A bidirectional energy storage converter based on digital control

Abstract

The present invention belongs to the technical field of converter control, and specifically discloses a bidirectional energy storage converter based on digital control, comprising: a converter charging detection module, a converter charging confirmation module, a converter discharge detection module, a converter discharge confirmation module, a converter battery detection module, a converter battery confirmation module and a converter feedback terminal; the present invention confirms the power control information of the bidirectional energy storage converter in the charging mode according to the charging quality information and charging matching information of the bidirectional energy storage converter at each detection time point in the charging mode, thereby ensuring the power quality of the bidirectional energy storage converter and thus improving the operating efficiency of the bidirectional energy storage converter. At the same time, by confirming the battery control information of the bidirectional energy storage converter according to the battery temperature of the bidirectional energy storage converter at each detection time point, the service life of the battery of the bidirectional energy storage converter is ensured, thereby reducing the aging of the battery of the bidirectional energy storage converter.

Description

Technical Field

[0001] The present invention belongs to the technical field of converter control and relates to a bidirectional energy storage converter based on digital control. Background Art

[0002] A bidirectional energy storage converter is a power electronic device that can realize bidirectional flow conversion of electric energy. It can convert alternating current (AC) into direct current (DC) to charge energy storage devices (such as batteries, supercapacitors, etc.), and can also convert DC in energy storage devices into AC to feed back to the power grid or power AC loads.

[0003] The current control analysis of bidirectional energy storage converters mainly focuses on the control of charging and discharging modes, and there are still the following deficiencies: 1. Currently, charging and discharging control is only performed based on the operating status of the bidirectional energy storage converter, that is, insufficient attention is paid to the control analysis of the charging and discharging quality of the bidirectional energy storage converter during the charging and discharging process, which cannot guarantee the power quality of the bidirectional energy storage converter, thereby reducing the operating efficiency of the bidirectional energy storage converter, and thus cannot guarantee the stability of the charging and discharging process of the bidirectional energy storage converter.

[0004] 2. Currently, during the charging and discharging process of the bidirectional energy storage converter, only the electrical parameter conditions during the charging and discharging process are considered, and the battery status of the bidirectional energy storage converter during the charging and discharging process is not considered. This cannot guarantee the service life of the battery of the bidirectional energy storage converter, which in turn leads to accelerated aging of the battery of the bidirectional energy storage converter, resulting in a decrease in the performance of the battery of the bidirectional energy storage converter, and at the same time leads to a decrease in the energy utilization efficiency of the bidirectional energy storage converter, and an increase in the risk of failure of the bidirectional energy storage converter. Summary of the Invention

[0005] In view of this, in order to solve the problems raised in the above background technology, a bidirectional energy storage converter based on digital control is proposed.

[0006] The objectives of the present invention can be achieved through the following technical solutions: The present invention provides a bidirectional energy storage converter based on digital control, including: a converter charging detection module, which is used to detect the charging quality information and charging matching information of the bidirectional energy storage converter at each detection time point in the charging mode, wherein the charging quality information includes the harmonic order, harmonic amplitude, harmonic phase, charging power and charging efficiency, and the charging matching information includes the charging current.

[0007] The converter charging confirmation module is used to confirm the power control information of the bidirectional energy storage converter in the charging mode according to the charging quality information and charging matching information of the bidirectional energy storage converter at each detection time point in the charging mode.

[0008] The converter discharge detection module is used to detect the discharge quality information and discharge matching information of the bidirectional energy storage converter at each detection time point in the discharge mode. The discharge quality information includes the harmonic order, harmonic amplitude, harmonic phase, discharge power and discharge efficiency, and the discharge matching information includes the discharge current.

[0009] The converter discharge confirmation module is used to confirm the power control information of the bidirectional energy storage converter in the discharge mode according to the charging quality information and charging matching information of the bidirectional energy storage converter at each detection time point in the discharge mode, in the same way as the confirmation method of the power control information of the bidirectional energy storage converter in the charging mode.

[0010] The converter battery detection module is used to detect the battery temperature of the bidirectional energy storage converter at each detection time point.

[0011] The converter battery confirmation module is used to confirm the battery control information of the bidirectional energy storage converter according to the battery temperature of the bidirectional energy storage converter at each detection time point.

[0012] The converter feedback terminal is used to provide corresponding control feedback on the bidirectional energy storage converter control cloud platform based on the power control information of the bidirectional energy storage converter in the charging mode and the discharging mode and the battery control information of the bidirectional energy storage converter.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The present invention confirms the power control information of the bidirectional energy storage converter in the charging mode according to the charging quality information and charging matching information of the bidirectional energy storage converter at each detection time point in the charging mode, thereby avoiding the current problem of insufficient attention to the analysis of the charging and discharging quality control of the bidirectional energy storage converter in the charging and discharging process, ensuring the power quality of the bidirectional energy storage converter, and further improving the operating efficiency of the bidirectional energy storage converter, thereby ensuring the stability of the bidirectional energy storage converter in the charging process.

[0014] (2) The present invention confirms the battery control information of the bidirectional energy storage converter according to the battery temperature of the bidirectional energy storage converter at each detection time point, thereby breaking the current deficiency of not considering the battery status of the bidirectional energy storage converter during the charging and discharging process, ensuring the service life of the battery of the bidirectional energy storage converter, and further reducing the aging of the battery of the bidirectional energy storage converter, thereby improving the battery performance of the bidirectional energy storage converter, while ensuring the energy utilization efficiency of the bidirectional energy storage converter and reducing the risk of failure of the bidirectional energy storage converter.

[0015] (3) The present invention confirms the harmonic qualified index of the bidirectional energy storage converter in the charging mode by analyzing the harmonic order qualified index, the harmonic amplitude qualified index and the harmonic phase qualified index, thereby improving the accuracy of the harmonic impact analysis of the bidirectional energy storage converter, and further improving the effectiveness of the power quality assessment of the bidirectional energy storage converter, thereby reducing the damage of harmonics to the bidirectional energy storage converter. At the same time, by setting the weights of the harmonic order qualified index, the harmonic amplitude qualified index and the harmonic phase qualified index, the accuracy of the harmonic qualified index confirmation of the bidirectional energy storage converter in the charging mode is improved, and the comprehensiveness of the harmonic impact assessment of the bidirectional energy storage converter is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing 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.

[0017] Figure 1 This is a schematic diagram of the connection of various modules of the system of the present invention.

[0018] Figure 2 Schematic diagram of the connection of the power control information confirmation step in the charging mode of the present invention.

[0019] Figure 3 This is a connection diagram of the battery control information confirmation step of the present invention. DETAILED DESCRIPTION

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 making creative efforts are within the scope of protection of the present invention.

[0021] See also Figure 1 As shown, the present invention provides a bidirectional energy storage converter based on digital control, including: a converter charging detection module, a converter charging confirmation module, a converter discharge detection module, a converter discharge confirmation module, a converter battery detection module, a converter battery confirmation module and a converter feedback terminal.

[0022] In the above, the converter charging confirmation module is respectively connected to the converter charging detection module and the converter feedback terminal, the converter discharge confirmation module is respectively connected to the converter discharge detection module, the converter charging confirmation module and the converter feedback terminal, and the converter battery confirmation module is also respectively connected to the converter battery detection module and the converter feedback terminal.

[0023] The converter charging detection module is used to detect the charging quality information and charging matching information of the bidirectional energy storage converter at each detection time point in the charging mode. The charging quality information includes the harmonic order, harmonic amplitude, harmonic phase, charging power and charging efficiency, and the charging matching information includes the charging current.

[0024] It should be added that the method of obtaining the harmonic order, harmonic amplitude and harmonic phase of the bidirectional energy storage converter at each detection time point in the charging mode is: obtained through detection by a power quality analyzer placed on the bidirectional energy storage converter. Its working principle is: the signal acquisition module equipped with the power quality analyzer is connected to the relevant circuit nodes of the bidirectional energy storage converter. For example, the power quality analyzer is connected to the AC side input terminal, DC side port and other key parts of the converter, so that the voltage, current and other electrical signals in the circuit can be obtained in real time. For the AC side signal, it can discretize the periodically changing voltage and current waveforms at a certain sampling frequency to ensure that enough data points are collected to accurately reflect the waveform characteristics. The DC side signal is also collected in real time with high precision to prepare for subsequent analysis. The collected electrical signals are usually in analog form. The ADC circuit in the power quality analyzer will convert the analog voltage and current signals into digital signals according to the set resolution and conversion rate. The converted digital signals can use binary codes to represent the corresponding voltage, current amplitude and other information. After the digital signal enters the processor, a specific harmonic analysis algorithm will be used to extract harmonic related information. Common ones include the fast Fourier transform (FFT) algorithm, which can convert discrete signals in the time domain to the frequency domain, thereby clearly showing the different frequency components contained in the signal, that is, accurately obtaining the components corresponding to each harmonic order, and then determining the amplitude of each harmonic by calculating the frequency domain signal amplitude. The corresponding harmonic phase can also be obtained based on the phase information of each harmonic component in the frequency domain, that is, the harmonic order, harmonic amplitude and harmonic phase can be obtained through the harmonic analysis algorithm.

[0025] It should be added that the charging power of the bidirectional energy storage converter at each detection time point in the charging mode is obtained by detection through a power analyzer placed on the bidirectional energy storage converter. Its working principle is: the power analyzer collects current signals through a Hall current sensor. The Hall current sensor is based on the Hall effect. When current passes through the current-carrying conductor, a Hall potential will be generated in the direction perpendicular to the current and the magnetic field. Its magnitude is proportional to the current. The current is indirectly measured by measuring the Hall potential. The voltage transformer can convert high voltage into low voltage in proportion to make it suitable for the measurement range of the power analyzer. The collected analog voltage and current signals are then processed through the built-in high-speed sampling circuit and high-precision analog-to-digital converter of the power analyzer. The converter discretizes and samples the analog signal according to the set sampling frequency and converts it into a digital signal. At the same time, in order to improve the signal quality and measurement accuracy, the power analyzer will filter the collected signal to remove noise and interference components in the signal. Common filtering methods include low-pass filtering, high-pass filtering, band-pass filtering, etc. The appropriate filtering method can be selected according to the actual measurement requirements. For the discrete voltage and current digital signals, the power analyzer will calculate their instantaneous power point by point. In the DC system, the instantaneous power is equal to the product of the voltage value and the current value. In the AC system, the calculation formula of the instantaneous power is P=U*I, where P is the instantaneous power, U is the instantaneous voltage, and I is the instantaneous current.

[0026] It should be added that the charging efficiency of the bidirectional energy storage converter at each detection time point in charging mode is obtained through detection by a power analyzer installed on the bidirectional energy storage converter. Its working principle is as follows: the power analyzer can simultaneously measure parameters such as voltage and current, and calculate the power based on the built-in algorithm. In charging mode, it measures the AC power on the input side of the bidirectional energy storage converter and the DC power on the output side, and then calculates the charging efficiency at each detection time point based on the charging efficiency calculation formula: Charging efficiency = (output DC power / input AC power).

[0027] It should be added that the charging current of the bidirectional energy storage converter at each detection time point in the charging mode is detected by a current sensor installed on the bidirectional energy storage converter.

[0028] The converter charging confirmation module is used to confirm the power control information of the bidirectional energy storage converter in the charging mode according to the charging quality information and charging matching information of each detection time point of the bidirectional energy storage converter in the charging mode.

[0029] See also Figure 2 As shown, exemplarily, the confirming of the power control information of the bidirectional energy storage converter in the charging mode includes: A1, confirming the power quality control information of the bidirectional energy storage converter in the charging mode according to the charging quality information of the bidirectional energy storage converter at each detection time point in the charging mode.

[0030] Furthermore, the confirmation of the power quality control information of the bidirectional energy storage converter in the charging mode includes: A1-1, according to the harmonic order, harmonic amplitude and harmonic phase of each detection time point of the bidirectional energy storage converter in the charging mode, calculating the harmonic qualification index φ1 of the bidirectional energy storage converter in the charging mode.

[0031] Furthermore, the statistical harmonic qualification index of the bidirectional energy storage converter in the charging mode includes: A1-1-1, comparing the harmonic order of the bidirectional energy storage converter at each detection time point in the charging mode with the set permissible harmonic order.

[0032] A1-1-2. If the harmonic order of the bidirectional energy storage converter at a certain detection time point in the charging mode is less than or equal to the set permissible harmonic order, the detection time point is recorded as the harmonic qualified detection time point.

[0033] A1-1-3. Count the number of harmonic qualified detection time points and the number of detection time points, and use the ratio of the number of harmonic qualified detection time points to the number of detection time points as the harmonic order qualified index of the bidirectional energy storage converter in charging mode, denoted as η1.

[0034] A1-1-4. Use the same analysis method as η1 to obtain the harmonic amplitude qualification index and harmonic phase qualification index of the bidirectional energy storage converter in charging mode, and record them as η2 and η3 respectively.

[0035] A1-1-5. Calculate the harmonic qualification index φ1 of the bidirectional energy storage converter in charging mode. φ1 = η1*w1 + η2*w2 + η3*w3, where w1, w2, and w3 are the weights of the set harmonic order qualification index, harmonic amplitude qualification index, and harmonic phase qualification index, respectively. w1+w2+w3=1, w2>w1>w3.

[0036] It should be added that during the charging process, high-amplitude harmonics may cause the voltage or current to exceed the rated value of the equipment. For example, if the charging voltage output by the bidirectional energy storage converter contains high-amplitude harmonics, when these harmonics are superimposed on the fundamental voltage, the voltage across the energy storage device (such as a battery) will exceed its maximum allowable charging voltage, causing the battery to overcharge. For lithium-ion batteries, overcharging may cause the electrolyte inside the battery to decompose, generate gas, and cause the battery to bulge. In severe cases, it may even cause combustion or explosion. Specific harmonic orders may cause circuit resonance. The bidirectional energy storage converter charging circuit and the power grid and energy storage system connected to it contain energy storage elements such as inductors and capacitors. When the harmonic frequency (determined by the harmonic order and the fundamental frequency) is equal to the natural frequency of the circuit, resonance will occur. For example, in a circuit containing filter capacitors and line inductors, In a circuit, if a certain harmonic order occurs so that its frequency is exactly the same as the natural frequency of the LC circuit, the harmonic voltage or current will be greatly amplified, which may cause the device to withstand voltage or current far exceeding normal conditions, posing a serious threat to device safety. The harmonic phase mainly affects the superposition effect of harmonics. In most cases, as long as the harmonic amplitude and order are within a reasonable range, the change in harmonic phase will have relatively little direct harm to the device. For example, during the charging process, the difference in harmonic phase will cause the shape of the voltage or current waveform to change, but as long as the harmonic amplitude does not exceed the withstand voltage and current carrying capacity of the device, the harmonic order will not cause resonance and other problems, and the device can usually operate normally. Therefore, set w2>w1>w3. For ease of analysis, w1 can be specifically set to 0.3, w2 can be specifically set to 0.5, and w3 can be specifically set to 0.2.

[0037] The embodiment of the present invention confirms the harmonic qualified index of the bidirectional energy storage converter in the charging mode by analyzing the harmonic order qualified index, the harmonic amplitude qualified index and the harmonic phase qualified index, thereby improving the accuracy of the harmonic impact analysis of the bidirectional energy storage converter, thereby improving the effectiveness of the power quality assessment of the bidirectional energy storage converter, and thus reducing the damage of harmonics to the bidirectional energy storage converter. At the same time, by setting the weights of the harmonic order qualified index, the harmonic amplitude qualified index and the harmonic phase qualified index, the accuracy of the harmonic qualified index confirmation of the bidirectional energy storage converter in the charging mode is improved, and the comprehensiveness of the harmonic impact assessment of the bidirectional energy storage converter is improved.

[0038] A1-2. According to the charging power rate of the bidirectional energy storage converter at each detection time point in the charging mode, a charging power qualification index φ2 of the bidirectional energy storage converter in the charging mode is calculated.

[0039] Furthermore, the statistical charging power qualification index of the bidirectional energy storage converter in the charging mode includes: A1-2-1, importing the charging power and the charging power qualification range of the bidirectional energy storage converter at each detection time point in the charging mode into the charging power qualification analysis model to obtain the charging power qualification index of the bidirectional energy storage converter at each detection time point in the charging mode.

[0040] It should be added that the specific analysis steps of the charging power qualification analysis model are: comparing the charging power of the bidirectional energy storage converter at each detection time point in the charging mode with the charging power qualification range.

[0041] If the charging power of the bidirectional energy storage converter at a certain detection time point in the charging mode is greater than the upper limit of the charging power qualified range, the ratio of the upper limit of the charging power qualified range to the charging power is used as the charging power qualified index of the bidirectional energy storage converter at the detection time point in the charging mode.

[0042] If the charging power of the bidirectional energy storage converter at a certain detection time point in the charging mode is within the qualified charging power range, 1 is used as the qualified charging power index of the bidirectional energy storage converter at the certain detection time point in the charging mode.

[0043] If the charging power of the bidirectional energy storage converter at a certain detection time point in the charging mode is less than the lower limit of the charging power qualified range, the ratio of the charging power to the lower limit of the charging power qualified range is used as the charging power qualified index of the bidirectional energy storage converter at the detection time point in the charging mode, and then the charging power qualified index of the bidirectional energy storage converter at each detection time point in the charging mode is obtained.

[0044] A1-2-2. Calculate the average of the charging power qualification index of the bidirectional energy storage converter at each detection time point in the charging mode, and use the calculation result as the charging power qualification index of the bidirectional energy storage converter in the charging mode, denoted as φ2.

[0045] A1-3. The charging efficiency qualification index of the bidirectional energy storage converter in the charging mode is obtained by the same statistical method as φ2, which is recorded as φ3.

[0046] A1-4. Calculate the power quality index of the bidirectional energy storage converter in charging mode φ1′, φ2′ and φ3′ are the reference harmonic qualification index, charging power qualification index and charging efficiency qualification index respectively.

[0047] It should be added that φ1′, φ2′, and φ3′ are all historical data extracted from the bidirectional energy storage converter control cloud platform, and then analyzed in the same way as φ1, φ2, and φ3.

[0048] A1-5. Compare the power quality qualification index of the bidirectional energy storage converter in the charging mode with the set reference power quality qualification index.

[0049] A1-6. If the power quality qualification index of the bidirectional energy storage converter in the charging mode is greater than the set reference power quality qualification index, charging will continue as the power quality control information of the bidirectional energy storage converter in the charging mode. Otherwise, a charging quality abnormality warning will be issued as the power quality control information of the bidirectional energy storage converter in the charging mode.

[0050] A2. Confirming power matching control information of the bidirectional energy storage converter in the charging mode according to charging matching information of each detection time point of the bidirectional energy storage converter in the charging mode.

[0051] Furthermore, the confirmation of the power matching control information of the bidirectional energy storage converter in the charging mode includes: A2-1, according to the charging current of the bidirectional energy storage converter at each detection time point in the charging mode, counting the charging current change rate θ1 of the bidirectional energy storage converter in the charging mode.

[0052] Furthermore, the statistical calculation of the charging current change rate of the bidirectional energy storage converter in the charging mode includes: A2-1-1, combining each detection time point of the bidirectional energy storage converter in the charging mode with its adjacent next detection time point in pairs to obtain each detection time group of the bidirectional energy storage converter in the charging mode.

[0053] A2-1-2. Subtract the charging current of the bidirectional energy storage converter in each detection time group under the charging mode to obtain the charging current difference of the bidirectional energy storage converter in each detection time group under the charging mode, and use the ratio of the charging current difference to the set reference charging current difference as the charging current change rate of the bidirectional energy storage converter in each detection time group under the charging mode.

[0054] A2-1-3. Filter out the maximum value from the above charging current change rates as the charging current change rate of the bidirectional energy storage converter in the charging mode, and record it as θ1.

[0055] A2-2. Calculate the charging current matching ratio θ2 of the bidirectional energy storage converter in the charging mode based on the charging current of the bidirectional energy storage converter at each detection time point in the charging mode.

[0056] Furthermore, the statistical charging current matching ratio of the bidirectional energy storage converter in the charging mode includes: A2-2-1, matching and comparing the charging current of the bidirectional energy storage converter at each detection time point in the charging mode with the permitted current range of its energy storage device.

[0057] A2-2-2. If the charging current of the bidirectional energy storage converter at a certain detection time point in the charging mode is within the allowable current range of its energy storage device, then the detection time point is recorded as the charging current matching detection time point.

[0058] A2-2-3. Count the number of charging current matching detection time points, and use the ratio of the number of detection time points to the number of charging current matching ratios of the bidirectional energy storage converter in the charging mode, denoted as θ2.

[0059] A2-3. Calculate the energy matching index ψ of the bidirectional energy storage converter in charging mode. e is a natural constant, θ1′ and θ2′ are the set charging current change rate and charging current matching ratio respectively.

[0060] It should be added that both θ1′ and θ2′ are obtained by extracting historical data from the bidirectional energy storage converter control cloud platform, and then analyzing them in the same way as θ1 and θ2.

[0061] A2-4. Compare the power matching index of the bidirectional energy storage converter in the charging mode with the set reference power matching index.

[0062] A2-5. If the power matching index of the bidirectional energy storage converter in the charging mode is greater than or equal to the set reference power matching index, charging will continue as the power matching control information of the bidirectional energy storage converter in the charging mode; otherwise, charging will be stopped as the power matching control information of the bidirectional energy storage converter in the charging mode.

[0063] A3. Use the power quality control information and power matching control information of the bidirectional energy storage converter in the charging mode as the power control information of the bidirectional energy storage converter in the charging mode.

[0064] The converter discharge detection module is used to detect the discharge quality information and discharge matching information of the bidirectional energy storage converter at each detection time point in the discharge mode. The discharge quality information includes the harmonic order, harmonic amplitude, harmonic phase, discharge power and discharge efficiency, and the discharge matching information includes the discharge current.

[0065] It should be added that the methods for obtaining the harmonic order, harmonic amplitude, harmonic phase, discharge power, discharge efficiency and discharge current of the bidirectional energy storage converter at each detection time point in the discharge mode are the same as the methods for obtaining the harmonic order, harmonic amplitude, harmonic phase, discharge power, discharge efficiency and discharge current of the bidirectional energy storage converter at each detection time point in the charging mode, and will not be repeated here.

[0066] The converter discharge confirmation module is used to confirm the power control information of the bidirectional energy storage converter in the discharge mode according to the charging quality information and charging matching information of the bidirectional energy storage converter at each detection time point in the discharge mode, in the same way as the confirmation method of the power control information of the bidirectional energy storage converter in the charging mode.

[0067] The converter battery detection module is used to detect the battery temperature of the bidirectional energy storage converter at each detection time point.

[0068] It should be noted that the battery temperature of the bidirectional energy storage converter at each test point is detected by a semiconductor temperature sensor installed in the bidirectional energy storage converter. Its operating principle is to measure temperature by leveraging the temperature-dependent resistivity of semiconductor materials or the temperature-dependent forward voltage of semiconductor PN junctions. As the temperature rises, the semiconductor's resistivity decreases, or the PN junction's forward voltage decreases. The temperature value is then determined by measuring the change in resistance or voltage of the semiconductor sensor and processing the signal through the appropriate signal processing circuit.

[0069] The embodiments of the present invention confirm the power control information of the bidirectional energy storage converter in the charging mode based on the charging quality information and charging matching information of the bidirectional energy storage converter at each detection time point in the charging mode, thereby avoiding the current problem of insufficient attention to the analysis of the charging and discharging quality control of the bidirectional energy storage converter during the charging and discharging process, ensuring the power quality of the bidirectional energy storage converter, and further improving the operating efficiency of the bidirectional energy storage converter, thereby ensuring the stability of the bidirectional energy storage converter during the charging process.

[0070] The converter battery confirmation module is used to confirm the battery control information of the bidirectional energy storage converter according to the battery temperature of the bidirectional energy storage converter at each detection time point.

[0071] See also Figure 3 As shown, exemplarily, the confirming of the battery control information of the bidirectional energy storage converter includes: G1, calculating a battery temperature qualification index ξ of the bidirectional energy storage converter according to the battery temperature of the bidirectional energy storage converter at each detection time point.

[0072] Furthermore, the statistical calculation of the battery temperature qualification index of the bidirectional energy storage converter includes: G1-1, matching and comparing the battery temperature of the bidirectional energy storage converter at each detection time point with the battery temperature range corresponding to each battery temperature qualification index, thereby obtaining the battery temperature qualification index of the bidirectional energy storage converter at each detection time point.

[0073] G1-2. Filter out the minimum value from the battery temperature qualification indexes of the bidirectional energy storage converter at each detection time point as the battery temperature qualification index of the bidirectional energy storage converter, which is recorded as ξ.

[0074] G2. Compare the battery temperature qualification index of the bidirectional energy storage converter with the set reference battery temperature qualification index.

[0075] G3. If the battery temperature qualification index of the bidirectional energy storage converter is greater than or equal to the set reference battery temperature qualification index, the battery safety is used as the battery control information of the bidirectional energy storage converter. Otherwise, the battery abnormality warning is used as the battery control information of the bidirectional energy storage converter.

[0076] The embodiment of the present invention confirms the battery control information of the bidirectional energy storage converter based on the battery temperature of the bidirectional energy storage converter at each detection time point, breaking the current deficiency of not considering the battery status of the bidirectional energy storage converter during the charging and discharging process, ensuring the service life of the battery of the bidirectional energy storage converter, and further reducing the aging of the battery of the bidirectional energy storage converter, thereby improving the battery performance of the bidirectional energy storage converter, while ensuring the energy utilization efficiency of the bidirectional energy storage converter and reducing the risk of failure of the bidirectional energy storage converter.

[0077] The converter feedback terminal is used to perform corresponding control feedback on the bidirectional energy storage converter control cloud platform according to the power control information of the bidirectional energy storage converter in the charging mode and the discharging mode and the battery control information of the bidirectional energy storage converter.

[0078] The above contents are merely examples and explanations of the concept of the present invention. Those skilled in the art may make various modifications or additions to the described specific embodiments or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the present invention, they should all fall within the scope of protection of the present invention.

Claims

1. A bidirectional energy storage converter based on digital control, characterized by: include: The converter charging monitoring module is used to monitor the charging quality information and charging matching information of the bidirectional energy storage converter at each detection time point in the charging mode. The charging quality information includes the harmonic order, harmonic amplitude, harmonic phase, charging power and charging efficiency. The charging matching information includes the charging current. The converter charging confirmation module is used to confirm the power control information of the bidirectional energy storage converter in the charging mode, including power quality control information and power matching control information, based on the charging quality information and charging matching information of the bidirectional energy storage converter at each detection time point in the charging mode; The converter discharge monitoring module is used to monitor the discharge quality information and discharge matching information of the bidirectional energy storage converter at each detection time point in the discharge mode. The discharge quality information includes the harmonic order, harmonic amplitude, harmonic phase, discharge power and discharge efficiency. The discharge matching information includes the discharge current. The converter discharge confirmation module is used to confirm the power control information of the bidirectional energy storage converter in the discharge mode based on the charging quality information and charging matching information of the bidirectional energy storage converter at each detection time point in the discharge mode, in the same way as the power control information of the bidirectional energy storage converter in the charging mode is confirmed; The converter battery monitoring module is used to monitor the battery temperature of the bidirectional energy storage converter at each detection time point; The converter battery confirmation module is used to confirm the battery control information of the bidirectional energy storage converter according to the battery temperature of the bidirectional energy storage converter at each detection time point; The converter feedback terminal is used to provide corresponding control feedback on the bidirectional energy storage converter control cloud platform based on the power control information of the bidirectional energy storage converter in the charging mode and the discharging mode and the battery control information of the bidirectional energy storage converter; Confirm power quality control information, including: According to the harmonic order, harmonic amplitude and harmonic phase of the bidirectional energy storage converter at each detection time point in the charging mode, the harmonic qualification index of the bidirectional energy storage converter in the charging mode is calculated. ; According to the charging power of the bidirectional energy storage converter at each detection time point in the charging mode, the charging power qualification index of the bidirectional energy storage converter in the charging mode is calculated. ; according to The charging efficiency qualification index of the bidirectional energy storage converter in the charging mode is obtained by the same statistical method, which is recorded as ; Statistical analysis of the power quality index of the bidirectional energy storage converter in charging mode , , 、 and They are the reference harmonic qualified index, charging power qualified index and charging efficiency qualified index respectively; Will Compare with the set reference power quality index; like If the power quality index is greater than the set reference power quality index, charging will continue as the power quality control information of the bidirectional energy storage converter in the charging mode; otherwise, an abnormal charging quality warning will be issued as the power quality control information of the bidirectional energy storage converter in the charging mode; Confirm power matching control information, including: According to the charging current of the bidirectional energy storage converter at each detection time point in the charging mode, the charging current change rate of the bidirectional energy storage converter in the charging mode is calculated ; According to the charging current of the bidirectional energy storage converter at each detection time point in the charging mode, the charging current matching ratio of the bidirectional energy storage converter in the charging mode is calculated. ; Statistical analysis of the energy matching index of the bidirectional energy storage converter in charging mode , , is a natural constant, and They are the set charging current change rate and charging current matching ratio respectively; Will Compare with the set reference power matching index; like If the power matching index is greater than or equal to the set reference power matching index, charging will continue as the power matching control information of the bidirectional energy storage converter in the charging mode; otherwise, charging will be stopped as the power matching control information of the bidirectional energy storage converter in the charging mode.

2. The digitally controlled bidirectional energy storage converter according to claim 1, characterized in that: The confirming of the electric energy control information of the bidirectional energy storage converter in the charging mode includes: A1. Determine power quality control information of the bidirectional energy storage converter in the charging mode based on charging quality information of the bidirectional energy storage converter at each detection time point in the charging mode; A2. confirming the power matching control information of the bidirectional energy storage converter in the charging mode according to the charging matching information of each detection time point of the bidirectional energy storage converter in the charging mode; A3. Use the power quality control information and power matching control information of the bidirectional energy storage converter in the charging mode as the power control information of the bidirectional energy storage converter in the charging mode.

3. The digitally controlled bidirectional energy storage converter according to claim 1, characterized in that: The statistical harmonic qualification index of the bidirectional energy storage converter in the charging mode includes: Compare the harmonic order of the bidirectional energy storage converter at each detection time point in the charging mode with the set permissible harmonic order; If the harmonic order of the bidirectional energy storage converter at a certain detection time point in the charging mode is less than or equal to the set permissible harmonic order, the detection time point is recorded as the harmonic qualified detection time point; The number of harmonic qualified detection time points and the number of detection time points are counted, and the ratio of the number of harmonic qualified detection time points to the number of detection time points is used as the harmonic order qualified index of the bidirectional energy storage converter in the charging mode, which is recorded as ; according to The harmonic amplitude qualification index and harmonic phase qualification index of the bidirectional energy storage converter in charging mode are obtained by the same analysis method, and are recorded as and ; Statistical analysis of the harmonic qualification index of bidirectional energy storage converters in charging mode , , 、 and The weights of the set harmonic order qualification index, harmonic amplitude qualification index and harmonic phase qualification index are respectively, , .

4. The digitally controlled bidirectional energy storage converter according to claim 1, characterized in that: The statistical charging power qualification index of the bidirectional energy storage converter in the charging mode includes: The charging power of the bidirectional energy storage converter at each detection time point in the charging mode is introduced into the charging power qualification analysis model to obtain the charging power qualification index of the bidirectional energy storage converter at each detection time point in the charging mode; The charging power qualified index of the bidirectional energy storage converter at each detection time point in the charging mode is averaged and the calculation result is used as the charging power qualified index of the bidirectional energy storage converter in the charging mode, which is recorded as .

5. The digitally controlled bidirectional energy storage converter according to claim 1, characterized in that: The method of calculating the charging current change rate of the bidirectional energy storage converter in the charging mode includes: Combining each detection time point of the bidirectional energy storage converter in the charging mode with its next adjacent detection time point in pairs to obtain detection time groups of the bidirectional energy storage converter in the charging mode; The charging current of the bidirectional energy storage converter in each detection time group in the charging mode is subtracted to obtain the charging current difference of each detection time group in the charging mode, and the ratio of the charging current difference to the set reference charging current difference is used as the charging current change rate of each detection time group in the charging mode of the bidirectional energy storage converter; The maximum value is selected from the above charging current change rates as the charging current change rate of the bidirectional energy storage converter in the charging mode, which is recorded as .

6. The digitally controlled bidirectional energy storage converter according to claim 1, characterized in that: The method of calculating the charging current matching ratio of the bidirectional energy storage converter in the charging mode includes: Match and compare the charging current of the bidirectional energy storage converter at each detection time point in the charging mode with the permitted current range of its energy storage device; If the charging current of the bidirectional energy storage converter at a certain detection time point in the charging mode is within the allowable current range of its energy storage device, then the detection time point is recorded as the charging current matching detection time point; The number of charging current matching detection time points is counted, and the ratio of the number of detection time points to the number of detection time points is used as the charging current matching ratio of the bidirectional energy storage converter in the charging mode, which is recorded as .

7. The digitally controlled bidirectional energy storage converter according to claim 1, characterized in that: The confirming of battery control information of the bidirectional energy storage converter includes: G1. Calculate the battery temperature qualification index of the bidirectional energy storage converter based on the battery temperature of the bidirectional energy storage converter at each detection time point. ; G2. Compare the battery temperature qualification index of the bidirectional energy storage converter with the set reference battery temperature qualification index; G3. If the battery temperature qualification index of the bidirectional energy storage converter is greater than or equal to the set reference battery temperature qualification index, the battery safety is used as the battery control information of the bidirectional energy storage converter. Otherwise, the battery abnormality warning is used as the battery control information of the bidirectional energy storage converter.

8. The digitally controlled bidirectional energy storage converter according to claim 7, characterized in that: The statistical calculation of the battery temperature qualification index of the bidirectional energy storage converter includes: The battery temperature of the bidirectional energy storage converter at each detection time point is matched and compared with the battery temperature range corresponding to each battery temperature qualification index, thereby obtaining the battery temperature qualification index of the bidirectional energy storage converter at each detection time point; The minimum value is selected from the battery temperature qualification index of the bidirectional energy storage converter at each detection time point as the battery temperature qualification index of the bidirectional energy storage converter, which is recorded as .

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