, 2, 3, ...

[0012] According to some embodiments of this disclosure, determining the second output duty cycle at time k+i+1 based on the third difference between the third actual current and the second actual current includes: using the prediction model controller to obtain a second modulation signal matching the third difference based on the third difference; and using the pulse modulation generator to obtain the second output duty cycle matching the second modulation signal based on the second modulation signal.

[0013] According to some embodiments of this disclosure, the power generation system includes an exhaust valve, an exhaust gas turbine, an exhaust gas turbine bypass valve, a power turbine, a power turbine bypass valve, and a generator set; gas enters the power generation system through the exhaust valve; the exhaust gas turbine is connected to the exhaust valve, the exhaust gas turbine bypass valve is connected in parallel with the exhaust gas turbine, and the exhaust gas turbine pressurizes the gas as it flows through the exhaust gas turbine; the power turbine is connected in series with the exhaust turbine, the power turbine bypass valve is connected in parallel with the power turbine, and the power turbine, after receiving the pressurized gas, drives the generator set coaxially connected to the power turbine, thereby generating electricity. The control method further includes: opening the power turbine bypass valve when the power of the battery pack is greater than or equal to a predetermined charging power.

[0014] According to some embodiments of another aspect of this disclosure, a hybrid energy storage system for a composite turbine power generation system is provided, suitable for implementing the above-described control method for hybrid energy storage in a composite turbine power generation system. The composite turbine power generation system includes a power generation system, a control system, and an energy storage system connected in sequence. The energy storage system is electrically connected to the control system via a transmission bus. The energy storage system includes a battery pack and a supercapacitor. The control system includes: a first determining module, configured to determine a first bus power of the transmission bus based on a first difference between the output power of the power generation system and the power consumed by a load electrically connected to the energy storage system; a second determining module, configured to divide the first bus power into a first power and a second power using a filter, and determine a first reference current of the battery pack based on the first power; a third determining module, configured to determine a first output duty cycle based on a second difference between the first reference current and a first actual current of the battery pack; an optimization module, configured to optimize the first output duty cycle using an optimization algorithm to minimize the first output duty cycle, obtaining a first minimum duty cycle; and an adjustment module, configured to determine the power allocated to the battery pack and the supercapacitor based on the first minimum duty cycle.

[0015] According to an embodiment of this disclosure, a hybrid energy storage system and its control method for a hybrid turbine power generation system include a power generation system, a control system, and an energy storage system connected in sequence. The energy storage system is electrically connected to the control system via a transmission bus. The energy storage system includes a battery bank and a supercapacitor. The control method is applied to the control system. Based on a first difference between the output power of the power generation system and the power consumed by the load electrically connected to the energy storage system, a first bus power of the transmission bus is determined. The first bus power is divided into a first power and a second power using a filter. Based on the first power, a first reference current of the battery bank is determined. Based on a second difference between the first reference current and the first actual current of the battery bank, a first output duty cycle is determined. The first output duty cycle is optimized using an optimization algorithm to minimize the first output duty cycle, resulting in a first minimum duty cycle. Based on the first minimum duty cycle, the power allocated to the battery bank and the power of the supercapacitor are determined. This method can adjust the power allocated to the battery bank and the power of the supercapacitor in conjunction with the operating conditions of the energy storage system, thereby improving the overall performance of the energy storage system. Attached Figure Description

[0016] Figure 1 This is a flowchart of a control method for hybrid energy storage in a combined turbine power generation system according to an illustrative embodiment of the present disclosure;

[0017] Figure 2 This is a block diagram of a hybrid energy storage system of a composite turbine power generation system according to an illustrative embodiment of the present disclosure;

[0018] Figure 3 This is a block diagram of an optimized control strategy for a hybrid energy storage system charge / discharge and predictive model controller according to an illustrative embodiment of the present disclosure;

[0019] Figure 4 This is a flowchart of a sub-step for determining the first output duty cycle according to an illustrative embodiment of the present disclosure;

[0020] Figure 5 This is a flowchart of the sub-steps for obtaining a first minimum duty cycle according to an illustrative embodiment of the present disclosure;

[0021] Figure 6 This is a flowchart of a sub-step for determining the second output duty cycle at time k+i+1 according to an illustrative embodiment of the present disclosure;

[0022] Figure 7 This is a block diagram of a control system according to an illustrative embodiment of the present disclosure;

[0023] Figure 8 This is a block diagram of an electronic device for a control method of hybrid energy storage for a composite turbine power generation system according to an illustrative embodiment of the present disclosure.

[0024] In the accompanying drawings, the meanings of the reference numerals are as follows:

[0025] 1. Engine;

[0026] 2. Intercooler;

[0027] 3. Air compressor;

[0028] 4. Exhaust gas turbine;

[0029] 5. Power Turbine;

[0030] 6. Power turbine bypass valve;

[0031] 7. Exhaust gas turbine bypass valve;

[0032] 8. Generator set;

[0033] 9. Three-phase bridge fully controlled rectifier;

[0034] 10. Maximum power point tracking controller;

[0035] 11. DC-DC converter;

[0036] 12. Transmission busbar;

[0037] 13. Vehicle load;

[0038] 14. Bidirectional DC-DC converter for battery packs;

[0039] 15. Supercapacitor bidirectional DC-DC converter;

[0040] 16. Hybrid energy storage system charge / discharge and predictive model controller;

[0041] 17. Supercapacitor;

[0042] 18. Battery pack;

[0043] 19. Filter;

[0044] 20. Predictive model controller;

[0045] 21. Pulse modulation generator. Detailed Implementation

[0046] The embodiments of the present disclosure will now be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the disclosure. In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments of the present disclosure for ease of explanation. However, it will be apparent that one or more embodiments may be practiced without these specific details. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concepts of the present disclosure.

[0047] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0048] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0049] When using expressions such as "at least one of A, B, and C," the expression should generally be interpreted in accordance with the meaning commonly understood by a person skilled in the art (e.g., "a system having at least one of A, B, and C" should include, but is not limited to, systems having A alone, having B alone, having C alone, having A and B, having A and C, having B and C, and / or having A, B, and C, etc.). When using expressions such as "at least one of A, B, or C," the expression should generally be interpreted in accordance with the meaning commonly understood by a person skilled in the art (e.g., "a system having at least one of A, B, or C" should include, but is not limited to, systems having A alone, having B alone, having C alone, having A and B, having A and C, having B and C, and / or having A, B, and C, etc.).

[0050] Existing technologies focus primarily on wind power smoothing and improving low-voltage fault ride-through capability, neglecting the monitoring and control of energy storage system operation and lifespan. To improve power quality and extend the lifespan of energy storage systems, according to one aspect of this disclosure, a composite turbine power generation system includes a power generation system, a control system, and an energy storage system connected sequentially. The energy storage system is electrically connected to the control system via a transmission bus. The energy storage system includes a battery bank and a supercapacitor. A control method is applied to the control system, determining the transmission bus based on a first difference between the output power of the power generation system and the power consumption of the load electrically connected to the energy storage system. The first bus power is divided into a first power and a second power using a filter. Based on the first power, a first reference current for the battery pack is determined. Based on the second difference between the first reference current and the first actual current of the battery pack, a first output duty cycle is determined. The first output duty cycle is optimized using an optimization algorithm to minimize it, resulting in a first minimum duty cycle. Based on the first minimum duty cycle, the power allocated to the battery pack and the power allocated to the supercapacitor are determined. This allows for adjustments to the power allocated to the battery pack and the supercapacitor based on the operating conditions of the energy storage system, thereby improving the overall performance of the energy storage system.

[0051] Figure 1 This is a flowchart of a control method for hybrid energy storage in a combined turbine power generation system according to an illustrative embodiment of the present disclosure. Figure 2 This is a block diagram of a hybrid energy storage system of a composite turbine power generation system according to an illustrative embodiment of the present disclosure.

[0052] A control method for hybrid energy storage in a combined turbine power generation system is provided according to embodiments of this disclosure, such as... Figure 2 As shown, the composite turbine power generation system includes a power generation system, a control system, and an energy storage system connected in sequence. The energy storage system is electrically connected to the control system via the transmission bus 12. The energy storage system includes a battery pack 18 and a supercapacitor 17. The control method is applied to the control system, such as... Figure 1 As shown, the control method includes the following steps S1 to S5.

[0053] Step S1: Determine the first bus power of the transmission bus 12 based on the first difference between the output power of the power generation system and the power consumed by the load electrically connected to the energy storage system.

[0054] According to embodiments of this disclosure, based on the output power P of the power generation system output The power consumption P of the load (vehicle load 13) electrically connected to the energy storage system load The first difference between them is calculated using the following formula (1) to determine the first bus power P of transmission bus 12. m :

[0055] P m =P output -P load (1).

[0056] Step S2: Use filter 19 to divide the first bus power into first power and second power, and determine the first reference current of battery pack 18 based on the first power.

[0057] Step S3: Determine the first output duty cycle based on the second difference between the first reference current and the first actual current of the battery pack 18.

[0058] Step S4: Optimize the duty cycle of the first output using an optimization algorithm to minimize the duty cycle of the first output, thus obtaining the first minimum duty cycle.

[0059] Step S5: Determine the power allocated to the battery pack 18 and the supercapacitor 17 based on the first minimum duty cycle.

[0060] According to embodiments of this disclosure, the power generation system includes an engine 1, an intercooler 2, a compressor 3, an exhaust valve, an exhaust turbine 4, an exhaust turbine bypass valve 7, a power turbine 5, a power turbine bypass valve 6, and a generator set 8. Gas enters the power generation system through the exhaust valve. The engine 1 converts chemical energy into thermal energy. The intercooler 2 reduces the gas temperature, increases the intake air density of the engine 1, and improves the performance and efficiency of the engine 1. The compressor 3 increases the gas pressure, improving the power and torque of the engine 1. The exhaust turbine 4 is connected to the exhaust valve. The exhaust turbine bypass valve 7 is connected in parallel with the exhaust turbine 4. The exhaust turbine bypass valve 7 regulates whether exhaust gas flows through the exhaust turbine 4. The exhaust turbine 4 pressurizes the gas as it flows through it. The power turbine 5 is connected in series with the exhaust turbine 4, and the power turbine bypass valve 6 is connected in parallel with the power turbine 5. The power turbine bypass valve 6 is used to regulate whether the exhaust gas flows through the power turbine 5 (whether it generates electricity). The power turbine 5 is used to convert thermal energy into mechanical energy. After receiving the pressurized gas, the power turbine 5 drives the generator set 8, which is coaxially connected to the power turbine 5, so that the generator set 8 generates electricity. The generator set 8 is used to convert mechanical energy into electrical energy and then output it.

[0061] According to embodiments of this disclosure, the control system is located at the starting end of the transmission bus 12. The control system includes a three-phase bridge fully controlled rectifier 9 (AC / DC), a maximum power point tracking controller 10 (MPPT controller), and a DC / DC converter 11. The three-phase bridge fully controlled rectifier 9 is used to convert three-phase alternating current to direct current and to acquire the DC side current and voltage (IC). dc U dc This is to achieve DC voltage regulation. The MPPT controller is used to output the optimal duty cycle d with the DC side current and voltage as the signal. opDC-DC converter 11 is used for voltage conversion and initial stabilization.

[0062] According to embodiments of this disclosure, the energy storage system includes a hybrid energy storage system charge / discharge and predictive model controller 16, a battery pack bidirectional DC / DC converter 14, a battery pack 18, a supercapacitor bidirectional DC / DC converter 15, and a supercapacitor 17. The hybrid energy storage system charge / discharge and predictive model controller 16 is used to determine the charging or discharging state based on predicted limits according to the demand of the transmission bus 12 or the power released by the transmission bus 12, and to control the battery pack bidirectional DC / DC converter 14 and the supercapacitor bidirectional DC / DC converter 15. The battery pack bidirectional DC / DC converter 14 and the supercapacitor bidirectional DC / DC converter 15 are used for voltage conversion during charging or discharging. The battery pack 18 and the supercapacitor 17 are used to store output electrical energy. The battery pack 18 and the supercapacitor 17 are connected to the transmission bus 12 through the battery pack bidirectional DC-DC converter 14 (DC / DC) and the supercapacitor bidirectional DC-DC converter 15 (DC / DC), respectively. The hybrid energy storage system charge / discharge and prediction model controller 16 monitors the power required by the transmission bus 12 in real time, predicts and controls the current and voltage limits and charging or discharging margin of the energy storage system, thereby improving the efficiency, stability and flexibility of the energy storage system and extending its service life.

[0063] According to embodiments of this disclosure, the battery pack 18 can be a lead-acid battery pack or a lithium battery pack, which has advantages such as high energy density, long energy storage time, and relatively mature technology. However, this device, which achieves energy storage based on redox catalytic reaction, has disadvantages such as slow charging and discharging speed, low power density, and short cycle life. Affected by the vehicle's operating state, the exhaust energy of engine 1 exhibits non-steady-state characteristics, so its turbine power generation system has highly volatile, intermittent, and random power generation characteristics. Therefore, an energy storage element with high power density and fast dynamic response speed is needed. Supercapacitors (SC), as a power-type energy storage element, have advantages such as high power density, fast response speed, strong release capacity, large depth of charge and discharge, and long cycle life, but they have problems such as low energy density. In summary, the supercapacitor 17 and the battery pack 18 complement each other, and combining them into a hybrid energy storage system (HESS) can improve the stability, flexibility, and efficiency of the energy storage element. This disclosure introduces the hybrid energy storage system into the field of vehicle waste heat recovery turbine power generation energy storage.

[0064] According to embodiments of this disclosure, a composite turbine power generation system includes a power generation system, a control system, and an energy storage system connected in sequence. The energy storage system is electrically connected to the control system via a transmission bus 12. The energy storage system includes a battery pack 18 and a supercapacitor 17. A control method is applied to the control system. Based on a first difference between the output power of the power generation system and the power consumed by the load electrically connected to the energy storage system, a first bus power of the transmission bus 12 is determined. The first bus power is divided into a first power and a second power using a filter 19. Based on the first power, a first reference current of the battery pack 18 is determined. Based on a second difference between the first reference current and the first actual current of the battery pack 18, a first output duty cycle is determined. The first output duty cycle is optimized using an optimization algorithm to minimize the first output duty cycle, resulting in a first minimum duty cycle. Based on the first minimum duty cycle, the power allocated to the battery pack 18 and the supercapacitor 17 is determined. This allows for adjustment of the power allocated to the battery pack 18 and the supercapacitor 17 in conjunction with the operating conditions of the energy storage system, thereby improving the overall performance of the energy storage system.

[0065] According to embodiments of this disclosure, when the power of the first bus is positive, the energy storage system charges from the transmission bus 12. When the power of the first bus is negative, the energy storage system discharges to the transmission bus 12.

[0066] According to an embodiment of this disclosure, based on the first bus power P of the transmission bus 12 m The positive or negative value determines the operating status of the charge / discharge controller of the hybrid energy storage system. At the first bus power P... m When the value is positive, the energy storage system charges from transmission bus 12. At the first bus power P... m When the value is negative, the energy storage system discharges to the transmission bus 12, supplying power to the vehicle together with the generator set 8. At the first bus power P... m If the value is zero, then no work is required.

[0067] According to embodiments of this disclosure, based on the first bus power P m and the real-time voltage U of transmission bus 12 m The reference current I of transmission bus 12 is determined by the following formula (2). m_ref :

[0068] I m_ref = (2).

[0069] Figure 3 This is a block diagram of an optimized control strategy for a hybrid energy storage system charge / discharge and predictive model controller 16 according to an illustrative embodiment of the present disclosure.

[0070] According to embodiments of this disclosure, such as Figure 3As shown, filter 19 is used to filter the first bus power P m Divided into first power P L Second power P H And based on the first power P L Determine the first reference current I of battery pack 18. bat_ref Including: based on the first power P L The first reference current is obtained by taking the first real-time voltage of the battery pack 18.

[0071] According to embodiments of this disclosure, filter 19 may be selected as a low-pass filter (LPF).

[0072] According to embodiments of this disclosure, based on a first power P L The first real-time voltage U of the battery pack 18 bat The first reference current I is obtained through the following formula (3). bat_ref :

[0073] I bat_ref = (3).

[0074] Figure 4 This is a flowchart of a sub-step for determining the first output duty cycle according to an illustrative embodiment of the present disclosure.

[0075] According to embodiments of this disclosure, such as Figure 4 As shown, based on the first reference current I bat_ref and the first actual current I of battery pack 18 bat The second difference between I bat Determine the first output duty cycle d bat It includes the following steps S31 to S32.

[0076] Step S31: Using the prediction model controller 20, based on the second difference I bat A first modulation signal m that matches the second difference is obtained. bat .

[0077] According to embodiments of this disclosure, the first reference current I bat_ref and the first actual current I of battery pack 18 bat The second difference between I bat It can be expressed by the following formula (4):

[0078] I bat =I bat_ref -I bat (4).

[0079] According to embodiments of this disclosure, the Model Predictive Control (MPC) will use the second difference... I bat As input, the predictive model controller MPC will determine the first real-time voltage U of the battery pack 18. bat and the first actual current I of battery pack 18 bat Whether it is within a given range and cannot exceed a given limit is expressed by the following formulas (5) and (6):

[0080] U bat_min <U bat <U bat_max (5);

[0081] I bat_min <I bat <I bat_ max (6).

[0082] Step S32: Using the pulse modulation (PWM) generator 21, based on the first modulation signal m bat , to obtain the first modulation signal m bat Matching first output duty cycle d bat The first modulation signal m bat and the first output duty cycle d bat The relationship can be expressed by the following formula (7):

[0083] m bat =1-d bat (7).

[0084] Figure 5 This is a flowchart of a sub-step for obtaining a first minimum duty cycle according to an illustrative embodiment of the present disclosure.

[0085] According to embodiments of this disclosure, such as Figure 5 As shown, the first output duty cycle d is optimized using an optimization algorithm. bat Optimize to make the first output duty cycle d bat Minimizing the first minimum duty cycle involves the following steps S41 to S44.

[0086] Step S41: Based on the power of the second bus at time k+i+1 of transmission bus 12 The second real-time voltage at time k+i+1 of transmission bus 12 The second reference current I at the (k+i+1)th time of transmission bus 12 is obtained. m_ref (k+i+1), where k is a positive integer and i = 0, 1, 2, 3, ...

[0087] According to an embodiment of this disclosure, the second reference current I at the (k+i+1)th moment of the transmission bus 12 is calculated using the following formula (8). m_ref (k+i+1):

[0088] I m_ref (k+i+1)= (8).

[0089] Step S42: Based on the second reference current and the second actual current of the battery pack 18 at time k, predict the third actual current of the battery pack 18 at time k+i+1 according to the optimization algorithm.

[0090] According to embodiments of this disclosure, based on the second reference current and the second actual current of the battery pack 18 at time k, the prediction of the third actual current of the battery pack 18 at time k+i+1 according to the optimization algorithm includes: predicting the third actual current using the following formula (9):

[0091] (9);

[0092] Where J represents the objective function to be minimized. This represents the weight of the bus current of transmission bus 12. This represents the fourth actual current at time k+i+1 of transmission bus 12. This represents the second reference current at time k+i+1 of transmission bus 12. This represents the weight of the reference current for battery pack 18. This represents the third actual current at time k+i+1 of battery pack 18. Let i be the second actual current at time k of the battery pack 18, where k is a positive integer and i = 0, 1, 2, 3, ...

[0093] According to embodiments of this disclosure, the weighting of the bus current of transmission bus 12 is adjusted. Weighting of the reference current of battery pack 18 The predictive model controller (MPC) will predict the third actual current of battery pack 18 at time k+i+1 in real time at time k. The fourth actual current at time k+i+1 of transmission bus 12 The greater the weight, the smaller the response of the battery pack 18 to current fluctuations. The remaining excessive current fluctuations are responded to by the supercapacitor 17, thus smoothing the power fluctuations of the power generation system.

[0094] Step S43: Based on the third actual current Second actual current The third difference between Ibat (k+i+1), determine the second output duty cycle d at time k+i+1. bat (k+i+1), where the second output duty cycle d bat (k+i+1) is less than the first output duty cycle d bat .

[0095] According to embodiments of this disclosure, the third actual current Second actual current The third difference between I bat (k+i+1) can be expressed by the following formula (10):

[0096] I bat (k+i+1)=I bat (k+i+1)-I bat (k)(10).

[0097] Figure 6 This is a flowchart of a sub-step for determining the second output duty cycle at time k+i+1 according to an illustrative embodiment of the present disclosure.

[0098] According to embodiments of this disclosure, such as Figure 6 As shown, based on the third actual current Second actual current The third difference between I bat (k+i+1), determine the second output duty cycle d at time k+i+1. bat (k+i+1) includes the following steps S431 to S432.

[0099] Step S431: Using the predictive model controller 20, based on the third difference I bat (k+i+1), obtain the difference with the third value I bat The second modulation signal m that matches (k+i+1) bat (k+i+1).

[0100] Simultaneously, considering the given margin SOC (State of Charge), which is 10%~90%, the second modulation signal m bat (k+i+1) must be expressed within the limit range using the following formula (11):

[0101] m bat_min <m bat (k+i+1)<m bat_ max (11).

[0102] Step S432: Using the pulse modulation generator 21, based on the second modulation signal m bat (k+i+1), to obtain the second modulation signal m bat The second output duty cycle d that matches (k+i+1) bat (k+i+1).

[0103] According to embodiments of this disclosure, the second modulation signal m bat (k+i+1) and the second output duty cycle d bat The relationship of (k+i+1) can be expressed by the following formula (12):

[0104] m bat (k+i+1)=1-d bat (k+i+1)(12).

[0105] Step S44: In the second output duty cycle d bat If (k+i+1) satisfies the predetermined conditions, the second output duty cycle d will be adjusted. bat (k+i+1) is determined as the first minimum duty cycle.

[0106] According to embodiments of this disclosure, the control method further includes opening the power turbine bypass valve 6 when the power of the battery pack 18 is greater than or equal to a predetermined charging power.

[0107] According to embodiments of this disclosure, when the power of the battery pack 18 is greater than or equal to the charging limit, the power turbine bypass valve 6 is opened to achieve a second output duty cycle d. bat (k+i+1) Effective control of the MPPT controller.

[0108] According to an embodiment of this disclosure, determining the power allocated to the battery pack 18 and the power allocated to the supercapacitor 17 based on a first minimum duty cycle includes: adjusting the power allocated to the battery pack 18 by controlling the filter 19 based on the first minimum duty cycle, and then determining the power allocated to the supercapacitor 17 based on the power of the battery pack 18.

[0109] According to the embodiments of this disclosure, based on the first minimum duty cycle, the power (low frequency) allocated to the battery pack 18 is adjusted by the control filter 19, and then the power (high frequency) allocated to the supercapacitor 17 is determined according to the power of the battery pack 18, thereby realizing optimal power allocation, that is, the battery pack 18 absorbs or releases low frequency power, and the supercapacitor 17 absorbs or releases high frequency power, so that the engine 1 can output the optimal power generation to the power transmission bus 12 under any operating condition.

[0110] According to embodiments of this disclosure, for the supercapacitor 17 side, firstly based on the second power P Hand the third real-time voltage U of supercapacitor 17 sc The third reference current I is obtained through the following formula (13). sc_ref :

[0111] I sc_ref = (13).

[0112] According to embodiments of this disclosure, the third reference current I sc_ref And the fifth actual current I of supercapacitor 17 sc The fourth difference between I sc It can be expressed by the following formula (14):

[0113] I sc =I sc_ref -I sc (14).

[0114] According to embodiments of this disclosure, the Model Predictive Control (MPC) will use the fourth difference... I sc As input, the predictive model controller MPC will determine the third real-time voltage U of the supercapacitor 17. sc And the fifth actual current I of supercapacitor 17 sc Whether it is within a given range and cannot exceed a given limit is expressed by the following formulas (15) and (16):

[0115] U sc_min <U sc <U sc_max (15);

[0116] I sc_min <I sc <I sc_ max (16).

[0117] According to embodiments of this disclosure, a predictive model controller 20 is used, based on a fourth difference. I sc The difference between the fourth and fifth values ​​is obtained. I sc Matching third modulation signal m sc .

[0118] Simultaneously, considering the given margin SOC (State of Charge), which is 10%~90%, the third modulation signal m sc It must be expressed within the limit range using the following formula (17):

[0119] m sc_min <msc <m sc_ max (17).

[0120] According to embodiments of this disclosure, a pulse modulation generator 21 is used, based on a third modulation signal m sc The third modulation signal m is obtained. sc Matching third output duty cycle d sc The third modulation signal m sc and the third output duty cycle d sc The relationship can be expressed by the following formula (18):

[0121] m sc =1-d sc (18).

[0122] According to embodiments of this disclosure, when the power of the supercapacitor 17 is greater than or equal to the charging limit, the power turbine bypass valve 6 is opened to achieve a third output duty cycle d. sc Effective control of the MPPT controller.

[0123] According to embodiments of this disclosure, by actively limiting the current and voltage of charging or discharging through an optimized control strategy based on a power allocation outer loop and a margin prediction limit inner loop, the energy storage system can track the demand power or released power of the transmission bus 12 in real time, reducing energy storage losses and suppressing power fluctuations in the power generation system. Furthermore, this method also limits the current and voltage of the energy storage system, effectively controls the charging or discharging margin, and predicts the output of the modulation signal corresponding to the duty cycle based on the margin, reducing overcharging and over-discharging, enabling monitoring of the energy storage system's operation, extending its service life, and ultimately improving the overall performance of the energy storage system.

[0124] According to embodiments of this disclosure, this disclosure combines the complementary advantages of battery pack 18 and supercapacitor 17 to construct an energy storage system and introduce it into the field of vehicle waste heat recovery turbine power generation energy storage, so as to achieve optimal power distribution, that is, battery pack 18 absorbs or releases low-frequency power, and supercapacitor 17 absorbs or releases high-frequency power, thereby solving the problem that the energy storage components of the composite turbine power generation system need to have high power density and fast dynamic response speed due to the high volatility, intermittency and randomness of the power generation characteristics.

[0125] Figure 7 This is a block diagram of a control system according to an illustrative embodiment of the present disclosure.

[0126] According to another embodiment of this disclosure, a hybrid energy storage system for a composite turbine power generation system is provided, suitable for implementing the above-described control method for hybrid energy storage in a composite turbine power generation system. The composite turbine power generation system includes a power generation system, a control system, and an energy storage system connected in sequence. The energy storage system is electrically connected to the control system via a transmission bus 12. The energy storage system includes a battery pack 18 and a supercapacitor 17. Figure 7 As shown, the control system 700 includes a first determining module 710, a second determining module 720, a third determining module 730, an optimization module 740, and an adjustment module 750.

[0127] According to an embodiment of this disclosure, the first determining module 710 is used to determine the first bus power of the transmission bus 12 based on a first difference between the output power of the power generation system and the power consumed by the load electrically connected to the energy storage system. In one embodiment, the first determining module 710 may be used to perform step S1 described above, which will not be repeated here.

[0128] According to embodiments of this disclosure, the second determining module 720 is used to divide the first bus power into a first power and a second power using the filter 19, and to determine a first reference current of the battery pack 18 based on the first power. In one embodiment, the second determining module 720 may be used to perform step S2 described above, which will not be repeated here.

[0129] According to embodiments of this disclosure, the third determining module 730 is used to determine the first output duty cycle based on a second difference between the first reference current and the first actual current of the battery pack 18. In one embodiment, the third determining module 730 may be used to perform step S3 described above, which will not be repeated here.

[0130] According to embodiments of this disclosure, the optimization module 740 is used to optimize the first output duty cycle using an optimization algorithm, thereby minimizing the first output duty cycle to obtain a first minimum duty cycle. In one embodiment, the optimization module 740 may be used to execute step S4 described above, which will not be repeated here.

[0131] According to embodiments of this disclosure, the adjustment module 750 is used to determine the power allocated to the battery pack 18 and the supercapacitor 17 based on a first minimum duty cycle. In one embodiment, the adjustment module 750 may be used to perform step S5 as described above, which will not be repeated here.

[0132] According to embodiments of the present invention, any plurality of modules among the first determining module 710, the second determining module 720, the third determining module 730, the optimization module 740, and the adjustment module 750 may be combined into one module, or any one of these modules may be split into multiple modules. Alternatively, at least a portion of the functionality of one or more of these modules may be combined with at least a portion of the functionality of other modules and implemented in one module. According to embodiments of the present invention, at least one of the first determining module 710, the second determining module 720, the third determining module 730, the optimization module 740, and the adjustment module 750 may be at least partially implemented as hardware circuitry, such as a field-programmable gate array (FPGA), a programmable logic array (PLA), a system-on-a-chip, a system-on-a-substrate, a system-on-package, an application-specific integrated circuit (ASIC), or any other reasonable means of integrating or packaging circuitry, or implemented in software, hardware, or firmware, or in any one of the three implementation methods, or in a suitable combination of any of them. Alternatively, at least one of the first determining module 710, the second determining module 720, the third determining module 730, the optimization module 740, and the adjustment module 750 may be implemented at least partially as a computer program module, which can perform corresponding functions when the computer program module is run.

[0133] Figure 8 This is a block diagram of an electronic device for a control method of hybrid energy storage for a composite turbine power generation system according to an illustrative embodiment of the present disclosure. Figure 8 The electronic device shown is merely an example and should not be construed as limiting the functionality and scope of the embodiments disclosed herein.

[0134] like Figure 8 As shown, an electronic device 800 according to an embodiment of this disclosure includes a processor 801, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 802 or a program loaded from a storage portion 808 into a random access memory (RAM) 803. The processor 801 may include, for example, a general-purpose microprocessor (e.g., a CPU), an instruction set processor and / or an associated chipset and / or a special-purpose microprocessor (e.g., an application-specific integrated circuit (ASIC)), etc. The processor 801 may also include onboard memory for caching purposes. The processor 801 may include a single processing unit or multiple processing units for performing different actions of the method flow according to an embodiment of this disclosure.

[0135] RAM 803 stores various programs and data required for the operation of electronic device 800. Processor 801, ROM 802, and RAM 803 are interconnected via bus 804. Processor 801 performs various operations of the method flow according to embodiments of the present disclosure by executing programs in ROM 802 and / or RAM 803. It should be noted that the programs may also be stored in one or more memories other than ROM 802 and RAM 803. Processor 801 may also perform various operations of the method flow according to embodiments of the present disclosure by executing programs stored in said one or more memories.

[0136] According to embodiments of this disclosure, the electronic device 800 may further include an input / output (I / O) interface 805, which is also connected to a bus 804. The electronic device 800 may also include one or more of the following components connected to the input / output (I / O) interface 805: an input section 806 including a keyboard, mouse, etc.; an output section 807 including a cathode ray tube (CRT), liquid crystal display (LCD), etc., and a speaker, etc.; a storage section 808 including a hard disk, etc.; and a communication section 809 including a network interface card such as a LAN card, modem, etc. The communication section 809 performs communication processing via a network such as the Internet. A drive 810 is also connected to the input / output (I / O) interface 805 as needed. A removable medium 811, such as a disk, optical disk, magneto-optical disk, semiconductor memory, etc., is installed on the drive 810 as needed so that computer programs read from it can be installed into the storage section 808 as needed.

[0137] This disclosure also provides a computer-readable storage medium, which may be included in the device / apparatus / system described in the above embodiments; or it may exist independently and not assembled into the device / apparatus / system. The computer-readable storage medium carries one or more programs, which, when executed, implement the control method according to the embodiments of this disclosure.

[0138] According to embodiments of this disclosure, the computer-readable storage medium can be a non-volatile computer-readable storage medium, such as including, but not limited to: portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In this disclosure, the computer-readable storage medium can be any tangible medium that contains or stores a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. For example, according to embodiments of this disclosure, the computer-readable storage medium may include ROM 802 and / or RAM 803 and / or one or more memories other than ROM 802 and RAM 803 described above.

[0139] Embodiments of this disclosure also include a computer program product comprising a computer program containing program code for performing the methods shown in the flowchart. When the computer program product is run on a computer system, the program code is used to cause the computer system to implement the methods provided in the embodiments of this disclosure.

[0140] When the computer program is executed by the processor 801, it performs the functions defined in the system / apparatus of this disclosure embodiments. According to embodiments of this disclosure, the systems, apparatuses, modules, units, etc., described above can be implemented by computer program modules.

[0141] In one embodiment, the computer program may rely on a tangible storage medium such as an optical storage device or a magnetic storage device. In another embodiment, the computer program may also be transmitted and distributed in the form of signals over a network medium, and may be downloaded and installed via the communication section 809, and / or installed from a removable medium 811. The program code contained in the computer program can be transmitted using any suitable network medium, including but not limited to: wireless, wired, etc., or any suitable combination thereof.

[0142] In such an embodiment, the computer program can be downloaded and installed from a network via communication section 809, and / or installed from removable medium 811. When the computer program is executed by processor 801, it performs the functions defined in the system of this disclosure embodiment. According to embodiments of this disclosure, the systems, devices, apparatuses, modules, units, etc., described above can be implemented by computer program modules.

[0143] According to embodiments of this disclosure, program code for executing the computer programs provided in embodiments of this disclosure can be written in any combination of one or more programming languages. Specifically, these computational programs can be implemented using high-level procedural and / or object-oriented programming languages, and / or assembly / machine languages. Programming languages ​​include, but are not limited to, languages ​​such as Java, C++, Python, "C", or similar programming languages. The program code can execute entirely on a user's computing device, partially on a user's device, partially on a remote computing device, or entirely on a remote computing device or server. In cases involving remote computing devices, the remote computing device can be connected to the user's computing device via any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0144] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this disclosure. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram or flowchart, and combinations of blocks in a block diagram or flowchart, may be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0145] Those skilled in the art will understand that the features described in the various embodiments and / or claims of this disclosure can be combined or combined in various ways, even if such combinations or combinations are not explicitly described in this disclosure. In particular, the features described in the various embodiments and / or claims of this disclosure can be combined and / or combined in various ways without departing from the spirit and teachings of this disclosure. All such combinations and / or combinations fall within the scope of this disclosure.

[0146] It should also be noted that the directional terms mentioned in the embodiments, such as "up," "down," "front," "back," "left," and "right," are only for reference to the directions in the accompanying drawings and are not intended to limit the scope of protection of this disclosure. Throughout the drawings, the same elements are represented by the same or similar reference numerals. Conventional structures or constructions will be omitted where they may cause confusion in understanding this disclosure, and the shapes and dimensions of the components in the drawings do not reflect actual size and proportion, but are only schematic representations of the embodiments of this disclosure.

[0147] Unless otherwise stated, the numerical parameters in this specification and the appended claims are approximate values ​​and can be varied according to desired characteristics derived from the content of this disclosure. Specifically, all figures used in the specification and claims to indicate composition, reaction conditions, etc., should be understood to be modified by the term "about" in all cases. Generally, this means that a specific amount may vary by ±10% in some embodiments, ±5% in some embodiments, ±1% in some embodiments, and ±0.5% in some embodiments.

[0148] The use of ordinal numbers such as "first," "second," "third," etc., in the specification and claims to modify the corresponding elements does not imply that the element has any ordinal number, nor does it represent the order of one element with another element, or the order of manufacturing methods. The use of these ordinal numbers is only to enable a named element to be clearly distinguished from another element with the same name.

[0149] Furthermore, unless specifically described or required to occur in a specific order, the order of the above steps is not limited to those listed above and can be varied or rearranged according to the desired design. Moreover, the above embodiments can be used in combination with each other or with other embodiments based on design and reliability considerations; that is, technical features from different embodiments can be freely combined to form more embodiments.

[0150] The embodiments of this disclosure have been described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of this disclosure. Although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. The scope of this disclosure is defined by the appended claims and their equivalents. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of this disclosure, and all such substitutions and modifications should fall within the scope of this disclosure.

Claims

1. A control method for hybrid energy storage in a hybrid turbine power generation system, the hybrid turbine power generation system comprising a power generation system, a control system, and an energy storage system connected in sequence, the energy storage system being electrically connected to the control system via a transmission bus, the energy storage system comprising a battery bank and a supercapacitor, the control method being applied to the control system, the control method comprising: The first bus power of the transmission bus is determined based on a first difference between the output power of the power generation system and the power consumed by the load electrically connected to the energy storage system. The power of the first bus is divided into a first power and a second power using a filter, and a first reference current of the battery pack is determined based on the first power. The first output duty cycle is determined based on the second difference between the first reference current and the first actual current of the battery pack, including: Using a predictive model controller, a first modulation signal matching the second difference is obtained; Using a pulse modulation generator, a first output duty cycle that matches the first modulation signal is obtained based on the first modulation signal; The first output duty cycle is optimized using an optimization algorithm to minimize it, resulting in a first minimum duty cycle. This includes: Based on the second bus power at time k+i+1 and the second real-time voltage of the transmission bus at time k+i+1, the second reference current of the transmission bus at time k+i+1 is obtained, where k is a positive integer and i = 0, 1, 2, 3...; Based on the second reference current and the second actual current of the battery pack at time k, the third actual current of the battery pack at time k+i+1 is predicted according to the optimization algorithm, including: The third actual current is predicted using the following formula: ； Where J represents the objective function to be minimized. This is represented by the weight of the bus current of the transmission bus. This is represented as the fourth actual current of the transmission bus at the (k+i+1)th time. This is represented by the second reference current of the transmission bus at the (k+i+1)th time. The weight is represented by the reference current of the battery pack. The third actual current of the battery pack at time k+i+1 is represented by this value. This is expressed as the second actual current of the battery pack at the k-th moment, where k is a positive integer and i = 0, 1, 2, 3...; Based on the third difference between the third actual current and the second actual current, the second output duty cycle at time k+i+1 is determined, wherein the second output duty cycle is less than the first output duty cycle; If the second output duty cycle meets a predetermined condition, the second output duty cycle is determined as the first minimum duty cycle; The power allocated to the battery pack and the power allocated to the supercapacitor are determined based on the first minimum duty cycle.

2. The control method according to claim 1, wherein, The step of determining the power allocated to the battery pack and the power of the supercapacitor based on the first minimum duty cycle includes: Based on the first minimum duty cycle, the power allocated to the battery pack is adjusted by controlling the filter; The power allocated to the supercapacitor is determined based on the power of the battery pack.

3. The control method according to claim 1, wherein, When the power of the first bus is positive, the energy storage system charges from the transmission bus; When the power of the first bus is negative, the energy storage system discharges to the transmission bus.

4. The control method according to claim 1, wherein, The step of using a filter to divide the first bus power into a first power and a second power, and determining the first reference current of the battery pack based on the first power, includes: The first reference current is obtained based on the first power and the first real-time voltage of the battery pack.

5. The control method according to claim 1, wherein, Determining the second output duty cycle at time k+i+1 based on the third difference between the third actual current and the second actual current includes: Using the prediction model controller, a second modulation signal matching the third difference is obtained based on the third difference; Using the pulse modulation generator, a second output duty cycle that matches the second modulation signal is obtained based on the second modulation signal.

6. The control method according to claim 1, wherein, The power generation system includes an exhaust valve, an exhaust gas turbine, an exhaust gas turbine bypass valve, a power turbine, a power turbine bypass valve, and a generator set. Gas enters the power generation system through the exhaust valve. The exhaust gas turbine is connected to the exhaust valve, and the exhaust gas turbine bypass valve is connected in parallel with the exhaust gas turbine. The exhaust gas turbine pressurizes the gas as it flows through it. The power turbine is connected in series with the exhaust gas turbine, and the power turbine bypass valve is connected in parallel with the power turbine. After receiving the pressurized gas, the power turbine drives the generator set coaxially connected to the power turbine, thereby generating electricity. The control method further includes: When the power of the battery pack is greater than or equal to the predetermined charging power, the power turbine bypass valve is opened.

7. A hybrid energy storage system for a composite turbine power generation system, suitable for implementing the control method for hybrid energy storage in a composite turbine power generation system as described in any one of claims 1 to 6, wherein, The composite turbine power generation system includes a power generation system, a control system, and an energy storage system connected in sequence. The energy storage system is electrically connected to the control system via a transmission bus. The energy storage system includes a battery bank and a supercapacitor. The control system includes: The first determining module is used to determine the first bus power of the transmission bus based on a first difference between the output power of the power generation system and the power consumption of the load electrically connected to the energy storage system; The second determining module is used to divide the first bus power into a first power and a second power using a filter, and to determine the first reference current of the battery pack based on the first power. The third determining module is used to determine the first output duty cycle based on the second difference between the first reference current and the first actual current of the battery pack. The optimization module is used to optimize the duty cycle of the first output using an optimization algorithm, so as to minimize the duty cycle of the first output and obtain the first minimum duty cycle. An adjustment module is used to determine the power allocated to the battery pack and the power of the supercapacitor based on the first minimum duty cycle.

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