Energy storage processing method, device, electronic equipment and storage medium

Abstract

This invention discloses an energy storage processing method, apparatus, electronic device, and storage medium. The method includes: acquiring the grid output voltage; calculating the grid output reference power based on the grid output voltage error between the grid output voltage and the grid output reference voltage; calculating the grid reference current and DC link inductor reference current based on the grid output reference power, grid voltage amplitude, and grid voltage angle; calculating an adjustment variable based on the grid power error between the grid output reference power and the actual grid power; calculating an initial duty cycle; calculating the switching life loss error between the lifetime losses of each of the switching devices; processing the initial duty cycle based on the switching life loss error corresponding to the switching device to obtain the control duty cycle corresponding to the switching device; and controlling the switching of the switching device according to the control duty cycle corresponding to the switching device. Embodiments of this invention can improve the reliability of energy storage systems.

Description

Technical Field

[0001] The present invention relates to the field of energy storage, and in particular to an energy storage processing method, device, electronic equipment and storage medium. Background Art

[0002] Energy storage converters are essential equipment for new energy systems. The topology of the rectifier cascade DC converter enables it to have a wider range of output voltages, which can meet the needs of various different loads in charging electric new energy vehicles.

[0003] Generally, the energy storage converter is divided into a front-stage rectifier side and a rear-stage DC side. Both the front-stage circuit and the rear-stage circuit include switching devices.

[0004] There are differences in the parameters of the switching devices in the actual parallel structure. In the case of multi-phase current sharing, the heating damage of the switching devices will be uneven. The switching device in one phase will be damaged, while the switching device in another phase will cause the entire system to malfunction. Summary of the invention

[0005] The present invention provides an energy storage processing method, device, electronic equipment and storage medium, which can improve the reliability of the energy storage system.

[0006] According to one aspect of the present invention, there is provided an energy storage processing method, comprising:

[0007] Get the grid output voltage;

[0008] Calculating a grid output reference power according to a grid output voltage error between the grid output voltage and a grid output reference voltage;

[0009] Calculating a grid reference current and a DC link inductance reference current according to the grid output reference power, the grid voltage amplitude and the grid voltage angle;

[0010] Calculating a regulating variable according to a grid power error between the grid output reference power and the grid actual power;

[0011] Calculating an initial duty cycle according to the grid reference current, the DC link inductor reference current, a regulating variable, the grid voltage amplitude and the grid output reference voltage;

[0012] Calculating a switch life loss error between life losses of each of the switch devices;

[0013] The initial duty cycle is processed according to the switch life loss error corresponding to the switch device to obtain the control duty cycle corresponding to the switch device, and the switch of the switch device is controlled according to the control duty cycle corresponding to the switch device.

[0014] According to another aspect of the present invention, there is provided an energy storage processing device, characterized in that it comprises:

[0015] A power grid output voltage acquisition module, used to acquire the power grid output voltage;

[0016] A grid output reference power calculation module, used to calculate the grid output reference power according to the grid output voltage error between the grid output voltage and the grid output reference voltage;

[0017] A reference current determination module, used to calculate a grid reference current and a DC link inductance reference current according to the grid output reference power, the grid voltage amplitude and the grid voltage angle;

[0018] A regulating variable determination module, used for calculating a regulating variable according to a grid power error between the grid output reference power and the grid actual power;

[0019] An initial duty cycle determination module, configured to calculate an initial duty cycle according to the grid reference current, the DC link inductor reference current, a regulating variable, the grid voltage amplitude and the grid output reference voltage;

[0020] A life loss error determination module, used to calculate the switch life loss error between the life losses of each of the switch devices;

[0021] The first duty cycle compensation module is used to process the initial duty cycle according to the switch life loss error corresponding to the switch device, obtain the control duty cycle corresponding to the switch device, and control the switch of the switch device according to the control duty cycle corresponding to the switch device.

[0022] According to another aspect of the present invention, an electronic device is provided, the electronic device comprising:

[0023] at least one processor; and

[0024] a memory communicatively connected to the at least one processor; wherein,

[0025] The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the energy storage processing method described in any embodiment of the present invention.

[0026] According to another aspect of the present invention, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to implement the energy storage processing method described in any embodiment of the present invention when executed.

[0027] The technical solution of the embodiment of the present invention compensates for the calculated initial duty cycle according to the difference between the life losses of the switching devices, reasonably adjusts the duty cycle of the switching devices of each phase, and takes zero difference in the life damage of the switching devices of each phase as the goal, so that the switching devices can heat evenly, improve the reliability of the converter, and enable the converter to operate for a longer time. It can solve the technical problem that one phase is damaged due to thermal damage while the other phase still has a high life, thereby improving the reliability of the energy storage converter.

[0028] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0030] Figure 1 is a flow chart of an energy storage processing method provided according to an embodiment of the present invention;

[0031] Figure 2 is a flow chart of an energy storage processing method provided according to an embodiment of the present invention;

[0032] Figure 3 is a scene diagram of an energy storage processing method provided according to an embodiment of the present invention;

[0033] Figure 4 is a schematic diagram of a method for generating a regulating variable of a bridge arm output voltage provided in accordance with an embodiment of the present invention;

[0034] Figure 5 is a schematic diagram of a method for generating a DC link inductor reference current according to an embodiment of the present invention;

[0035] Figure 6 A schematic diagram of a method for generating an initial duty cycle according to an embodiment of the present invention;

[0036] Figure 7 A schematic diagram of a first duty cycle compensation value generation method with zero difference in life loss as the goal provided by an embodiment of the present invention;

[0037] Figure 8 A schematic diagram of a second duty cycle compensation value generation method with zero output voltage static error as the goal provided by an embodiment of the present invention;

[0038] Fig. 9 is a structural schematic diagram of an energy storage processing device provided according to an embodiment of the present invention;

[0039] Fig.10 It is a structural schematic diagram of an electronic device for implementing the energy storage processing method of an embodiment of the present invention. DETAILED DESCRIPTION

[0040] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0041] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0042] Embodiment 1

[0043] Figure 1 A flow chart of an energy storage processing method provided in Embodiment 1 of the present invention. The embodiment of the present invention can be applied to the switch control of an energy storage converter, the method can be executed by an energy storage processing device, the energy storage processing device can be implemented in the form of hardware and / or software, the energy storage processing device can be configured in an electronic device with a certain data computing capability, and the electronic device can be a server.

[0044] The energy storage processing method of the embodiment of the present invention is applied to an energy storage converter system, wherein the energy storage converter includes a rectifier-side converter and a DC-side converter; the DC-side converter includes a plurality of switch devices. The DC-side converter adopts a Boost circuit, and the DC-side converter includes an insulated gate bipolar transistor (IGBT) (S7-S8) and a diode (D1-D2); the rectifier-side converter adopts a three-phase six-switch (S1-S6) reverse resistance topology. The energy storage converter may also include a DC-side output capacitor C dc , grid-side filter LC and DC link inductor currents L1 and L2.

[0045] The embodiment of the present invention can be executed by a digital signal processor (Digital Signal Processing, DSP), and the control signal is sent to a field-programmable gate array (Field-Programmable Gate Array, FPGA). The FPGA generates a pulse signal to control the switch device to turn on and off.

[0046] See also Figure 1 The energy storage processing method shown comprises:

[0047] S101. Obtaining a power grid output voltage.

[0048] The AC power of the AC grid is input into the energy storage converter system, and the output voltage outputted from the output end of the energy storage converter is used as the grid output voltage, which can be collected and obtained. The grid output voltage is used for feedback closed-loop control.

[0049] S102: Calculate a grid output reference power according to a grid output voltage error between the grid output voltage and a grid output reference voltage.

[0050] The grid output reference voltage may refer to an output voltage command value. The grid output voltage error may refer to the difference between the grid output voltage and the grid output reference voltage. The grid output reference power is calculated by the output voltage control loop PI (Proportion Integration, proportional integral controller).

[0051] S103: Calculate a grid reference current and a DC link inductance reference current according to the grid output reference power, the grid voltage amplitude, and the grid voltage angle.

[0052] The grid reference current can be calculated based on the instantaneous power method.

[0053] Optionally, calculating the DC link inductance reference current according to the grid output reference power, the grid voltage amplitude and the grid voltage angle includes: calculating the grid reference current according to the grid output reference power and the grid voltage amplitude; calculating the DC link inductance reference current according to the grid reference current and the grid voltage angle.

[0054] The quotient of the grid output reference power and 1.5 times the grid voltage amplitude is determined as the grid reference current. d_ref =P g_ref / (1.5*V d ). Among them, P g_ref is the grid output reference power, V d is the grid voltage amplitude.

[0055] Optionally, calculating the DC link inductance reference current according to the grid reference current and the grid voltage angle includes: calculating the three-phase reference current according to the grid reference current and the grid voltage angle; obtaining the absolute value of the reference current of each phase; obtaining the maximum value of the absolute value of the reference current of each phase, and determining it as the DC link inductance reference current.

[0056] The grid voltage angle θ can be obtained by processing the sampling result of the three-phase voltage of the AC power according to a phase locked loop (PLL).

[0057] Multiply the grid reference current by the grid voltage angle to obtain the three-phase reference current, for example, i a_ref , i b_ref ,i c-ref Obtain the absolute values ​​of the three-phase reference currents. And take the maximum values ​​of the absolute values ​​of the three-phase reference currents in turn as the DC link inductance reference current.

[0058] S104: Calculate a regulating variable according to a grid power error between the grid output reference power and the grid actual power.

[0059] The grid output reference power may refer to the output power command value. The grid output power error may refer to the difference between the grid actual power and the grid output reference power. The adjustment variable is calculated by the output voltage control loop PI (Proportion Integration, proportional integral controller). The adjustment variable is used to generate the corresponding control signal, which is finally fed back to the grid actual power to make the grid actual power close to the grid output reference power.

[0060] The actual power of the power grid refers to the actual power output of the AC power grid, which can be calculated based on the grid voltage amplitude and grid current amplitude. g =i d*1.5*V d .

[0061] S105 , calculating an initial duty cycle according to the grid reference current, the DC link inductor reference current, the adjustment variable, the grid voltage amplitude and the grid output reference voltage.

[0062] The initial duty cycle can be calculated using the duty cycle formula of the Boost circuit.

[0063] S106, calculating the switch life loss error between the life losses of the switch components.

[0064] The difference between the life losses of the two switching devices is used as the switch life loss error of the two switching devices. In the embodiment of the present invention, modulation is performed with the goal of making the life loss error of the two switching devices zero.

[0065] S107 . Process the initial duty cycle according to the switch life loss error corresponding to the switch device to obtain a control duty cycle corresponding to the switch device, and control the switch device to switch according to the control duty cycle corresponding to the switch device.

[0066] According to the switch life loss error, the compensation value of the duty cycle is determined, and the compensation value is added to the initial duty cycle to obtain the control duty cycle. The control duty cycle corresponding to the switching device can be sent to the signal generator to generate a signal corresponding to the control duty cycle, which is sent to the corresponding switching device so that the corresponding switching device performs corresponding switch control to balance the life loss of each switch. The control duty cycle corresponding to the switching device controls the switching device so that the duty cycle of the phase circuit with higher life damage is lower, so that a lower current flows through it and its life is extended; and the duty cycle of the phase circuit with lower life damage is higher, so that it bears more thermal stress.

[0067] The technical solution of the embodiment of the present invention compensates for the calculated initial duty cycle according to the difference between the life losses of the switching devices, reasonably adjusts the duty cycle of the switching devices of each phase, and takes zero difference in the life damage of the switching devices of each phase as the goal, so that the switching devices can heat evenly, improve the reliability of the converter, and enable the converter to operate for a longer time. It can solve the technical problem that one phase is damaged due to thermal damage while the other phase still has a high life, thereby improving the reliability of the energy storage converter.

[0068] Embodiment 2

[0069] Figure 2A flow chart of an energy storage processing method provided for the second embodiment of the present invention. Based on the above embodiments, the embodiment of the present invention concretizes "processing the initial duty cycle according to the switch life loss error corresponding to the switch device to obtain the control duty cycle corresponding to the switch device" as "calculating a first duty cycle compensation value according to the switch life loss error corresponding to the switch device; adjusting the duty cycle compensation value according to the sign of the switch life loss error corresponding to the switch device to obtain an adjusted first duty cycle compensation value; superimposing the adjusted first duty cycle compensation value with the initial duty cycle to obtain the control duty cycle corresponding to the switch device". It should be noted that for the parts not described in detail in the embodiments of the present invention, reference may be made to the descriptions of other embodiments.

[0070] See also Figure 2 The energy storage processing method shown comprises:

[0071] S201. Obtain the grid output voltage.

[0072] S202: Calculate a grid output reference power according to a grid output voltage error between the grid output voltage and a grid output reference voltage.

[0073] S203: Calculate a grid reference current and a DC link inductance reference current according to the grid output reference power, the grid voltage amplitude, and the grid voltage angle.

[0074] S204: Calculate a regulating variable according to a grid power error between the grid output reference power and the grid actual power.

[0075] S205 . Calculate an initial duty cycle according to the grid reference current, the DC link inductor reference current, the adjustment variable, the grid voltage amplitude, and the grid output reference voltage.

[0076] Optionally, the initial duty cycle is calculated according to the grid reference current, the DC link inductor reference current, the regulating variable, the grid voltage amplitude and the grid output reference voltage, including: calculating the average value of the bridge arm output voltage according to the grid reference current, the DC link inductor reference current and the grid voltage amplitude; adjusting the average value of the bridge arm output voltage according to the regulating variable to obtain an equivalent bridge arm output voltage; and calculating the initial duty cycle according to the grid output reference voltage, the equivalent bridge arm output voltage and the regulating variable.

[0077] Calculate the DC link inductor reference current I link_ref With the grid reference current i d_ref The quotient of 1.5*V is the fluctuation component. d Divide by this fluctuation component to get the average output voltage V of the bridge armpn_avg .

[0078] The calculated average bridge arm output voltage V pn_avg It is higher than the actual value, so it is necessary to adjust the average value of the bridge arm output voltage V by adjusting the variable. pn_avg , and then calculate the equivalent bridge arm output voltage V pn_eq For example, to calculate the average bridge arm output voltage V pn_avg The sum of the adjusted variable δ gives the equivalent bridge arm output voltage V pn_eq .

[0079] Based on the following formula, calculate the grid output reference voltage V o The equivalent bridge arm output voltage V pn_eq The difference between the grid output reference voltage V o The ratio of is determined as the initial duty cycle D.

[0080] D=(V o -V pn_eq ) / V o

[0081] S206, calculating a switch life loss error between the life losses of the switch components.

[0082] For each switching device, the difference between the life losses of each two switching devices is calculated as the switch life loss error between the two switching devices. Exemplarily, the number of switching devices is two. The difference between the life losses of the two switching devices is calculated and determined as the switch life loss error between the two switching devices.

[0083] In a specific example, the switch devices include S7 and S8. The switch life loss error between the two switch devices is CL S7 -CL S8 .

[0084] S207: Calculate a first duty cycle compensation value according to a switch life loss error corresponding to the switch device.

[0085] For each switching device, the switch life loss error corresponding to the switching device is obtained, and the difference between the switch life loss error corresponding to the switching device and 0 is calculated, such as 0-(CL S7 -CL S8 ), the difference is input into PI processing to obtain a first duty cycle compensation value ΔD. That is, the switch life loss error corresponding to the switching device is input into PI processing to obtain a first duty cycle compensation value.

[0086] S208 . Adjust the duty cycle compensation value according to the sign of the switch life loss error corresponding to the switch device to obtain an adjusted first duty cycle compensation value.

[0087] The sign of the duty cycle compensation value is determined according to the subtrahend and the minuend in the switch life loss error calculation formula corresponding to the switch device. For example, the sign of the duty cycle compensation value of the minuend switch device is negative; the sign of the duty cycle compensation value of the subtrahend switch device is positive. The sign of the duty cycle compensation value is added to the duty cycle compensation value to obtain a first duty cycle compensation value.

[0088] For example, the switch life loss error is CL S7 -CL S8 For the switching device S7, the sign of the duty cycle compensation value is negative; for the switching device S8, the sign of the duty cycle compensation value is positive.

[0089] S209: Superimpose the adjusted first duty cycle compensation value with the initial duty cycle to obtain a control duty cycle corresponding to the switching device, and control the switching of the switching device according to the control duty cycle corresponding to the switching device.

[0090] The sum of the first duty cycle compensation value and the initial duty cycle is determined as the control duty cycle corresponding to the switching device.

[0091] In addition, in fact, the switch devices in the front-stage rectifier-side converter also need to be adjusted. The DC link inductor reference current can be used as the amplitude of the high-frequency carrier of the front-stage rectifier-side converter circuit, and the product of the grid voltage angle and the DC link inductor reference current can be used as the three-phase current modulation wave of the front-stage rectifier-side converter.

[0092] Optionally, after obtaining the control duty cycle corresponding to the switching device, it also includes: calculating a second duty cycle compensation value based on a DC link inductor current error between the actual DC link inductor current and the DC link inductor reference current; processing the second duty cycle compensation value based on the life loss ratio of the switching device to obtain a processed second duty cycle compensation value; and updating the control duty cycle based on the processed second duty cycle compensation value.

[0093] The actual current of the DC link inductor can be obtained by collecting the current at the inductor of the energy storage converter system. In order to avoid the static error of the output voltage after adding the duty cycle compensation value, it is necessary to output the DC link inductor reference current I through the bridge arm. link_ref The actual current I of the DC link inductor output by the bridge arm linkThe error value is processed by PI to obtain the second duty cycle compensation value for preventing static error. Because the case where the life damage value is equal is multiple operating points, it is necessary to constrain the duty cycle compensation value through the DC link inductance reference current to become a single operating point.

[0094] The difference between the actual current of the DC link inductor and the reference current of the DC link inductor is used to determine the DC link inductor current error. The DC link inductor current error is input into the PI to obtain the second duty cycle compensation value. For example, for the switching devices S7 and S8, the second duty cycle compensation values ​​are respectively x S7 and χ S8 The life loss ratio between the switching devices is calculated, the second ratio compensation value is processed to obtain a processed second duty cycle compensation value, and the processed second duty cycle compensation value is added to the control duty cycle to update the control duty cycle. Specifically, the adjusted first duty cycle compensation value and the processed second duty cycle compensation value are accumulated in the initial duty cycle to obtain the final control duty cycle.

[0095] By using the DC link inductor current reference value as a constraint condition, the actual DC link inductor current I link Reach the DC link inductor reference current I link_ref , the output of the PI controller can be used as another set of duty cycle compensation variables. The calculated duty cycle needs to be allocated according to the life loss of the two high-frequency switches. For the switch devices S7 and S8, the allocation is performed according to the following formula:

[0096] y S7 =CL S8 / (CL S7 +CL S8 )*χ S7

[0097] y S8 =CL S7 / (CL S7 +CL S8 )*χ S8

[0098] y S7 is the second ratio compensation value after processing corresponding to the switch device S7, y S8 is the second proportion compensation value after corresponding processing of the switching device S8.

[0099] By compensating the duty cycle to eliminate static errors, the loss life can be made uniform.

[0100] Optionally, calculating the regulating variable according to a grid power error between the grid output reference power and the grid actual power includes: filtering the grid power error; and calculating the regulating variable according to the filtered grid power error.

[0101] A low pass filter (LPF) can be used for filtering.

[0102] By filtering the grid power error, high-frequency ripple is filtered out to eliminate its influence on the generated regulating variable.

[0103] The embodiment of the present invention can make the high-frequency switch life loss in multiple branches in the DC side converter more uniform by using a high-reliability control strategy, thereby extending the life of the converter. Through a control loop based on zero-difference loss life and a proposed DC link inductor current loop for the purpose of eliminating static errors, the duty cycle of the DC side converter can be reasonably adjusted to achieve uniform loss life.

[0104] Embodiment 3

[0105] Figure 3 A scene diagram of an energy storage processing method provided in Example 3 of the present invention. Figure 4 A strategy for generating a regulation variable for the output voltage of the bridge arm in the embodiment. Figure 5 This is a DC link inductor current reference value generation strategy in an embodiment. Figure 6 1 is an algorithm block diagram of the improved active disturbance rejection controller UADRC3 in the embodiment. Figure 7 The present invention is a compensation duty cycle generation strategy for achieving “zero difference in life loss” of the high-frequency switch tubes (S7, S8) in the subsequent DC-side Boost in the embodiment. Figure 8 This is a strategy for generating a supplementary duty cycle of high-frequency switch tubes (S7, S8) in the subsequent DC-side Boost of the output voltage zero static error regulation in the embodiment.

[0106] Collect the three-phase voltage V of the power grid a 、V b 、V c and the three-phase current i a 、i b 、i c , based on the following formula, the grid voltage amplitude V is calculated by coordinate transformation d and the grid current amplitude i d .

[0107]

[0108]

[0109]

[0110]

[0111]

[0112] like Figure 4 As shown, by according to the grid output voltage V o and the grid output reference voltage V o_ref The error between them is calculated by the output voltage control loop PI to obtain the grid output reference power P g_ref , calculate the actual power of the power grid P g , grid output reference power P g_ref The actual power P g The error value P g_ref -P g After entering PI, the adjustment variable δ is calculated. Before entering PI, the error can be input into a low-pass filter LPF to filter out the ripple in the error, and then input into PI to generate a more stable adjustment variable.

[0113] like Figure 5 As shown, the grid output current d-axis active component i is calculated by instantaneous power method. d_ref The three-phase reference current i is formed by the grid voltage angle calculated by the phase-locked loop PLL. a_ref , i b_ref , i c-ref . Calculate the grid reference current i d_ref =P g_ref / (1.5*V d ), multiply the grid reference current by the grid voltage angle to obtain the three-phase reference current, for example, i a_ref , i b_ref , i c-ref . Obtain the absolute value of the three-phase reference current. And take the maximum value in the absolute value of the three-phase reference current in turn as the DC link inductance reference current Ilink_ref. The power calculation formula is as follows:

[0114] ;

[0115] in, , is the output after Clarke transformation.

[0116] like Figure 6 As shown, calculate the DC link inductor reference current I link_ref With the grid reference current i d_ref The quotient of 1.5*V is the fluctuation component. d Divide by this fluctuation component to get the average output voltage V of the bridge arm pn_avg However, considering the device voltage drop problem, the theoretically calculated average bridge arm output voltage V pn_avg It is higher than the actual value, so it is necessary to adjust the average value of the bridge arm output voltage V by adjusting the variable δ pn_avg, calculate the average bridge arm output voltage V pn_avg The sum of the adjusted variable δ gives the equivalent bridge arm output voltage V pn_eq . Calculate the grid output reference voltage V o_ref The equivalent bridge arm output voltage V pn_eq The difference between the grid output reference voltage V o_ref The ratio of is determined as the initial duty cycle D, which can neither achieve current equalization nor equal distribution of life damage.

[0117] like Figure 7 As shown, in order to make the high-frequency switch loss life of each branch of the staggered parallel DC side converter uniformly distributed, the life loss difference CL of the high-frequency switch in the two branches is calculated based on the life loss difference CL S7 -CL S8 As a feedback variable, "zero" is used as a life loss reference value to eliminate the life loss difference of the high-frequency switches in the two branches, and the first compensation duty cycle is calculated by the PI controller and added to the original duty cycle D.

[0118] The DC side converter includes two switching devices. By calculating the life damage of the switching device of the rear-stage DC side converter, the error between the two life damage values ​​is used as a reference value, and a first duty cycle compensation value is generated after passing through a PI controller.

[0119] In order to avoid static error in the output voltage after adding the duty cycle compensation value, it is necessary to output the DC link inductor reference current I through the bridge arm. link_ref The actual current I of the DC link inductor output by the bridge arm link The error value is processed by PI to obtain the second duty cycle compensation value χ to prevent static error. S7 and χ S8 Because the life damage value is equal to multiple operating points, it is necessary to use the DC link inductor reference current I link_ref Constrain the adjustment of the duty cycle compensation value to a single operating point.

[0120] The difference between the actual current of the DC link inductor and the reference current of the DC link inductor is used to determine the DC link inductor current error. The DC link inductor current error is input into the PI to obtain the second duty cycle compensation value. For example, for the switching devices S7 and S8, the second duty cycle compensation values ​​are respectively x S7 and χ S8 The life loss ratio between the switching devices is calculated, the second ratio compensation value is processed to obtain a processed second duty cycle compensation value, and the processed second duty cycle compensation value is added to the control duty cycle to update the control duty cycle. Specifically, the adjusted first duty cycle compensation value and the processed second duty cycle compensation value are accumulated in the initial duty cycle to obtain the final control duty cycle.

[0121] like Figure 8 As shown in FIG. 1 , by using the DC link inductor current reference value as a constraint condition, the actual DC link inductor current I output by the bridge arm is link Reach the DC link inductor reference current I link_ref , the output of the PI controller can be used as another set of duty cycle compensation variables. The calculated duty cycle needs to be allocated according to the life loss of the two high-frequency switches. For the switch devices S7 and S8, the allocation is performed according to the following formula:

[0122] y S7 =CL S8 / (CL S7 +CL S8 )*χ S7

[0123] y S8 =CL S7 / (CL S7 +CL S8 )*χ S8

[0124] y S7 is the second ratio compensation value after processing corresponding to the switch device S7, y S8 is the second proportion compensation value after corresponding processing of the switching device S8.

[0125] The technical solution of the embodiment of the present invention compensates the calculated initial duty cycle according to the difference between the life losses of the switching devices, reasonably adjusts the duty cycle of the switching devices of each phase, and takes the zero difference of the life damage of the switching devices of each phase as the goal, so that the switching devices are heated evenly, the reliability of the converter is improved, and the converter can be operated for a longer time. It can solve the technical problem that one phase is damaged due to thermal damage while the other phase still has a high life, improve the reliability of the energy storage converter, and by using a high-reliability control strategy, the life loss of high-frequency switches in multiple branches in the DC side converter can be more uniform, thereby extending the life of the converter. Through a control loop based on zero-difference loss life and a proposed DC link inductor current loop for the purpose of eliminating static errors, it is possible to reasonably adjust the duty cycle of the DC side converter to achieve uniform loss life.

[0126] Embodiment 4

[0127] Fig. 9 A schematic diagram of the structure of an energy storage processing device provided in Embodiment 4 of the present invention. The embodiment of the present invention can be applied to the switch control of an energy storage converter, the device can execute an energy storage processing method, the device can be implemented in the form of hardware and / or software, and the device can be configured in an electronic device that carries a function with a certain data computing capability.

[0128] See also Fig. 9 The energy storage processing device shown comprises:

[0129] A power grid output voltage acquisition module 301 is used to acquire the power grid output voltage;

[0130] A grid output reference power calculation module 302, configured to calculate a grid output reference power according to a grid output voltage error between the grid output voltage and the grid output reference voltage;

[0131] A reference current determination module 303, configured to calculate a grid reference current and a DC link inductance reference current according to the grid output reference power, the grid voltage amplitude and the grid voltage angle;

[0132] A regulating variable determining module 304 is used to calculate a regulating variable according to a grid power error between the grid output reference power and the grid actual power;

[0133] An initial duty cycle determination module 305 is used to calculate an initial duty cycle according to the grid reference current, the DC link inductor reference current, the adjustment variable, the grid voltage amplitude and the grid output reference voltage;

[0134] A life loss error determination module 306, configured to calculate a switch life loss error between life losses of the switch components;

[0135] The first duty cycle compensation module 307 is used to process the initial duty cycle according to the switch life loss error corresponding to the switch device, obtain the control duty cycle corresponding to the switch device, and control the switch of the switch device according to the control duty cycle corresponding to the switch device.

[0136] The technical solution of the embodiment of the present invention compensates for the calculated initial duty cycle according to the difference between the life losses of the switching devices, reasonably adjusts the duty cycle of the switching devices of each phase, and takes zero difference in the life damage of the switching devices of each phase as the goal, so that the switching devices can heat evenly, improve the reliability of the converter, and enable the converter to operate for a longer time. It can solve the technical problem that one phase is damaged due to thermal damage while the other phase still has a high life, thereby improving the reliability of the energy storage converter.

[0137] Furthermore, the first duty cycle compensation module is specifically used to: calculate a first duty cycle compensation value according to a switch life loss error corresponding to the switching device; adjust the duty cycle compensation value according to the sign of the switch life loss error corresponding to the switching device to obtain an adjusted first duty cycle compensation value; and superimpose the adjusted first duty cycle compensation value with the initial duty cycle to obtain a control duty cycle corresponding to the switching device.

[0138] Furthermore, the energy storage processing device also includes: a second duty cycle compensation module, which is used to calculate a second duty cycle compensation value according to a DC link inductor current error between an actual DC link inductor current and a DC link inductor reference current after obtaining the control duty cycle corresponding to the switching device; process the second duty cycle compensation value according to a life loss ratio of the switching device to obtain a processed second duty cycle compensation value; and update the control duty cycle according to the processed second duty cycle compensation value.

[0139] Furthermore, the reference current determination module is specifically used to: calculate a grid reference current according to the grid output reference power and the grid voltage amplitude; and calculate a DC link inductance reference current according to the grid reference current and the grid voltage angle.

[0140] Furthermore, the reference current determination module is specifically used to: calculate the three-phase reference current according to the grid reference current and the grid voltage angle; obtain the absolute value of the reference current of each phase; obtain the maximum value of the absolute value of the reference current of each phase, and determine it as the DC link inductance reference current.

[0141] Furthermore, the adjustment variable determination module is specifically used to: filter the power grid power error; and calculate the adjustment variable according to the filtered power grid power error.

[0142] Furthermore, the initial duty cycle determination module is specifically used to: calculate the average value of the bridge arm output voltage based on the grid reference current, the DC link inductance reference current and the grid voltage amplitude; adjust the average value of the bridge arm output voltage according to the adjustment variable to obtain the equivalent bridge arm output voltage; calculate the initial duty cycle based on the grid output reference voltage, the equivalent bridge arm output voltage and the adjustment variable.

[0143] The energy storage processing device provided in the embodiment of the present invention can execute the energy storage processing method provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the execution method.

[0144] In the technical solutions of the embodiments of the present invention, the acquisition, storage and application of network traffic etc. involved are in compliance with the provisions of relevant laws and regulations and do not violate public order and good morals.

[0145] Embodiment 5

[0146] Fig.10A schematic diagram of the structure of an electronic device 400 that can be used to implement an embodiment of the present invention is shown. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices (such as helmets, glasses, watches, etc.) and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present invention described and / or required herein.

[0147] like Fig.10 As shown, the electronic device 400 includes at least one processor 401, and a memory connected to the at least one processor 401 in communication, such as a read-only memory (ROM) 402, a random access memory (RAM) 403, etc., wherein the memory stores a computer program that can be executed by at least one processor, and the processor 401 can perform various appropriate actions and processes according to the computer program stored in the read-only memory (ROM) 402 or the computer program loaded from the storage unit 408 to the random access memory (RAM) 403. In the RAM 403, various programs and data required for the operation of the electronic device 400 can also be stored. The processor 401, the ROM 402, and the RAM 403 are connected to each other via a bus 404. An input / output (I / O) interface 405 is also connected to the bus 404.

[0148] Multiple components in the electronic device 400 are connected to the I / O interface 405, including: an input unit 406, such as a keyboard, a mouse, etc.; an output unit 407, such as various types of displays, speakers, etc.; a storage unit 408, such as a disk, an optical disk, etc.; and a communication unit 409, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 409 allows the electronic device 400 to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.

[0149] The processor 401 may be a variety of general and / or special processing components with processing and computing capabilities. Some examples of the processor 401 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any appropriate processor, controller, microcontroller, etc. The processor 401 performs the various methods and processes described above, such as the energy storage processing method.

[0150] In some embodiments, the energy storage processing method may be implemented as a computer program, which is tangibly contained in a computer-readable storage medium, such as a storage unit 408. In some embodiments, part or all of the computer program may be loaded and / or installed on the electronic device 400 via the ROM 402 and / or the communication unit 409. When the computer program is loaded into the RAM 403 and executed by the processor 401, one or more steps of the energy storage processing method described above may be performed. Alternatively, in other embodiments, the processor 401 may be configured to perform the energy storage processing method in any other appropriate manner (e.g., by means of firmware).

[0151] Various implementations of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chips (SOCs), complex programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various implementations can include: being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0152] Computer programs for implementing the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that when the computer program is executed by the processor, the functions / operations specified in the flow chart and / or block diagram are implemented. The computer program may be executed entirely on the machine, partially on the machine, partially on the machine and partially on a remote machine as a stand-alone software package, or entirely on a remote machine or server.

[0153] In the context of the present invention, a computer-readable storage medium may be a tangible medium that may contain or store a computer program for use by or in conjunction with an instruction execution system, device, or equipment. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or equipment, or any suitable combination of the foregoing. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. A more specific example of a machine-readable storage medium may include an electrical connection based on one or more lines, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0154] To provide interaction with a user, the systems and techniques described herein may be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and a pointing device (e.g., a mouse or trackball) through which the user can provide input to the electronic device. Other types of devices may also be used to provide interaction with the user; for example, the feedback provided to the user may be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user may be received in any form (including acoustic input, voice input, or tactile input).

[0155] The systems and techniques described herein may be implemented in a computing system that includes backend components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes frontend components (e.g., a user computer with a graphical user interface or a web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such backend components, middleware components, or frontend components. The components of the system may be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), a blockchain network, and the Internet.

[0156] A computing system may include a client and a server. The client and the server are generally remote from each other and usually interact through a communication network. The client and server relationship is generated by computer programs running on the corresponding computers and having a client-server relationship with each other. The server may be a cloud server, also known as a cloud computing server or cloud host, which is a host product in the cloud computing service system to solve the defects of difficult management and weak business scalability in traditional physical hosts and VPS (Virtual Private Server) services.

[0157] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0158] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An energy storage processing method, characterized in that: Applied to an energy storage converter system, the energy storage converter includes a rectifier-side converter and a DC-side converter; the DC-side converter includes a plurality of switch devices; the method includes: Get the grid output voltage; Calculating a grid output reference power according to a grid output voltage error between the grid output voltage and a grid output reference voltage; Calculating a grid reference current and a DC link inductance reference current according to the grid output reference power, the grid voltage amplitude and the grid voltage angle; Calculating a regulating variable according to a grid power error between the grid output reference power and the grid actual power; Calculating an initial duty cycle according to the grid reference current, the DC link inductor reference current, a regulating variable, the grid voltage amplitude and the grid output reference voltage; Calculating the switch life loss error between the life losses of the switching devices; for each switching device, calculating the difference between the life losses of every two switching devices as the switch life loss error between the two switching devices; Calculating a first duty cycle compensation value according to a switch life loss error corresponding to the switch device; obtaining a switch life loss error corresponding to each switch device, calculating a difference between the switch life loss error corresponding to the switch device and 0, and inputting the difference into PI processing to obtain a first duty cycle compensation value ΔD; According to the sign of the switch life loss error corresponding to the switching device, the duty cycle compensation value is adjusted to obtain an adjusted first duty cycle compensation value; according to the subtrahend and the minuend in the switch life loss error calculation formula corresponding to the switching device, the sign of the duty cycle compensation value of the minuend switching device is determined, the sign of the duty cycle compensation value of the minuend switching device is negative; the sign of the duty cycle compensation value of the subtrahend switching device is positive, and the sign of the duty cycle compensation value is added to the duty cycle compensation value to obtain the first duty cycle compensation value; The adjusted first duty cycle compensation value is superimposed on the initial duty cycle to obtain a control duty cycle corresponding to the switching device, and the switching of the switching device is controlled according to the control duty cycle corresponding to the switching device.

2. The method according to claim 1, characterized in that: The processing of the initial duty cycle according to the switch life loss error corresponding to the switch device to obtain the control duty cycle corresponding to the switch device includes: Calculating a first duty cycle compensation value according to a switch life loss error corresponding to the switch device; adjusting the duty cycle compensation value according to the sign of the switch life loss error corresponding to the switch device to obtain an adjusted first duty cycle compensation value; The adjusted first duty cycle compensation value is superimposed on the initial duty cycle to obtain a control duty cycle corresponding to the switching device.

3. The method according to claim 1, characterized in that After obtaining the control duty ratio corresponding to the switch device, the method further includes: Calculating a second duty cycle compensation value according to a DC link inductor current error between an actual DC link inductor current and the DC link inductor reference current; Processing the second duty cycle compensation value according to the life loss ratio of the switching device to obtain a processed second duty cycle compensation value; The control duty cycle is updated according to the processed second duty cycle compensation value.

4. The method according to claim 1, characterized in that: The calculating the DC link inductance reference current according to the grid output reference power, the grid voltage amplitude and the grid voltage angle comprises: Calculating a grid reference current according to the grid output reference power and the grid voltage amplitude; A DC link inductance reference current is calculated according to the grid reference current and the grid voltage angle.

5. The method according to claim 4, characterized in that The calculating the DC link inductance reference current according to the grid reference current and the grid voltage angle includes: Calculating a three-phase reference current according to the grid reference current and the grid voltage angle; Obtain the absolute value of each phase reference current; The maximum value among the absolute values ​​of the reference currents of the phases is obtained and determined as the DC link inductance reference current.

6. The method according to claim 1, characterized in that The calculating the adjustment variable according to the grid power error between the grid output reference power and the grid actual power comprises: filtering the grid power error; The manipulated variable is calculated based on the filtered grid power error.

7. The method according to claim 1, characterized in that The calculating the initial duty cycle according to the grid reference current, the DC link inductor reference current, the adjustment variable, the grid voltage amplitude and the grid output reference voltage includes: Calculating an average value of the bridge arm output voltage according to the grid reference current, the DC link inductor reference current and the grid voltage amplitude; The average value of the bridge arm output voltage is adjusted according to the adjustment variable to obtain an equivalent bridge arm output voltage; An initial duty cycle is calculated according to the grid output reference voltage, the equivalent bridge arm output voltage and the adjustment variable.

8. An energy storage processing device for use in the energy storage processing method according to any one of claims 1 to 7, characterized in that: include: A power grid output voltage acquisition module, used to acquire the power grid output voltage; A grid output reference power calculation module, used to calculate the grid output reference power according to the grid output voltage error between the grid output voltage and the grid output reference voltage; A reference current determination module, used to calculate a grid reference current and a DC link inductance reference current according to the grid output reference power, the grid voltage amplitude and the grid voltage angle; A regulating variable determination module, used for calculating a regulating variable according to a grid power error between the grid output reference power and the grid actual power; An initial duty cycle determination module, configured to calculate an initial duty cycle according to the grid reference current, the DC link inductor reference current, a regulating variable, the grid voltage amplitude and the grid output reference voltage; A life loss error determination module, used to calculate the switch life loss error between the life losses of each of the switch devices; The first duty cycle compensation module is used to process the initial duty cycle according to the switch life loss error corresponding to the switch device, obtain the control duty cycle corresponding to the switch device, and control the switch of the switch device according to the control duty cycle corresponding to the switch device, specifically: calculate the switch life loss error between the life losses of each of the switch devices; for each switch device, calculate the difference between the life losses of every two switch devices as the switch life loss error between the two switch devices; calculate the first duty cycle compensation value according to the switch life loss error corresponding to the switch device; for each switch device, obtain the switch life loss error corresponding to the switch device, calculate the difference between the switch life loss error corresponding to the switch device and 0, and input the difference into the PI Processing to obtain a first duty cycle compensation value ΔD; adjusting the duty cycle compensation value according to the sign of the switch life loss error corresponding to the switching device to obtain an adjusted first duty cycle compensation value; determining the sign of the duty cycle compensation value according to the subtrahend and the minuend in the switch life loss error calculation formula corresponding to the switching device, the sign of the duty cycle compensation value of the minuend switching device is negative; the sign of the duty cycle compensation value of the subtrahend switching device is positive, and adding the sign of the duty cycle compensation value to the duty cycle compensation value to obtain the first duty cycle compensation value; The adjusted first duty cycle compensation value is superimposed on the initial duty cycle to obtain a control duty cycle corresponding to the switching device, and the switching of the switching device is controlled according to the control duty cycle corresponding to the switching device.

9. An electronic device, characterized in that: The electronic device comprises: at least one processor; and a memory communicatively connected to the at least one processor; wherein, The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the energy storage processing method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to implement the energy storage processing method according to any one of claims 1 to 7 when executed.

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