Method and device for analyzing output dynamic performance of charging and discharging circuit of energy storage system

Abstract

The invention relates to the technical field of oil field ground system engineering, in particular to a method and device for analyzing output dynamic performance of a charging and discharging circuit of an energy storage system. The method comprises the following steps: acquiring an input voltage, an inductance value, a capacitance value, an output voltage and an output power of a charging and discharging circuit, and determining a conduction time length and a turn-off time length of a power electronic device of the charging and discharging circuit and a maximum amplitude value of an inductive current in the conduction time length according to the input voltage, the inductance value, the capacitance value, the output voltage and the output power; determining the optimal starting time according to the turn-on duration and the turn-off duration of the power electronic device; and analyzing the optimal starting time, the turn-on duration, the turn-off duration and the maximum amplitude of the inductive current in the turn-on time period of the power electronic device, and determining the output dynamic performance of the charging and discharging circuit of the energy storage system. The problem that the dynamic performance of a charging and discharging circuit of an existing energy storage system cannot be accurately analyzed and evaluated, so that the power grid fluctuates and is unstable due to the fact that the charging and discharging speed does not meet the requirement is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of oilfield surface system engineering, and particularly to an analysis method and device for the output dynamic performance of a charge and discharge circuit of an energy storage system. Background Art

[0002] In the oilfield production scenario, with the increasing proportion of new energy power generation, there is also a technical requirement for the application of energy storage devices. With the large-scale integration of renewable energy power generation into the traditional power system, the randomness and volatility of renewable energy power generation have brought non-negligible negative impacts on the stable operation of the power grid. Currently, using the energy compensation of the energy storage system to suppress the energy fluctuation of the power grid has become an effective method to solve this problem.

[0003] To solve the problems of power system fluctuations and poor stability caused by the large-scale integration of new energy power generation into the oilfield power grid, an energy storage system has been applied in the oilfield new energy power generation network. The dynamic performance index of the energy storage system, especially the charge and discharge speed, directly affects the transient stability of the power grid during the energy regulation process. The typical charge and discharge circuit currently used is the buck circuit. How to accurately analyze and evaluate the dynamic response performance of the charge or discharge startup process of the charge and discharge circuit, so as to ensure the stability of the power grid during the system operation, is an urgent problem to be solved at present. Summary of the Invention

[0004] The present invention proposes an analysis method and device for the output dynamic performance of a charge and discharge circuit of an energy storage system, so as to solve the problem that due to the inability to accurately analyze and evaluate the dynamic performance of the charge and discharge circuit of the existing energy storage system, it may cause power grid fluctuations and instability due to the charge and discharge speed not meeting the requirements.

[0005] According to one aspect of the present invention, there is provided an analysis method for the output dynamic performance of a charge and discharge circuit of an energy storage system, including:

[0006] Obtaining the input voltage, inductance value, capacitance value, output voltage, and output power of the charge and discharge circuit;

[0007] Determining the conduction duration, turn-off duration of the power electronic device in the charge and discharge circuit, and the maximum amplitude of the inductor current during the conduction period according to the input voltage, inductance value, capacitance value, output voltage, and output power;

[0008] Determining the optimal startup time according to the conduction duration and turn-off duration of the power electronic device;

[0009] Analyzing the optimal startup time, conduction duration, turn-off duration of the power electronic device, and the maximum amplitude of the inductor current during the conduction period to determine the output dynamic performance of the charge and discharge circuit of the energy storage system.

[0010] Preferably, the method for determining the conduction duration, the turn-off duration of the power electronic device of the charge and discharge circuit, and the maximum amplitude of the inductor current during the conduction period according to the input voltage, the inductor value, the capacitor value, the output voltage, and the output power includes:

[0011] Obtain the relevant parameter formulas of the power electronic device of the charge and discharge circuit during the conduction period, including at least: input electrical energy, inductor energy storage change, capacitor energy storage change, conduction duration, and output energy calculation formulas, and the relevant parameter formulas during the turn-off period, including at least: inductor energy storage change, capacitor energy storage change, turn-off duration, and output energy calculation formulas;

[0012] Determine the first relationship between the input electrical energy, inductor energy storage change, capacitor energy storage change, and output energy during the conduction period, and the second relationship between the inductor energy storage change, capacitor energy storage change, and output energy during the turn-off period;

[0013] According to the first relationship, the second relationship, the relevant parameter formulas during the conduction period, and the relevant parameter formulas during the turn-off period, determine the conduction duration, the turn-off duration of the power electronic device of the charge and discharge circuit, and the maximum amplitude of the inductor current during the conduction period.

[0014] Preferably, the calculation formula for the inductor energy storage change during the turn-off period is:

[0015]

[0016] In the formula: E Loff is the inductor energy storage change during the turn-off period, L is the inductor value, P o is the output power, U o is the output voltage, I L is the maximum amplitude of the inductor current during the conduction period.

[0017] Preferably, the calculation formula for the conduction duration is:

[0018]

[0019] In the formula: T on is the conduction duration, C is the capacitor value, I L is the maximum amplitude of the inductor current during the conduction period, U L is the terminal voltage across the capacitor C corresponding to I L , P o is the output power, U o is the output voltage.

[0020] Preferably, the calculation formula for the turn-off duration is:

[0021]

[0022] Where: T off is the turn-off duration, C is the capacitance value, I L is the maximum amplitude of the inductor current during the conduction period, U L is the terminal voltage across the capacitor C corresponding to I L ; P o is the output power, U o is the output voltage.

[0023] Preferably, the output energy during the conduction period is:

[0024]

[0025] Where: E Oon is the output energy during the conduction period, U L is the terminal voltage across the capacitor C corresponding to the maximum amplitude I of the inductor current during the conduction period L ; P o is the output power, U o is the output voltage, T on is the conduction duration.

[0026] Preferably, the output energy during the turn-off period is:

[0027]

[0028] Where: E Ooff is the output energy during the turn-off period, U L is the terminal voltage across the capacitor C corresponding to the maximum amplitude I of the inductor current during the conduction period L ; P o is the output power, U o is the output voltage, T off is the turn-off duration.

[0029] Preferably, the first relational expression is:

[0030] E in = E Lon + E Con + E Oon ;

[0031] Where: E in is the input electric energy during the conduction period, E Lon is the change in inductor energy storage during the conduction period, E Con is the change in capacitor energy storage during the conduction period, E Oon is the output energy during the conduction period;

[0032] The second relational expression is:

[0033] 0 = E Loff + E Coff + E Ooff ;

[0034] Wherein: E Loff is the change in inductance energy storage during the off - period, E Coff is the change in capacitance energy storage during the off - period, E Ooff is the output energy during the off - period.

[0035] Preferably, the method for determining the optimal start - up time according to the conduction duration and the off - duration of the power electronic device includes:

[0036] Determine the optimal start - up time according to the optimal start - up time calculation formula;

[0037] Wherein, the optimal start - up time calculation formula is:

[0038] T start = T on + T off ;

[0039] Wherein: T start is the optimal start - up time, T on is the conduction duration, T off is the off - duration;

[0040] And / or, the charge - discharge circuit is: Buck circuit.

[0041] According to one aspect of the present invention, there is provided an analysis device for the output dynamic performance of a charge - discharge circuit of an energy storage system, including:

[0042] An acquisition unit for acquiring the input voltage, inductance value, capacitance value, output voltage and output power of the charge - discharge circuit;

[0043] An operation unit for determining the conduction duration, off - duration of the power electronic device of the charge - discharge circuit and the maximum amplitude of the inductor current during the conduction period according to the input voltage, inductance value, capacitance value, output voltage and output power;

[0044] An analysis unit for determining the optimal start - up time according to the conduction duration and the off - duration of the power electronic device; analyzing the optimal start - up time, the conduction duration, the off - duration of the power electronic device and the maximum amplitude of the inductor current during the conduction period to determine the output dynamic performance of the charge - discharge circuit of the energy storage system.

[0045] The present invention has at least the following beneficial effects:

[0046] The present invention provides an analysis method and device for the output dynamic performance of a charge-discharge circuit of an energy storage system. By determining four parameters, namely, the start-up time, conduction duration, turn-off duration, and maximum amplitude of the inductor current of the charge-discharge circuit, it is possible to accurately evaluate the control effect of the control strategy of the charge-discharge circuit, greatly simplify the performance evaluation process, and ensure the stable operation of the power grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The accompanying drawings are incorporated herein and form a part of this specification. These drawings illustrate embodiments consistent with the present invention and, together with the specification, are used to explain the technical solutions of the present invention.

[0048] Figure 1 A flowchart showing an analysis method for the output dynamic performance of a charge-discharge circuit of an energy storage system according to an embodiment of the present invention;

[0049] Figure 2 A schematic structural diagram showing an analysis device for the output dynamic performance of a charge-discharge circuit of an energy storage system according to an embodiment of the present invention.

[0050] In the figure, 1 - input electric energy calculation module, 2 - inductor energy calculation module, 3 - capacitor energy calculation module, 4 - output electric energy calculation module, 5 - solution module, 6 - display module. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0051] Various exemplary embodiments, features, and aspects of the present invention will be described in detail below with reference to the accompanying drawings. The same reference numerals in the drawings denote elements having the same or similar functions. Although various aspects of the embodiments are shown in the drawings, the drawings are not necessarily drawn to scale unless otherwise specified.

[0052] The term "exemplary" used herein means "serving as an example, embodiment, or illustration". Any embodiment described as "exemplary" herein is not necessarily to be construed as superior to or better than other embodiments.

[0053] The term "and / or" as used herein is merely a description of an associated relationship between associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the term "at least one" as used herein means any one of a plurality or any combination of at least two of a plurality. For example, including at least one of A, B, and C can represent including any one or more elements selected from the set composed of A, B, and C.

[0054] In addition, for a better illustration of the present invention, numerous specific details are given in the following detailed implementation manners. Those skilled in the art should understand that the present invention can also be implemented without some specific details. In some instances, methods, means, elements, and circuits well-known to those skilled in the art are not described in detail so as to highlight the gist of the present invention.

[0055] Figure 1 A flowchart showing an analysis method for the output dynamic performance of a charge-discharge circuit of an energy storage system according to an embodiment of the present invention; Figure 2 A schematic structural diagram showing an analysis device for the output dynamic performance of a charge-discharge circuit of an energy storage system according to an embodiment of the present invention. As Figure 1 and 2 shown, an analysis method for the output dynamic performance of a charge-discharge circuit of an energy storage system includes: Step S01: Obtain the input voltage, inductance value, capacitance value, output voltage, and output power of the charge-discharge circuit; Step S02: Determine the conduction duration, turn-off duration of the power electronic device in the charge-discharge circuit, and the maximum amplitude of the inductor current during the conduction period according to the input voltage, inductance value, capacitance value, output voltage, and output power; Step S03: Determine the optimal start time according to the conduction duration and turn-off duration of the power electronic device; Step S04: Analyze the optimal start time, the conduction duration and turn-off duration of the power electronic device, and the maximum amplitude of the inductor current during the conduction period to determine the output dynamic performance of the charge-discharge circuit of the energy storage system.

[0056] The analysis method for the output dynamic performance of a charge-discharge circuit of an energy storage system provided by an embodiment of the present invention specifically includes the following steps:

[0057] Step S01: Obtain the input voltage, inductance value, capacitance value, output voltage, and output power of the charge-discharge circuit.

[0058] In an embodiment of the present invention, taking the buck circuit as an example, its input voltage signal U in , inductance value L, capacitance value C, output voltage signal U o , and output power signal P o are parameters that can be directly obtained during the operation of the buck circuit. According to the above parameters, each parameter for evaluating the output dynamic performance of the charge-discharge circuit can be calculated.

[0059] Step S02: Determine the conduction duration, turn-off duration of the power electronic device in the charge-discharge circuit, and the maximum amplitude of the inductor current during the conduction period according to the input voltage, inductance value, capacitance value, output voltage, and output power.

[0060] In the present invention, the method for determining the conduction duration, the turn-off duration of the power electronic device of the charge and discharge circuit, and the maximum amplitude of the inductor current during the conduction period according to the input voltage, the inductance value, the capacitance value, the output voltage, and the output power includes: obtaining the relevant parameter formulas of the power electronic device of the charge and discharge circuit during the conduction period, including at least: the input electrical energy, the change in inductor energy storage, the change in capacitor energy storage, the conduction duration, and the output energy calculation formula, and the relevant parameter formulas during the turn-off period, including at least: the change in inductor energy storage, the change in capacitor energy storage, the turn-off duration, and the output energy calculation formula; determining the first relationship between the input electrical energy, the change in inductor energy storage, the change in capacitor energy storage, and the output energy during the conduction period, and the second relationship between the change in inductor energy storage, the change in capacitor energy storage, and the output energy during the turn-off period; and determining the conduction duration, the turn-off duration of the power electronic device of the charge and discharge circuit, and the maximum amplitude of the inductor current during the conduction period according to the first relationship, the second relationship, the relevant parameter formulas during the conduction period, and the relevant parameter formulas during the turn-off period.

[0061] In an embodiment of the present invention, the relevant parameter calculation formulas of the power electronic device of the charge and discharge circuit during the conduction period include at least: the input electrical energy E during the conduction period in calculation formula, the change in inductor energy storage E during the conduction period Lon calculation formula, the change in capacitor energy storage E during the conduction period Con calculation formula, the conduction time length (conduction duration) T of the circuit power electronic device on calculation formula, and the output energy E during the conduction period Oon calculation formula. The relevant parameter calculation formulas of the power electronic device of the charge and discharge circuit during the turn-off period include at least: the change in inductor energy storage E during the turn-off period Loff calculation formula, the change in capacitor energy storage E during the turn-off period Coff calculation formula, the turn-off time length (turn-off duration) T of the circuit power electronic device off calculation formula, and the output energy E during the turn-off period Ooff calculation formula.

[0062] According to the input voltage signal U of the buck circuit in , the calculation formula for forming the input electrical energy E during the conduction period is as follows: in The calculation formula is:

[0063]

[0064] Where: U in is the input voltage signal, I L is the maximum current amplitude reached by the inductor current during the conduction of the power electronic device, Ton is the inductor current rise time during the optimal startup process.

[0065] According to the inductor value signal L of the buck circuit, using the energy storage calculation principle of the inductor, the change in inductor energy storage E during the conduction period is formed Lon The calculation formula is:

[0066]

[0067] In the formula: L is the inductor value signal, I L is the maximum current amplitude reached by the inductor current during the conduction process of the power electronic device.

[0068] According to the inductor value signal L and output voltage signal U of the buck circuit o and output power signal P o , using the energy storage calculation principle of the inductor, after the power electronic device changes from conduction to cutoff, the change in inductor energy storage E during the cutoff period of the buck circuit is formed Loff The calculation formula (3).

[0069] In the present invention, the calculation formula for the change in inductor energy storage during the cutoff period is:

[0070]

[0071] In the formula: E Loff is the change in inductor energy storage during the cutoff period, L is the inductor value, P o is the output power, U o is the output voltage, I L is the maximum amplitude of the inductor current during the conduction period.

[0072] According to the capacitor value signal C of the buck circuit, using the capacitor energy storage calculation principle, the change in capacitor energy storage E during the conduction period of the buck circuit is formed Con The calculation formula is:

[0073]

[0074] In the formula: C is the capacitor value, U L is the terminal voltage across the capacitor C corresponding to I L .

[0075] According to the capacitor value signal C and output voltage signal U of the buck circuit o , using the capacitor energy storage calculation principle, after the power electronic device changes from conduction to cutoff, the change in capacitor energy storage E during the cutoff period of the buck circuit is formed Coff The calculation formula is:

[0076]

[0077] Where: C is the capacitance value, U o is the output voltage, U L is the voltage across the capacitor C corresponding to I L

[0078] According to the capacitance value signal C, output voltage signal U o , output power signal P o of the buck circuit, using the charge balance principle of the capacitor, the calculation formula (6) of the conduction time length T on of the power electronic device in the buck circuit is formed.

[0079] In the present invention, the calculation formula of the conduction duration is:

[0080]

[0081] Where: T on is the conduction duration, C is the capacitance value, I L is the maximum amplitude of the inductor current during the conduction period, U L is the voltage across the capacitor C corresponding to I L , P o is the output power, U o is the output voltage.

[0082] According to the capacitance value signal C, output voltage signal U o , output power signal P o of the buck circuit, using the charge balance principle of the capacitor, the calculation formula (7) of the turn-off time length T off of the power electronic device in the buck circuit is formed.

[0083] In the present invention, the calculation formula of the turn-off duration is:

[0084]

[0085] Where: T off is the turn-off duration, C is the capacitance value, I L is the maximum amplitude of the inductor current during the conduction period, U L is the voltage across the capacitor C corresponding to I L , P o is the output power, U o is the output voltage.

[0086] According to the output voltage signal U o , output power signal P o and conduction time length T on ​, form the output energy E during the conduction period of the buck circuit Oon in the calculation formula (8).

[0087] In the present invention, the output energy during the conduction period is:

[0088]

[0089] In the formula: E Oon is the output energy during the conduction period, U L is the terminal voltage across the capacitor C corresponding to the maximum amplitude I L of the inductor current during the conduction period, P o is the output power, U o is the output voltage, T on is the conduction duration.

[0090] According to the output voltage signal U o of the buck circuit, the output power signal P o and the off-time length T off , form the calculation formula (9) of the output energy E Ooff during the conduction period of the buck circuit.

[0091] In the present invention, the output energy during the off period is:

[0092]

[0093] In the formula: E Ooff is the output energy during the off period, U L is the terminal voltage across the capacitor C corresponding to the maximum amplitude I L of the inductor current during the conduction period, P o is the output power, U o is the output voltage, T off is the off duration.

[0094] According to the above formulas (1), (2), (4), (8), based on the principle of energy conservation of the buck circuit during the conduction period of the power electronic device, the first relational expression, that is, formula (10), can be obtained;

[0095] In the present invention, the first relational expression is:

[0096] E in = E Lon + E Con + E Oon (10);

[0097] In the formula: E in is the input electric energy during the conduction period, E Lonis the change in inductor energy storage during the conduction period, E Con E is the change in capacitance energy during the conduction period, Oon Output energy during the conduction period;

[0098] According to the above formulas (3), (5), and (9), the second relationship can be obtained according to the energy conservation principle of the buck circuit during the off time period of the power electronic device, namely formula (11);

[0099] The second relation is:

[0100] 0=E Loff +E Coff +E Ooff (11);

[0101] Where: E Loff is the change in inductor energy storage during the off time period, E Coff E is the change in capacitor energy storage during the off time period, Ooff Output energy during the off time period.

[0102] By combining equations (1) to (11) to form a system of equations, we can solve the conduction time T of the power electronic device in the charging and discharging circuit. on , shutdown time T off And the maximum amplitude of the inductor current during the conduction period I L and I L The corresponding terminal voltage U across the capacitor C L The values ​​of the four variables.

[0103] Step S03: determining an optimal start-up time according to the on-time and off-time of the power electronic device.

[0104] In the present invention, the method for determining the optimal startup time according to the on-time and off-time of the power electronic device includes: determining the optimal startup time according to an optimal startup time calculation formula; wherein the optimal startup time calculation formula is:

[0105] T start =T on +T off (12);

[0106] Where: T start is the optimal start-up time, T on is the conduction time, T off is the shutdown duration;

[0107] And / or, the charging and discharging circuit is a Buck circuit.

[0108] In the embodiment of the present invention, the conduction duration T calculated according to step S02 on and the turn-off duration T off , and the total startup time, that is, the optimal startup time T, is calculated using formula (12). start .

[0109] Step S04: Analyze the optimal startup time, the conduction duration of the power electronic device, the turn-off duration, and the maximum amplitude of the inductor current during the conduction period to determine the output dynamic performance of the energy storage system charging and discharging circuit.

[0110] In the embodiment of the present invention, according to the obtained inductor current rise time (power electronic device conduction time) T on , the inductor current fall time (power electronic device turn-off time) T off , the optimal startup time (i.e., the total startup time) T start and the maximum current amplitude I L reached by the inductor current during startup, analyze and evaluate the dynamic performance of the energy storage system charging and discharging circuit (buck circuit), that is, judge whether the values of T on , T off , T start and I L are within the predetermined requirement range. If the predetermined requirements are met, it indicates that the charging output dynamic performance of the buck circuit is good.

[0111] It can be understood that the above-mentioned various method embodiments mentioned in the present invention can be combined with each other to form a combined embodiment without violating the principle logic. Due to space limitations, the present invention will not elaborate further.

[0112] The execution subject of the analysis method for the output dynamic performance of the energy storage system charging and discharging circuit can be an analysis device for the output dynamic performance of the energy storage system charging and discharging circuit. For example, the analysis method for the output dynamic performance of the energy storage system charging and discharging circuit can be executed by a terminal device or a server or other processing devices. Among them, the terminal device can be a user equipment (UE), a mobile device, a user terminal, a terminal, a cellular phone, a cordless phone, a personal digital assistant (PDA), a handheld device, a computing device, a vehicle-mounted device, a wearable device, etc. In some possible implementation manners, the analysis method for the output dynamic performance of the energy storage system charging and discharging circuit can be implemented by a processor invoking computer-readable instructions stored in a memory.

[0113] Those skilled in the art can understand that in the above methods of the specific embodiments, the writing order of each step does not mean a strict execution order and does not impose any limitation on the implementation process. The specific execution order of each step should be determined according to its function and possible internal logic.

[0114] The present invention also provides an analysis device for the output dynamic performance of a charge-discharge circuit of an energy storage system, including: an acquisition unit for acquiring the input voltage, inductance value, capacitance value, output voltage, and output power of the charge-discharge circuit; an operation unit for determining the conduction duration, turn-off duration of the power electronic device in the charge-discharge circuit, and the maximum amplitude of the inductor current during the conduction period according to the input voltage, inductance value, capacitance value, output voltage, and output power; an analysis unit for determining the optimal start time according to the conduction duration and turn-off duration of the power electronic device; and analyzing the optimal start time, the conduction duration, turn-off duration of the power electronic device, and the maximum amplitude of the inductor current during the conduction period to determine the output dynamic performance of the charge-discharge circuit of the energy storage system.

[0115] In an embodiment of the present invention, the acquisition unit includes an input electric energy calculation module 1, an inductance energy calculation module 2, a capacitance energy calculation module 3, and an output electric energy calculation module 4; the operation unit includes a solution module 5; and the analysis unit includes a display module 6.

[0116] Among them, the input voltage signal U of the externally provided buck circuit in is connected to the corresponding input terminal of the input electric energy calculation module 1, and the output of the input electric energy calculation module 1 is connected to the corresponding input terminal of the solution module 5; the externally provided buck circuit inductance value signal L, output voltage signal U o , output power signal P o are respectively connected to the corresponding input terminals of the inductance energy calculation module 2, and the output of the inductance energy calculation module 2 is connected to the corresponding input terminal of the solution module 5; the externally provided buck circuit capacitance value signal C, output voltage signal U o , output power signal P o are respectively connected to the corresponding input terminals of the capacitance energy calculation module 3, and the output of the capacitance energy calculation module 3 is connected to the corresponding input terminal of the solution module 5; the externally provided buck circuit output voltage signal U o , output power signal P o are respectively connected to the corresponding input terminals of the output electric energy calculation module 4, and the output of the output electric energy calculation module 4 is connected to the corresponding input terminal of the solution module 5; the output of the solution module 5 is connected to the corresponding input terminal of the display module 6.

[0117] The existing analysis of the startup process of the buck circuit shows that its optimal startup process only requires two changes: the initial monotonic increase of the inductor current (during which the power electronic device is always on) and the subsequent monotonic decrease of the inductor current (during which the power electronic device is always off) to reach the desired stable state. Based on this theoretical analysis, the present invention calculates the inductor current rise time, the maximum amplitude that the inductor current can reach, the inductor current fall time, and the optimal startup time during the optimal startup process, and displays the calculation results. The specific process is as follows:

[0118] First, input the determined input voltage signal U of the buck circuit in to the corresponding input terminal of the input electrical energy calculation module 1; input the determined inductor value signal L, output voltage signal U o , and output power signal P o to the corresponding input terminals of the inductor energy calculation module 2 respectively; input the determined capacitor value signal C, output voltage signal U o , and output power signal P o to the corresponding input terminals of the capacitor energy calculation module 3 respectively; input the determined output voltage signal U o and output power signal P o to the corresponding input terminals of the output electrical energy calculation module 4 simultaneously.

[0119] Second, the input electrical energy calculation module 1 uses formula (1) to form the calculation formula for the input electrical energy E in of the buck circuit during the conduction period of the power electronic device, and transmits the expression of formula (1) to the corresponding input terminal of the solution module 5; the inductor energy calculation module 2, according to the energy storage calculation principle of the inductor, uses formula (2) to form the calculation formula for the change in inductor energy storage E Lon of the buck circuit during the conduction period of the power electronic device, and at the same time uses formula (3) to form the calculation formula for the change in inductor energy storage E Loff of the buck circuit during the off period after the power electronic device changes from conduction to off, and transmits the expressions of formula (2) and formula (3) to the corresponding input terminal of the solution module 5; the capacitor energy calculation module 3, according to the energy storage calculation principle of the capacitor, uses formula (4) to form the calculation formula for the change in capacitor energy storage E Con of the buck circuit during the conduction period of the power electronic device, uses formula (5) to form the calculation formula for the change in capacitor energy storage E Coff of the buck circuit during the off period after the power electronic device changes from conduction to off, and forms the conduction time length T onThe calculation formula of the buck circuit power electronic device off time length T is formed by using formula (7) off The calculation formula of formula (4), (5), (6) and (7) is transmitted to the corresponding input terminal of the solution module 5; the output power calculation module 4 uses formula (8) to form a buck circuit to output energy E during the conduction period of the power electronic device. Oon The calculation formula of the buck circuit is formed by using formula (9). After the power electronic device changes from on to off, the output energy E in the off time period is Ooff The calculation formula of formula (8) and formula (9) are transmitted to the corresponding input terminal of the solution module 5.

[0120] Then, the solution module 5 obtains formula (10) according to the energy conservation principle of the buck circuit in the on-time period of the power electronic device according to the received 9 formula expressions, and obtains formula (11) according to the energy conservation principle of the buck circuit in the off-time period of the power electronic device; formulas (1) to (11) are combined to form an equation group to solve T on 、T off ,I L , U L A total of 4 variables are calculated. on 、T off ,I L The value is transmitted to the corresponding input terminal of the display module 6.

[0121] Finally, the display module 6 calculates the optimal start time according to the received data using formula (12): Tstart , and use the display device to display the inductor current rise time T on , Inductor current fall time T off , optimal start time T start and the maximum current amplitude I reached by the inductor current during the startup process L .

[0122] Among them, the input power calculation module 1, the inductance energy calculation module 2, the capacitance energy calculation module 3, the output power calculation module 4 and the solution module 5 can be composed of various chips or integrated circuits with functions such as receiving data, data calculation, and sending data, for example, they can be implemented by a single-chip microcomputer or a digital signal processor; the display module 6 can be composed of various chips or integrated circuits with functions such as receiving data, data calculation, and data display, for example, it can be implemented by combining a single-chip microcomputer with a liquid crystal display or a digital signal processor with a liquid crystal display.

[0123] In summary, the present invention is directed to the case where a buck circuit is used as a charging or discharging circuit and a known buck circuit input voltage signal Uin Inductance value signal L, capacitance value signal C, output voltage signal U o Output power signal P o Under the premise of their magnitudes, the inductance current rise time T during the optimal startup process of the charge-discharge circuit can be calculated on Inductance current fall time T off Optimal startup time T start And the maximum current amplitude I reached by the inductance current during the startup process L , thereby achieving an accurate analysis of the output dynamic performance of the charge-discharge circuit

[0124] In some embodiments, the functions, units, or modules included in the device provided by the embodiments of the present invention can be used to execute the methods described in the above method embodiments. The specific implementation can refer to the description of the above method embodiments. For the sake of brevity, it will not be elaborated here

[0125] Based on the known or designed basic parameters of the charge-discharge circuit, namely the circuit input voltage U in Circuit inductance value L, circuit capacitance value C, output voltage U o Output power P o , the inductance current rise time T during the optimal startup process can be directly obtained without using methods such as simulation on Inductance current fall time T off Optimal startup time T start And the maximum current amplitude I reached by the inductance current during the startup process L , greatly simplifying the performance analysis process of the charge-discharge circuit. Using the obtained inductance current rise time T during the optimal startup process on Inductance current fall time T off Optimal startup time T start And the maximum current amplitude I reached by the inductance current during the startup process L , the control effects of various charge-discharge circuit control strategies can be evaluated, greatly simplifying the performance evaluation process

[0126] The above have described the embodiments of the present invention. The above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations are obvious to those of ordinary skill in the art in the technical field without departing from the scope and spirit of the described embodiments. The selection of the terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other ordinary skill in the art in the technical field to understand the disclosed embodiments

Claims

1. A method for analyzing the output dynamic performance of a charge-discharge circuit of an energy storage system, characterized in that, Including: Obtain the input voltage, inductance value, capacitance value, output voltage, and output power of the charge and discharge circuit; Determine the conduction duration, turn-off duration of the power electronic device in the charge and discharge circuit, and the maximum amplitude of the inductor current during the conduction period according to the input voltage, inductance value, capacitance value, output voltage, and output power; Determine the optimal start time according to the conduction duration and turn-off duration of the power electronic device; Analyze the optimal start time, conduction duration, turn-off duration of the power electronic device, and the maximum amplitude of the inductor current during the conduction period to determine the output dynamic performance of the energy storage system charge and discharge circuit.

2. The method for analyzing the output dynamic performance of a charge-discharge circuit of an energy storage system according to claim 1, characterized in that, The method for determining the conduction duration, turn-off duration of the power electronic device in the charge and discharge circuit, and the maximum amplitude of the inductor current during the conduction period according to the input voltage, inductance value, capacitance value, output voltage, and output power includes: Obtain the relevant parameter formulas of the power electronic device in the charge and discharge circuit during the conduction period, including at least: input electrical energy, change in inductor energy storage, change in capacitor energy storage, conduction duration, and output energy calculation formulas, and the relevant parameter formulas during the turn-off period, including at least: change in inductor energy storage, change in capacitor energy storage, turn-off duration, and output energy calculation formulas; Determine the first relationship between the input electrical energy, change in inductor energy storage, change in capacitor energy storage, and output energy during the conduction period, and the second relationship between the change in inductor energy storage, change in capacitor energy storage, and output energy during the turn-off period; Determine the conduction duration, turn-off duration of the power electronic device in the charge and discharge circuit, and the maximum amplitude of the inductor current during the conduction period according to the first relationship, the second relationship, the relevant parameter formulas during the conduction period, and the relevant parameter formulas during the turn-off period.

3. The method for analyzing the output dynamic performance of a charge-discharge circuit of an energy storage system according to claim 2, characterized in that, The calculation formula for the change in inductor energy storage during the turn-off period is: Where: E Loff is the change in inductor energy storage during the turn-off period, L is the inductance value, P o is the output power, U o is the output voltage, I L is the maximum amplitude of the inductor current during the turn-on period.

4. The method for analyzing the output dynamic performance of a charge-discharge circuit of an energy storage system according to claim 2, characterized in that, The calculation formula for the conduction duration is: Where: T on is the conduction duration, C is the capacitance value, I L is the maximum amplitude of the inductor current during the conduction period, U L is the terminal voltage across the capacitor C corresponding to I L , P o is the output power, U o is the output voltage.

5. The method for analyzing the output dynamic performance of a charge-discharge circuit of an energy storage system according to claim 2, characterized in that, The calculation formula for the turn-off duration is: Where: T off is the turn-off duration, C is the capacitance value, I L is the maximum amplitude of the inductor current during the conduction period, U L is the terminal voltage across the capacitor C corresponding to I L , P o is the output power, U o is the output voltage.

6. The method for analyzing the output dynamic performance of a charge-discharge circuit of an energy storage system according to claim 2, characterized in that, The output energy during the conduction period is: Where: E Oon is the output energy during the conduction period, U L is the terminal voltage across the capacitor C corresponding to the maximum amplitude I L of the inductor current during the conduction period, P o is the output power, U o is the output voltage, T on is the conduction duration.

7. The method for analyzing the output dynamic performance of a charge-discharge circuit of an energy storage system according to claim 2, characterized in that, The output energy during the turn-off period is: Where: E Ooff is the output energy during the turn-off period, U L is the terminal voltage across the capacitor C corresponding to the maximum amplitude I L of the inductor current during the turn-on period, P o is the output power, U o is the output voltage, T off is the turn-off duration.

8. The method for analyzing the output dynamic performance of a charge-discharge circuit of an energy storage system according to claim 2, characterized in that, The first relationship is: E in = E Lon + E Con + E Oon ; Where: E in is the input electric energy during the conduction period, E Lon is the change in inductor energy storage during the conduction period, E Con is the change in capacitor energy storage during the conduction period, E Oon is the output energy during the conduction period; The second relationship is: 0 = E Loff + E Coff + E Ooff ; Where: E Loff is the change in inductor energy storage during the turn-off period, E Coff is the change in capacitor energy storage during the turn-off period, E Ooff is the output energy during the turn-off period.

9. The analysis method for the output dynamic performance of the charge and discharge circuit of the energy storage system according to any one of claims 1-8, characterized in that, The method for determining the optimal start time according to the conduction duration and turn-off duration of the power electronic device includes: Determine the optimal start time according to the optimal start time calculation formula; Wherein, the optimal start time calculation formula is: T start = T on + T off ; Where: T start is the optimal startup time, T on is the conduction duration, T off is the turn-off duration; And / or, the charge and discharge circuit is: Buck circuit.

10. An analysis device for the output dynamic performance of the charge and discharge circuit of the energy storage system, characterized in that, Including: An acquisition unit for obtaining the input voltage, inductance value, capacitance value, output voltage, and output power of the charge and discharge circuit; An operation unit for determining the conduction duration, turn-off duration of the power electronic device in the charge and discharge circuit, and the maximum amplitude of the inductor current during the conduction period according to the input voltage, inductance value, capacitance value, output voltage, and output power; An analysis unit for determining the optimal start time according to the conduction duration and turn-off duration of the power electronic device; analyzing the optimal start time, conduction duration, turn-off duration of the power electronic device, and the maximum amplitude of the inductor current during the conduction period to determine the output dynamic performance of the energy storage system charge and discharge circuit.

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