ANPC modulation circuit for energy storage converter and energy storage system

Abstract

The utility model provides an ANPC modulation circuit for an energy storage converter and an energy storage system. The ANPC modulation circuit comprises a power conversion module which is connected with an energy storage power supply; the filtering module is connected with the power conversion module; the first end of the circuit breaker is connected with the filtering module; the power grid layer is connected with the second end of the circuit breaker; the sampling module updates the collected analog signal into control cycle data of the PWM signal; the pulse width modulation module converts the PWM signal into a driving signal used for adjusting the turn-on and turn-off efficiency of the power conversion module. Sampling modules are arranged at the two ends of a circuit breaker, and the collected power grid voltage, the output current of a power conversion module and the inverter voltage are updated into control cycle data of PWM signals in real time; and then the PWM signal is converted into a driving signal used for adjusting the turn-on and turn-off efficiency of the power conversion module through the pulse width modulation module, so that zero-voltage circulation is realized, the switching loss of power conversion is reduced, the safety of the energy storage system is greatly improved, and the energy storage system has wide application value.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power electronics, and particularly relates to an ANPC modulation circuit for an energy storage converter and an energy storage system. BACKGROUND

[0002] In order to improve energy conversion efficiency and power system reliability, especially in high-power and high-voltage energy storage systems, how to adaptively adjust the higher DC side voltage, how to improve the dynamic voltage regulation point adjustment capability, how to reduce heat loss, how to improve system thermal efficiency, how to reduce thermal stress, and how to prolong the service life of the equipment are technical problems to be solved in the energy storage system.

[0003] It should be noted that the above introduction to the technical background is only for the convenience of clearly and completely describing the technical scheme of the present application and facilitating the understanding of those skilled in the art. The above technical scheme cannot be considered as known to those skilled in the art merely because it is described in the background section of the present application. CONTENT OF THE INVENTION

[0004] The present application aims to solve at least one of the technical problems in the related art.

[0005] To this end, one object of the present application is to provide an ANPC modulation circuit for an energy storage converter, comprising: an energy storage power supply, a power conversion module, a filter module, a circuit breaker, a pulse width modulation module, a sampling module and a grid layer, wherein:

[0006] The power conversion module is connected with the energy storage power supply; the filter module is connected with the power conversion module; the first end of the circuit breaker is connected with the filter module; the second end of the circuit breaker is connected with the grid layer; the sampling module is connected with the first end and the second end of the circuit breaker, and updates the collected grid voltage, output current of the power conversion module and inverter voltage into control period data of a PWM signal in real time; the pulse width modulation module is connected between the sampling module and the power conversion module, and converts the PWM signal into a driving signal for adjusting the opening and closing efficiency of the power conversion module.

[0007] According to the ANPC modulation circuit for an energy storage converter of one embodiment of the present application, the sampling module converts the collected grid voltage, output current of the power conversion module and inverter voltage into a device feedback signal related to the running state of the energy storage power supply, the power conversion module and the grid layer, and the sampling module adjusts the opening and closing of the circuit breaker according to the device feedback signal.

[0008] According to an embodiment of the application, the ANPC modulation circuit for the energy storage converter comprises a sampling module, a first main control unit and a first modulation unit, wherein the signal conditioning unit is connected with the first end and the second end of the circuit breaker, and is used to convert the collected grid voltage, output current of the power conversion module and inverter voltage; the first main control unit is connected with the signal conditioning unit, and is used to update the mode conversion result as control period data of the PWM signal; and the first modulation unit is connected with the first main control unit, and is used to generate the PWM signal according to the control period data.

[0009] According to an embodiment of the application, the signal conditioning unit of the ANPC modulation circuit for the energy storage converter comprises an analog-to-digital converter, a sample-and-hold circuit and a quantizer combination device.

[0010] According to an embodiment of the application, the first main control unit of the ANPC modulation circuit for the energy storage converter comprises a digital signal processor and a microcontroller.

[0011] According to an embodiment of the application, the pulse width modulation module of the ANPC modulation circuit for the energy storage converter comprises a second main control unit and a second modulation unit, wherein the second main control unit is connected with the sampling module, and is used to perform logic and timing detection on the PWM signal; and the second modulation unit is connected with the second main control unit, and is used to generate a driving signal for adjusting the opening and closing efficiency of the power conversion module.

[0012] According to an embodiment of the application, the second main control unit of the ANPC modulation circuit for the energy storage converter comprises a field programmable logic gate array, a complex programmable logic device and a general array logic.

[0013] According to an embodiment of the application, the power conversion module of the ANPC modulation circuit for the energy storage converter comprises an ANPC type three-level topology structure.

[0014] According to an embodiment of the application, the filter module of the ANPC modulation circuit for the energy storage converter comprises an LC filter circuit, an RC filter circuit and an RLC filter circuit.

[0015] To this end, another object of the application is to provide an energy storage system comprising the ANPC modulation circuit for the energy storage converter according to the embodiments of the application.

[0016] In the application, the collected grid voltage, output current of the power conversion module and inverter voltage are updated in real time as control period data of the PWM signal by setting the sampling module at both ends of the circuit breaker; then the PWM signal is converted into a driving signal for regulating the opening and closing efficiency of the power conversion module by the pulse width modulation module, realizing zero voltage circulating current, reducing the switching loss of power conversion, greatly improving the safety of the energy storage system, and having wide application value. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 A structure schematic diagram of an ANPC modulation circuit for an energy storage converter according to an embodiment of the application is shown in

[0018] Figure 2 A structure schematic diagram of a sampling module according to an embodiment of the application is shown in

[0019] Figure 3 A structure schematic diagram of a pulse width modulation module according to an embodiment of the application is shown in

[0020] Figure 4 A structure schematic diagram of a power conversion module according to an embodiment of the application is shown in DETAILED DESCRIPTION

[0021] The embodiments of the application are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference signs represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by reference to the accompanying drawings are exemplary and are intended to explain the application, and cannot be understood as a limitation of the application.

[0022] The ANPC modulation circuit for an energy storage converter and the energy storage system according to the embodiments of the application are described below in conjunction with the accompanying drawings.

[0023] Figure 1 A structure schematic diagram of an ANPC modulation circuit for an energy storage converter according to an embodiment of the application is shown in Figure 1 The ANPC modulation circuit for an energy storage converter according to the embodiments of the application, as shown in the structure schematic diagram, includes an energy storage power supply, a power conversion module, a filter module, a circuit breaker, a pulse width modulation module, a sampling module and a grid layer, wherein:

[0024] The power conversion module is connected with the energy storage power supply, wherein the power conversion module plays a role of electric energy conversion in the energy storage system, can convert the electric energy provided by the energy storage power supply into the electric energy form required by other devices (such as a power grid layer), or can convert the input electric energy into the electric energy form required by the energy storage power supply, that is, the power conversion module can realize AC-DC or DC-DC or DC-AC electric energy conversion to meet the electric energy requirement of different devices; and the energy storage power supply includes a lithium ion battery, a sodium-sulfur battery, a flow battery, a photovoltaic power station and the like. The filter module is connected with the power conversion module, removes the noise and unnecessary frequency components in the output signal of the power conversion module, and retains the required signal components, can realize the smoothing processing of the output signal of the power conversion module, and improves the quality and stability of the signal. The first end of the circuit breaker is connected with the filter module, and the second end is connected with the power grid layer, for providing short circuit protection and overload protection, when a short circuit or overload occurs in the circuit, the circuit breaker can quickly cut off the circuit to prevent the current from being too large to cause damage to the device, on the other hand, the circuit breaker can also be used as a switch of the circuit to control the on-off of the circuit.

[0025] Further, as Figure 1As shown, the sampling module is connected to the first end and the second end of the circuit breaker, and the collected grid voltage, output current of the power conversion module and inverter voltage are updated in real time as control period data of the PWM signal. Specifically, the sampling module can collect key data such as grid voltage, output current of the power conversion module and inverter current in real time through the built-in sensor unit; then the collected data is preliminarily processed, such as filtering, amplification, etc., to improve the accuracy and reliability of the data; the processed data will be converted into control period data of the PWM signal by the sampling module, and the sampling module adjusts the frequency and duty cycle of the PWM signal to realize accurate control of voltage and current, for example, if the power conversion module is set by power devices (such as IGBT, silicon carbide, etc.), the PMW signal can accurately control the opening and closing of the power device, and by controlling the action of the power device, the DC side voltage is adjusted (for example, according to the real-time DC side voltage and the size of the preset voltage difference square value, the output voltage of the power conversion module is feedback adjusted; also can change the reference lower limit of the DC side voltage in real time according to the minimum voltage required by the pulse modulation module; also can reduce the voltage fluctuation of the DC side by adjusting the grid voltage phase shift angle and grid reactive power compensation coefficient), and adjust the dynamic voltage stabilization point of the energy storage system (for example, according to the load condition and grid requirement of the grid layer, adjust the control period data, then the control period data is feedback adjusted to the power conversion module by the pulse width modulation module, thereby adjusting the dynamic voltage stabilization point). On the other hand, the sampling module can also convert the collected grid voltage, output current of the power conversion module and inverter voltage into device feedback signals related to the operating state of the energy storage power supply, power conversion module and grid layer, wherein if the device feedback signal shows an abnormal state, the sampling module can control the opening of the circuit breaker, thereby realizing the protection of the circuit; if the device feedback signal shows a normal state, the sampling module maintains the closing of the circuit breaker.

[0026] Further, as shown in FIG. 1, the sampling module is connected to the first end and the second end of the circuit breaker, and the collected grid voltage, output current of the power conversion module and inverter voltage are updated in real time as control period data of the PWM signal. Specifically, the sampling module can collect key data such as grid voltage, output current of the power conversion module and inverter current in real time through the built-in sensor unit; then the collected data is preliminarily processed, such as filtering, amplification, etc., to improve the accuracy and reliability of the data; the processed data will be converted into control period data of the PWM signal by the sampling module, and the sampling module adjusts the frequency and duty cycle of the PWM signal to realize accurate control of voltage and current, for example, if the power conversion module is set by power devices (such as IGBT, silicon carbide, etc.), the PMW signal can accurately control the opening and closing of the power device, and by controlling the action of the power device, the DC side voltage is adjusted (for example, according to the real-time DC side voltage and the size of the preset voltage difference square value, the output voltage of the power conversion module is feedback adjusted; also can change the reference lower limit of the DC side voltage in real time according to the minimum voltage required by the pulse modulation module; also can reduce the voltage fluctuation of the DC side by adjusting the grid voltage phase shift angle and grid reactive power compensation coefficient), and adjust the dynamic voltage stabilization point of the energy storage system (for example, according to the load condition and grid requirement of the grid layer, adjust the control period data, then the control period data is feedback adjusted to the power conversion module by the pulse width modulation module, thereby adjusting the dynamic voltage stabilization point). On the other hand, the sampling module can also convert the collected grid voltage, output current of the power conversion module and inverter voltage into device feedback signals related to the operating state of the energy storage power supply, power conversion module and grid layer, wherein if the device feedback signal shows an abnormal state, the sampling module can control the opening of the circuit breaker, thereby realizing the protection of the circuit; if the device feedback signal shows a normal state, the sampling module maintains the closing of the circuit breaker. Figure 1As shown, the pulse width modulation module is connected between the sampling module and the power conversion module, and converts the PWM signal into a driving signal for regulating the opening and closing efficiency of the power conversion module. Specifically, the PWM signal is transmitted to the pulse width modulation module based on the updated duty cycle and frequency of the sampling module, and the pulse width modulation module checks whether the logic of the PWM signal is correct, i.e. whether the duration of the high level and the low level meets the preset duty cycle requirement. At the same time, the pulse width modulation module also checks whether there is a logic conflict or inconsistency between the PWM signals; and checks whether the timing of the PWM signal meets the requirements of the power conversion module, which includes parameters such as the period, rise time and fall time of the PWM signal. Through the timing check, it can be ensured that the PWM signal and the input signal of the power conversion module remain synchronized, and the system instability caused by timing errors is avoided. After the logic and timing check, the PWM signal is converted into a driving signal for regulating the opening and closing efficiency of the power conversion module, and the driving signal has the same duty cycle and frequency as the PWM signal. The power conversion module accurately controls the output voltage and current according to the duty cycle and frequency of the driving signal, thereby realizing energy conversion and regulation.

[0027] Optionally, as an example, Figure 2 A structural schematic diagram of a sampling module according to an embodiment of the present application is shown. As shown in the figure, Figure 2 The sampling module includes a signal conditioning unit, a first main control unit and a first modulation unit. The signal conditioning unit is connected to the first end and the second end of the circuit breaker, and performs mode conversion on the collected grid voltage, output current of the power conversion module and inverter voltage. Specifically, the signal conditioning unit includes an analog-to-digital converter, a sample-and-hold circuit and a quantizer combination device. The sample-and-hold circuit can capture the instantaneous value of the grid voltage, output current and inverter voltage within a specific time, and the quantizer converts the instantaneous value into the nearest digital representation. The setting form of the signal conditioning unit should be selected according to the specific use scenario, which will not be described here.

[0028] As shown in the figure, Figure 2As shown, the first master control unit is connected with the signal conditioning unit, and updates the control period data of the PWM signal according to the mode conversion result, wherein the first master control unit calculates the period of the required PWM signal according to the mode conversion result (by adjusting the count value of the count period), and then obtains the duty cycle according to the proportional relationship between the active time of the high level and the period; and then obtains the frequency according to the number of signal repetitions in a unit time. Specifically, the first master control unit includes a digital signal processor and a microcontroller, wherein the digital signal processor (English full name: Digital Signal Processor, abbreviated as DSP) can efficiently process analog signals from the power conversion module and the grid layer, and through the built-in digital signal processing algorithm, the signals are filtered, transformed, demodulated, etc. Operation, thereby realizing accurate monitoring and control of the running state of the power conversion module and the grid layer. As an example, in ANPC modulation, i.e. Active Neutral Point Clamped modulation, the DSP can implement PWM (Pulse Width Modulation) control algorithm, midpoint potential balancing algorithm and other key algorithms, which can improve the conversion efficiency of the power conversion module, reduce the harmonic content, and enhance the stability of the energy storage power generation system. For example, when the load on the grid side changes, the DSP can adjust the duty cycle and frequency of the PWM signal to maintain the stability of the grid voltage, the output current of the power conversion module and the inverter voltage. On the other hand, the microcontroller (English full name: Microcontroller Unit, abbreviated as MCU) is also called single chip microcomputer (Single Chip Microcomputer) or single chip microcomputer. It is to reduce the frequency and specifications of the central processing unit (Central Process Unit; CPU) appropriately, and integrate memory (Memory), counter (Timer), USB, A / D conversion, UART, PLC, DMA and other peripheral interfaces, even LCD driving circuit on a single chip to form a chip-level computer for different application scenarios. As an example, in ANPC modulation, the MCU can process various data from the power conversion module and the grid layer in real time, calculate the switching time of the power conversion module, adjust the duty cycle and frequency of the PWM signal by executing the algorithm required by ANPC modulation, and through rich peripheral interfaces such as UART, SPI, I2C, etc. Data transmission and interaction with the power conversion module, pulse width modulation module and grid layer to realize accurate control and monitoring. The setting form of the first master control unit should be selected according to the specific use scene, which will not be described here. Further, the first modulation unit is connected with the first master control unit, and generates the PWM signal according to the control period data.

[0029] It should be noted that the sampling module can also be set in the form of Application Specific Integrated Circuit (ASIC, which is an integrated circuit designed for specific user requirements and specific system, and is an integrated circuit of special application), IP core (intellectual property core, IP core is a mature design of circuit module with independent function in chip or integrated circuit design, which can be applied in other chip or integrated circuit design project containing the circuit module, so as to reduce the workload of design, shorten the design cycle and improve the success rate of chip or integrated circuit design. IP core has three levels of classification, namely behavior level, structure level and physical level, so there are three types of IP core, which are soft core of hardware description language design, fixed core of structure description and hard core based on physical description and verified by process), and other ways. The specific setting form will not be described here, as long as the collected power grid voltage, power conversion module output current and inverter voltage can be updated to the control period data of PWM signal and converted to the device feedback signal related to the operation state of energy storage power supply, power conversion module and power grid layer. The setting form of any sampling module is applicable, and is not limited to the embodiment.

[0030] Optionally, as an example, Figure 3 A structure diagram of a pulse width modulation module according to an embodiment of the present application is provided. As shown in Figure 3As shown, the pulse width modulation module includes a second master control unit and a second modulation unit. The second master control unit is connected with the sampling module to perform logic and timing detection on the PWM signal. The second master control unit usually has a built-in timer / counter module, which can be used to measure the frequency, period, duty cycle and other parameters of the PWM signal. An interrupt service program can also be configured to respond to the rising edge or falling edge of the PWM signal. In the interrupt service program, specific algorithms can be executed to monitor the logic and timing of the PWM signal, such as detecting the edges of the PWM signal, measuring the state duration, verifying the signal integrity, etc. Specifically, the second master control unit includes a field programmable gate array (FPGA), a complex programmable logic device (CPLD), and a general array logic (GAL). As an example, the FPGA receives the PWM signal through a dedicated input interface. These interfaces usually have high speed and high precision characteristics, which can accurately capture the details of the PWM signal. Then, the FPGA pre-processes the PWM signal, such as filtering, amplifying or level conversion, to ensure the quality and stability of the signal. Next, the FPGA performs logic detection on the edges (including rising edge and falling edge) of the PWM signal and the integrity of the signal (such as whether there are missing pulses or abnormal pulse width) through built-in logic detection algorithms. The FPGA can also perform timing analysis on the PWM signal through built-in counters or timers, including measuring the frequency, period, duty cycle and other parameters of the PWM signal, and comparing them with preset thresholds or conditions. The results of timing detection can be used to verify whether the PWM signal meets specific timing requirements, such as whether it stably sends pulses within a specified time. The process of CPLD and GAL performing logic and timing detection on the PWM signal is not described here, and the setting form of the second master control unit should be selected according to the specific use scenario. Further, the second modulation unit is connected with the second master control unit to generate a driving signal for adjusting the opening and closing efficiency of the power conversion module. It should be noted that the driving signal has the same timing parameters as the PWM signal, such as frequency, period, duty cycle, etc. The power conversion module performs switching operation according to the instructions of the driving signal and accurately controls the switching time, thereby controlling the amplitude and frequency of the output current and inverter voltage and other parameters.

[0031] It should be noted that the pulse width modulation module can also be set in the form of application specific integrated circuit (ASIC), IP core, etc. The specific setting form is not described here, as long as the PWM signal can be converted into a driving signal for adjusting the opening and closing efficiency of the power conversion module. Any setting form of the pulse width modulation module is applicable, and is not limited to this embodiment.

[0032] Optionally, as an example, Figure 4This is a schematic diagram of a power conversion module according to an embodiment of this application. Figure 4 As shown, the power conversion module includes an ANPC three-level topology. The ANPC three-level topology is a multilevel converter based on Neutral Point Clamped (NPC) technology. It achieves three-level output by introducing an additional neutral point on the DC side. The so-called three-level refers to the fact that the AC output voltage of the inverter has three levels relative to the input DC voltage: 1 / 2Vdc at the positive terminal (i.e., the voltage at node P), -1 / 2Vdc at the negative terminal (i.e., the voltage at node N), and 0 (i.e., the voltage at node O). There are two capacitors connected in series on the DC input side to support and balance the DC bus voltage. The three-level phase voltage is generated on the AC side by switching control. After passing through the filtering circuit, a sine wave, i.e., the AC signal, is obtained. As an example, taking phase A, it includes six IGBTs (Insulated Gate Bipolar Transistors, a type of power semiconductor device that combines the advantages of BJTs and MOSFETs, featuring high input impedance, low drive power, fast switching speed, low on-state voltage, high current handling capacity, and high voltage withstand capability), namely T1, T2, T3, T4, T5, and T6. By controlling the on and off states of T5 and T6, redundant circulating current paths can be provided, each IGBT only needs to withstand half of the DC-side voltage, and the uneven distribution of IGBT losses can be resolved.

[0033] Furthermore, such as Figure 4 As shown, a state transition is selected to illustrate the ANPC-type three-level topology. The output current and inverter voltage of the power conversion module are generated from the emitter of T2. The output current can be characterized as I. A The inverter voltage can be characterized as U A , when U A >0, I A>0, the switch state is (110000), (110000) means that the gate of T1 is high, the gate of T2 is high, the gate of T3 is low, the gate of T4 is low, the gate of T5 is low, and the gate of T6 is low, at this time the current path is path 1. If the pulse width modulation module triggers the switching state to be (010010), (010010) means that the gate of T1 is low, the gate of T2 is high, the gate of T3 is low, the gate of T4 is low, the gate of T5 is high, and the gate of T6 is low, at this time the current path is path 2. During the switching process from the switch state (110000) to the switch state (010010), T2 remains conducting, and only the actions of T1 and T5 are changed to achieve the circulation. It should be noted that, due to the existence of redundant levels in the ANPC three-level topology, there may be a current path from T6 to D3, i.e. path 3, wherein D3 is the parasitic diode of T3. The minimum circulation path can be achieved by controlling T2 and T5 to conduct first and T6 and D3 to conduct later, while ensuring the zero-voltage conduction of the T6 to D3 path, thereby avoiding the conduction loss of the IGBT. Similarly, during the switching process from the switch state (010010) to the switch state (110000), T2 remains conducting, and only T1 and T5 act to achieve the circulation. Then, by controlling T6 and D3 to turn off first and T2 and T5 to turn off later, the zero-voltage turn-off of the T6 to D3 path can be ensured, thereby avoiding the turn-off loss of the IGBT. The working principles of other states are similar to the above content and will not be described here. A >0, the switch state is (110000), (110000) means that the gate of T1 is high, the gate of T2 is high, the gate of T3 is low, the gate of T4 is low, the gate of T5 is low, and the gate of T6 is low, at this time the current path is path 1. If the pulse width modulation module triggers the switching state to be (010010), (010010) means that the gate of T1 is low, the gate of T2 is high, the gate of T3 is low, the gate of T4 is low, the gate of T5 is high, and the gate of T6 is low, at this time the current path is path 2. During the switching process from the switch state (110000) to the switch state (010010), T2 remains conducting, and only the actions of T1 and T5 are changed to achieve the circulation. It should be noted that, due to the existence of redundant levels in the ANPC three-level topology, there may be a current path from T6 to D3, i.e. path 3, wherein D3 is the parasitic diode of T3. The minimum circulation path can be achieved by controlling T2 and T5 to conduct first and T6 and D3 to conduct later, while ensuring the zero-voltage conduction of the T6 to D3 path, thereby avoiding the conduction loss of the IGBT. Similarly, during the switching process from the switch state (010010) to the switch state (110000), T2 remains conducting, and only T1 and T5 act to achieve the circulation. Then, by controlling T6 and D3 to turn off first and T2 and T5 to turn off later, the zero-voltage turn-off of the T6 to D3 path can be ensured, thereby avoiding the turn-off loss of the IGBT. The working principles of other states are similar to the above content and will not be described here.

[0034] Further, the switching states of the A phase include six levels, and the switching states of the ANPC three-level topology include eighteen levels, which can be adjusted by the driving signals output by the pulse width modulation module.

[0035] It should be noted that the power conversion module can also be set in the form of an application-specific integrated circuit, a gate circuit, etc. The specific setting forms will not be described here, as long as the switch operation can be performed according to the instructions of the driving signals and the switching time can be accurately controlled to control the amplitude and frequency of the output current and the inverse voltage and other parameters. Any setting form of the power conversion module is applicable, and is not limited to the present embodiment.

[0036] Optionally, as an example, the filtering module includes an LC filter circuit, an RC filter circuit, and an RLC filter circuit. The setting form of the filtering module should be selected according to the actual use scenario, which will not be described here.

[0037] In particular, according to the embodiments of the present application, the ANPC modulation circuit for the energy storage converter referred to above can be implemented as an energy storage system. The energy storage system can achieve zero voltage circulating current by adjusting the control period of the PWM signal, thereby reducing the switching loss of the device and reducing the stray inductance loss of the circulating current path.

[0038] In summary, in the present application, by setting a sampling module at both ends of the circuit breaker, the collected grid voltage, output current of the power conversion module and inverse voltage are updated in real time as control period data of the PWM signal. Then, through the pulse width modulation module, the PWM signal is converted into a driving signal for adjusting the opening and closing efficiency of the power conversion module, achieving zero voltage circulating current, reducing the switching loss of the power conversion, greatly improving the safety of the energy storage system, and having wide application value.

[0039] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0040] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise explicitly specified and limited.

[0041] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0042] In the present application, unless specifically stated and limited otherwise, a first feature "on" or "under" a second feature can be directly contacting the first and second features, or indirectly contacting the first and second features through an intermediate medium. Also, a first feature "over", "above" and "on top of" a second feature can be directly above or obliquely above the second feature, or simply means that the first feature is horizontally higher than the second feature. A first feature "under", "below" and "underneath" a second feature can be directly below or obliquely below the second feature, or simply means that the first feature is horizontally lower than the second feature.

[0043] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are contained in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Also, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the present application and the features of the different embodiments or examples without contradiction.

[0044] Although the embodiments of the present application have been shown and described above, it is understood that the above embodiments are exemplary and are not to be construed as limiting the present application, and the person skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application.

Claims

1. An ANPC modulation circuit for an energy storage converter, characterized by, The application relates to an ANPC modulation circuit for an energy storage converter. The ANPC modulation circuit comprises an energy storage power supply, a power conversion module, a filter module, a circuit breaker, a pulse width modulation module, a sampling module and a power grid layer. The power conversion module is connected with the energy storage power supply; the filter module is connected with the power conversion module; the first end of the circuit breaker is connected with the filter module; the power grid layer is connected with the second end of the circuit breaker; the sampling module is connected with the first end and the second end of the circuit breaker, and the collected power grid voltage, output current and inverter voltage of the power conversion module are updated into control period data of a PWM signal in real time; the pulse width modulation module is connected between the sampling module and the power conversion module, and the PWM signal is converted into a driving signal for regulating the opening and closing efficiency of the power conversion module.

2. The ANPC modulation circuit for an energy storage converter according to claim 1, characterized in that, The application further relates to an ANPC modulation circuit for an energy storage converter. The sampling module converts the collected power grid voltage, output current and inverter voltage into device feedback signals related to the running states of the energy storage power supply, the power conversion module and the power grid layer, wherein the sampling module adjusts the opening and closing of the circuit breaker according to the device feedback signals.

3. The ANPC modulation circuit for an energy storage converter according to claim 1 or 2, characterized in that, The sampling module comprises a signal conditioning unit, a first main control unit and a first modulation unit, wherein the signal conditioning unit is connected with the first end and the second end of the circuit breaker, and mode conversion is performed on the collected power grid voltage, output current and inverter voltage of the power conversion module; the first main control unit is connected with the signal conditioning unit, and the mode conversion result is updated into control period data of a PWM signal; and the first modulation unit is connected with the first main control unit, and a PWM signal is generated according to the control period data.

4. The ANPC modulation circuit for an energy storage converter according to claim 3, characterized in that, The signal conditioning unit comprises an analog-to-digital converter, a sample-and-hold circuit and a quantizer combination device.

5. The ANPC modulation circuit for an energy storage converter according to claim 3, characterized in that, The first main control unit comprises a digital signal processor and a microcontroller.

6. The ANPC modulation circuit for an energy storage converter according to claim 1, characterized in that, The pulse width modulation module comprises a second main control unit and a second modulation unit, wherein the second main control unit is connected with the sampling module, and logic and timing detection are performed on the PWM signal; and the second modulation unit is connected with the second main control unit, and a driving signal for regulating the opening and closing efficiency of the power conversion module is generated.

7. The ANPC modulation circuit for an energy storage converter according to claim 6, characterized in that, The second main control unit comprises a field programmable gate array, a complex programmable logic device and a general array logic.

8. The ANPC modulation circuit for an energy storage converter according to claim 1, characterized in that, The power conversion module comprises an ANPC type three-level topology structure.

9. The ANPC modulation circuit for an energy storage converter according to claim 1, characterized in that, The filter module comprises an LC filter circuit, an RC filter circuit and an RLC filter circuit.

10. An energy storage system characterized by, The energy storage system comprises the ANPC modulation circuit for an energy storage converter according to any one of claims 1-9.

Images