Energy storage converter and control method
By introducing a discharge control unit and an energy conversion unit into the energy storage converter, rapid discharge of the bus capacitor module is achieved, solving the problems of low discharge efficiency and safety of residual energy in the bus support capacitor, and improving the safety and reliability of the equipment.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- JINKO SOLAR CO LTD
- Filing Date
- 2025-02-28
- Publication Date
- 2026-07-21
Smart Images
Figure CN120090445B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of energy storage technology, and in particular to an energy storage converter and control method. Background Technology
[0002] Against the backdrop of energy transition and the construction of new power systems, energy storage has become a very active field in countries around the world. However, the safe and reliable operation of energy storage converters and the power grid system place increasingly stringent requirements on the safety and high reliability of energy storage equipment. Busbar support capacitors, due to their characteristics such as stabilizing DC bus voltage and filtering high-frequency noise, play a crucial role in the operational stability of energy storage converters; therefore, they are widely used in energy storage converters. However, during the operation of the energy storage converter, the busbar support capacitor is in a charging state. After the energy storage converter stops working and is de-energized, the busbar support capacitor still retains high voltage and residual energy.
[0003] The existing traditional discharge method still releases the residual energy of the bus support capacitor through the internal circuit of the energy storage converter. However, the discharge time can be as long as one hour or even longer, resulting in low residual energy discharge efficiency. If the residual energy is not discharged in time, it will generate electric sparks and even pose an explosion risk, as well as electric shock hazards to maintenance and repair personnel. Therefore, how to improve the release efficiency of residual energy of the bus support capacitor to improve the safety of the energy storage converter is a technical problem that urgently needs to be solved. Summary of the Invention
[0004] The purpose of this application is to provide an energy storage converter and control method, thereby quickly releasing the electrical energy of the bus capacitor module and improving the safety of the entire energy storage converter.
[0005] To address the aforementioned technical problems, embodiments of this application provide an energy storage converter, comprising: a discharge control unit, an energy conversion unit, an energy discharge unit, a first power switching device, a bus capacitor module, and a converter power module; a first terminal of the energy conversion unit is connected to the energy discharge unit, a second terminal of the energy conversion unit is connected to the first terminal of the first power switching device, and a second terminal of the first power switching device is connected to the bus capacitor module; the bus capacitor module is also connected to the converter power module; a first control terminal of the discharge control unit is connected to the control terminal of the first power switching device; the converter power module is used to convert an input DC voltage into an AC voltage; the discharge control unit is used to control the first power switching device to turn off when the converter power module is operating, and to control the first power switching device to turn on when the converter power module stops operating; the energy conversion unit is used to receive the bus voltage of the bus capacitor module when the first power switching device is on, and to convert the bus voltage into a supply voltage; the energy discharge unit is used to discharge the electrical energy of the bus capacitor module according to the supply voltage.
[0006] An embodiment of this application also provides a control method for an energy storage converter, applied to the discharge control unit in the energy storage converter; the control method for the energy storage converter includes: acquiring the operating state of the converter power module; controlling the first power switching device to turn off when the converter power module is operating; and controlling the first power switching device to turn on when the converter power module stops operating.
[0007] An embodiment of this application also provides a control method for an energy storage converter, applied to a BMS unit in the energy storage converter; the control method for the energy storage converter includes: acquiring the operating state of the converter power module; when the converter power module is operating, controlling the second power switching device to turn on and the third power switching device to turn off; when the converter power module stops operating, controlling the second power switching device to turn off and the third power switching device to turn on.
[0008] In some embodiments, the second control terminal of the discharge control unit is connected to the energy conversion unit; the discharge control unit is used to acquire the voltage value of the bus voltage received by the energy conversion unit from the bus capacitor module after the first power switching device is turned on, and adjust the voltage conversion ratio of the energy conversion unit according to the voltage value of the bus voltage.
[0009] In some embodiments, the energy conversion unit includes a primary coil and a secondary coil; the two ends of the primary coil are connected to the bus capacitor module; the two ends of the secondary coil are connected to the energy discharge unit; the primary coil has an adjustable terminal; the voltage conversion ratio is the ratio between the number of primary coils used for voltage conversion and the number of secondary coils; the discharge control unit is used to gradually reduce the number of primary coils used for voltage conversion through the adjustable terminal according to the voltage value of the bus voltage after controlling the first power switching device to turn on.
[0010] In some embodiments, the first power supply terminal of the discharge control unit is connected to a power supply; the second power supply terminal of the discharge control unit is connected to the energy conversion unit; the discharge control unit is further configured to obtain electrical energy from the power supply through the first power supply terminal when the first power switching device is turned off; the discharge control unit is further configured to obtain electrical energy from the bus capacitor module through the second power supply terminal when the first power switching device is turned on.
[0011] In some embodiments, the energy discharge unit includes: a first switch module, a second switch module, a third switch module, and a resistor module; a first terminal of the first switch module is connected to a first terminal of the energy conversion unit, and a second terminal of the first switch module is connected to the resistor module; a control terminal of the first switch module is connected to a first terminal of the second switch module, a second terminal of the second switch module is grounded, and a control terminal of the second switch module is connected to the BMS unit; a first terminal of the third switch module is connected to the second power switching device, a second terminal of the third switch module is grounded, and a control terminal of the third switch module is connected to the BMS unit. In some embodiments, the energy storage converter further includes a BMS unit, a second power switching device, and a third power switching device; the energy discharge unit is connected to the first terminal of the converter power module through the second power switching device; the third power switching device is disposed between the energy conversion unit and the energy discharge unit; the BMS unit is connected to the control terminal of the second power switching device and the control terminal of the third power switching device respectively; the BMS unit is used to control the second power switching device to turn on and the third power switching device to turn off when the converter power module is working, and the energy discharge unit is also used to discharge the peak voltage at the first terminal of the converter power module; the BMS unit is also used to control the second power switching device to turn off and the third power switching device to turn on when the converter power module stops working; the energy conversion unit is used to receive the bus voltage of the bus capacitor module and convert the bus voltage into a supply voltage when the first power switching device is on, the second power switching device is off, and the third power switching device is on.
[0012] The technical solution provided in this application has at least the following advantages:
[0013] In this embodiment, the energy storage converter includes a discharge control unit, an energy conversion unit, an energy discharge unit, and a first power switch. When the converter power module is operating, the discharge control unit controls the first power switch to turn off, disconnecting the bus capacitor module from the energy conversion unit and the energy discharge unit, and the bus capacitor module is in a charging state. When the converter power module stops operating, the discharge control unit controls the first power switch to turn on, connecting the bus capacitor module to the energy conversion unit and the energy discharge unit, and the bus capacitor module is in a discharging state. Thus, when the first power switch is on, the energy conversion unit converts the bus voltage of the bus capacitor module into a supply voltage, allowing the energy discharge unit to discharge the energy of the bus capacitor module. This enables the energy discharge unit to quickly release the energy of the bus capacitor module, improving the safety of the entire energy storage converter. Attached Figure Description
[0014] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.
[0015] Figure 1 This is a schematic diagram of the structure of an energy storage converter according to an embodiment of this application;
[0016] Figure 2 This is a schematic diagram of the structure of an energy conversion unit according to an embodiment of this application;
[0017] Figure 3 This is a schematic diagram of the structure of an energy storage converter according to another embodiment of this application;
[0018] Figure 4 This is a schematic diagram of the specific circuit structure of an energy storage converter according to an embodiment of this application;
[0019] Figure 5 This is a schematic diagram of the specific circuit structure of an energy storage converter according to an embodiment of this application;
[0020] Figure 6 This is a schematic diagram of the specific circuit structure of an energy discharge unit according to an embodiment of this application;
[0021] Figure 7 This is a comparison diagram of the energy dissipation effect and the natural discharge effect of the bus capacitor diaphragm group according to an embodiment of this application;
[0022] Figure 8 This is a schematic diagram of the structure of a multi-dimensional IoT fusion control system according to an embodiment of this application;
[0023] Figure 9 This is a schematic diagram of the structure of a converter control module according to an embodiment of this application;
[0024] Figure 10 This is a schematic flowchart of a control method for an energy storage converter according to an embodiment of this application;
[0025] Figure 11 This is a schematic flowchart of a control method for an energy storage converter according to another embodiment of this application. Detailed Implementation
[0026] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the various embodiments of this application will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the various embodiments of this application to help readers better understand this application. However, the technical solutions claimed in this application can be implemented even without these technical details and various changes and modifications based on the following embodiments. The division of the various embodiments below is for the convenience of description and should not constitute any limitation on the specific implementation of this application. The various embodiments can be combined with and referenced by each other without contradiction.
[0027] One embodiment of this application relates to an energy storage converter, the specific structural schematic diagram of which is shown below. Figure 1 As shown, the energy storage converter includes: a discharge control unit 101, an energy conversion unit 102, an energy discharge unit 103, a first power switching device 1041, a bus capacitor module 105, and a converter power module 106.
[0028] Specifically, the first end of the energy conversion unit 102 is connected to the energy discharge unit 103, and the second end of the energy conversion unit 102 is connected to the first end of the first power switching device 1041. The second end of the first power switching device 1041 is connected to the bus capacitor module 105. The bus capacitor module 105 is also connected to the converter power module 106. The first control end of the discharge control unit 101 is connected to the control end of the first power switching device 1041. The converter power module 106 is used to convert the input DC voltage into AC voltage. The discharge control unit 101 is used to control the first power switching device 1041 to turn off when the converter power module 106 is working, and to control the first power switching device 1041 to turn on when the converter power module 106 stops working. The energy conversion unit 102 is used to receive the bus voltage of the bus capacitor module 105 and convert the bus voltage into the supply voltage when the first power switching device 1041 is on. The energy discharge unit 103 is used to discharge the electrical energy of the bus capacitor module 105 according to the supply voltage.
[0029] Specifically, the converter power module 106 is the core component for the operation of the energy storage converter. The converter power module 106 includes multiple switching transistors, such as IGBT electronic switches. By turning on and off multiple switching transistors, the DC voltage is converted into AC voltage. The first terminal of the converter power module 106 is the DC side, and the second terminal of the converter power module 106 is the AC side.
[0030] When the converter power module 106 stops working, the AC side of the converter power module 106 is de-energized. The bus capacitor module 105 still retains high voltage and residual energy. If this residual energy is not discharged in time, it can generate electrical sparks and even pose an explosion risk, causing electric shock to maintenance and repair personnel. Because traditional high-voltage, large-capacity bus capacitors can have a discharge time of up to one hour or even longer, active or passive discharge measures are needed to release the residual energy of the capacitors and ensure the absolute electrical safety of the energy storage converter. This embodiment can effectively release the residual energy of the bus capacitor module 105 of the energy storage converter in the event of an emergency power outage or after the equipment stops working, improving the safety and reliability of the energy storage converter, reducing costs and failure rates, and preventing personal injury.
[0031] In this embodiment, the energy storage converter includes a discharge control unit 101, an energy conversion unit 102, an energy discharge unit 103, and a first power switching device 1041. When the converter power module 106 is operating, the discharge control unit 101 controls the first power switching device 1041 to turn off, disconnecting the bus capacitor module 105 from the energy conversion unit 102 and the energy discharge unit 103, thus placing the bus capacitor module 105 in a charging state. When the converter power module 106 stops operating, the discharge control unit 101 controls the first power switching device 1041 to turn off. When the first power switching device 1041 is turned on, the bus capacitor module 105 is connected to the energy conversion unit 102 and the energy discharge unit 103. The bus capacitor module 105 is in a discharging state, so that when the first power switching device 1041 is turned on, the energy conversion unit 102 converts the bus voltage of the bus capacitor module 105 into the supply voltage, which is used by the energy discharge unit 103 to discharge the electrical energy of the bus capacitor module 105. Thus, the electrical energy of the bus capacitor module 105 is quickly released through the energy discharge unit 103, improving the safety of the entire energy storage converter.
[0032] Specifically, such as Figure 1As shown, the energy storage converter also includes a converter control module 107, and a discharge control unit 101 is also connected to the converter control module 107; the discharge control unit 101 is also used to obtain the operating status of the converter power module 106 through the converter control module 107. The converter control module 107 is used in the energy storage converter to control the operation and shutdown of the converter power module 106, that is, to control the on and off of the switching transistors in the converter power module 106. Therefore, the converter control module 107 can obtain the operating status of the converter power module 106. The converter power module 106 sends its operating status to the discharge control unit 101. The discharge control unit 101 controls the on and off of the first power switching device 1041 according to the operating status of the converter power module 106. Thus, when the first power switching device 1041 is on, the energy of the bus capacitor module 105 is quickly released through the energy discharge unit 103, thereby improving the safety of the entire energy storage converter.
[0033] In one embodiment, such as Figure 1 As shown, the second control terminal of the discharge control unit 101 is connected to the energy conversion unit 102, forming a control loop between the discharge control unit 101 and the energy conversion unit 102. The discharge control unit 101 is used to obtain the voltage value of the bus voltage received by the energy conversion unit 102 from the bus capacitor module 105 after the first power switching device 1041 is turned on, and adjust the voltage conversion ratio of the energy conversion unit 102 according to the voltage value of the bus voltage.
[0034] As the bus capacitor module 105 continuously releases electricity, the output bus voltage of the bus capacitor module 105 continuously decreases. If a fixed voltage conversion ratio is used, the supply voltage of the energy discharge unit 103 also continuously decreases, thereby reducing the efficiency of the energy discharge unit 103 in discharging the residual electricity from the bus capacitor module 105. Therefore, in order to improve the discharge efficiency of the bus capacitor module 105, the discharge control unit 101 of this embodiment controls the voltage conversion ratio of the energy conversion unit 102 according to the residual circuit of the bus capacitor module 105. This allows for more precise control of the supply voltage of the energy discharge unit 103, ensuring that the supply voltage of the energy discharge unit 103 is in a stable and more energy-efficient state, thus improving the discharge efficiency of the residual electricity from the bus capacitor module 105.
[0035] Specifically, such as Figure 2The diagram shows the structure of the energy conversion unit in this embodiment. The energy conversion unit 102 includes a primary coil 1021 and a secondary coil 1022. The two ends of the primary coil 1021 are connected to the bus capacitor module 105. The two ends of the secondary coil 1022 are connected to the energy discharge unit 103. The primary coil 1021 has an adjustable terminal 1026. The voltage conversion ratio is the ratio between the number of primary coils 1021 used for voltage conversion and the number of secondary coils 1022. The discharge control unit 101 is used to gradually reduce the number of primary coils 1021 used for voltage conversion through the adjustable terminal 1026 according to the voltage value of the bus voltage after the first power switching device 1041 is turned on.
[0036] Specifically, the energy conversion unit 102 also includes a primary side terminal 1023, a secondary side terminal 1024, and an iron core 1025. The primary side coil 1021 and the secondary side coil 1022 are both wound on the iron core 1025. The primary side terminal 1023 corresponds to the primary side coil 1021 and is used to connect to the bus capacitor module 105. The secondary side terminal 1024 corresponds to the secondary side coil 1022 and is used to connect to the energy discharge unit 103.
[0037] In this embodiment, an adjustable terminal 1026 is provided on the primary coil 1021. As the bus capacitor module 105 continuously releases electricity, the output bus voltage of the bus capacitor module 105 continuously decreases. Therefore, in order to improve the discharge efficiency of the bus capacitor module 105, this embodiment controls the sliding of the adjustable terminal 1026 to gradually reduce the number of primary coils 1021 used for voltage conversion. That is, the voltage conversion ratio also continuously decreases. This ensures that the power supply voltage of the control energy discharge unit 103 is in a stable and more efficient energy consumption state. In other words, the control energy discharge unit 103 can stably and effectively discharge the electricity of the bus capacitor module 105, thereby improving the discharge efficiency of the residual electricity of the bus capacitor module 105.
[0038] In this embodiment, the discharge control unit 101 is used to obtain the remaining residual energy of the bus capacitor module 105 after power failure through the energy conversion unit 102, and adjust it in a timely manner according to the change of the residual voltage of the bus capacitor. The output voltage is obtained through the energy conversion unit 102 and given to the energy discharge unit 103 to carry out the active energy consumption process, thereby discharging energy.
[0039] In one embodiment, the first power supply terminal of the discharge control unit 101 is connected to a power supply; the discharge control unit 101 is powered by the power supply; further, the second power supply terminal of the discharge control unit 101 is connected to an energy conversion unit; such as Figure 3The diagram shown is a structural schematic of the energy storage converter in this embodiment. The first power supply terminal of the discharge control unit 101 is connected to the power supply 108. The discharge control unit 101 is powered by the power supply 108. The second power supply terminal of the discharge control unit 101 is connected to the energy conversion unit 102, forming a power supply loop between the discharge control unit 101 and the energy conversion unit 102. The discharge control unit 101 and the energy conversion unit 102 also have a control loop.
[0040] Specifically, the discharge control unit 101 is also used to obtain electrical energy from the power supply 108 through the first power supply terminal when the first power switching device 1041 is turned off; the discharge control unit 101 is also used to obtain electrical energy from the bus capacitor module 105 through the energy conversion unit 102 through the second power supply terminal when the first power switching device 1041 is turned on.
[0041] Specifically, when the converter power module 106 is operating, the bus capacitor module 105 is in a charging state, and the discharge control unit 101 is powered by the power supply 108, meaning the discharge control unit 101 obtains power from the power supply 108 through the first power supply terminal. When the converter power module 106 is not operating, the bus capacitor module 105 can discharge energy not only through the energy discharge unit 103 but also through the discharge control unit 101, meaning the discharge control unit 101 obtains power from the bus capacitor module 105 through the second power supply terminal, which can further improve the discharge efficiency of the bus capacitor module 105. Simultaneously, the discharge control unit 101 can obtain power from both the power supply 108 and the bus capacitor module 105, effectively providing the discharge control unit 101 with another power source. This reduces the energy consumption of the original power supply 108, extends the power supply time of the power supply 108, and improves the operating efficiency of the energy storage converter.
[0042] Specifically, in this embodiment, after the power of the bus capacitor bank is completely discharged, no power is supplied to the discharge control unit 101 through the second power supply terminal, and the discharge control unit 101 stops working. At this time, the working status of the discharge control unit 101 can be used to determine whether the power of the bus capacitor bank is completely discharged. The working status of the discharge control unit 101 can be determined by connecting the discharge control unit 101 through the BMS unit. When the discharge control unit 101 stops working, it is determined that the power of the bus capacitor bank is completely discharged, which can remind maintenance personnel. Only after receiving the notification that the power of the bus capacitor bank is completely discharged can the maintenance personnel perform maintenance operations on the energy storage converter, thereby improving the safety of the energy storage converter during the maintenance process.
[0043] like Figure 4The diagram shows the specific circuit structure of the energy storage converter in this embodiment. The bus capacitor module 105 consists of multiple bus electrolytic capacitors 1051, the energy conversion unit 102 consists of a transformer, and the first power switching device 1041 is a switch, such as an IGBT (Insulated Gate Bipolar Transistor) or a transistor. The discharge control unit 101 internally houses a microcontroller unit (MCU), i.e., the MCU master controller 1011. When the converter power module 106 is operating normally, the bus capacitor module 105 is in a charging state to continuously support the operation of the converter power module 106. Therefore, the MCU master controller 1011 drives the first power switching device 1041 to keep its main contacts in a normally open state, effectively disconnecting the energy conversion unit from the bus capacitor module 105, forming a clear disconnection point, and preventing energy from being discharged. When the converter power module 106 stops, the MCU main controller 1011 drives the first power switching device 1041 to change its main contacts from normally open to normally closed, forming a discharge circuit between the energy conversion unit and the bus capacitor module 105, and starting the subsequent circuit to discharge energy. The MCU main controller 1011's drive signal is controlled by the converter control module 107, and it makes logical judgments based on the signals sent by the converter control module 107, i.e., the real-time operating status of the converter power module 106.
[0044] In one embodiment, the energy storage converter further includes a battery management unit (BMS), a second power switching device, and a third power switching device; such as Figure 5 The diagram shown is a schematic diagram of the specific circuit structure of the energy storage converter in this embodiment. The energy storage converter in this embodiment also includes a battery management unit 110, a second power switching device 1042, and a third power switching device 1043.
[0045] Specifically, the energy discharge unit 103 is connected to the first terminal of the inverter power module 106 via the second power switch device 1042; the third power switch device 1043 is disposed between the energy conversion unit 102 and the energy discharge unit 103; the battery management unit 110 is connected to the control terminals of the second power switch device 1042 and the third power switch device 1043 respectively; the battery management unit 110 is used to control the second power switch device 1042 to be turned on and the third power switch device 1043 to be turned off when the inverter power module 106 is working. The energy discharge unit 103 is also used to discharge the peak voltage at the first end of the inverter power module 106; the battery management unit 110 is also used to control the second power switch device 1042 to turn off and the third power switch device 1043 to turn on when the inverter power module 106 stops working; the energy conversion unit 102 is used to receive the bus voltage of the bus capacitor module 105 and convert the bus voltage into the supply voltage when the first power switch device 1041 is on, the second power switch device 1042 is off, and the third power switch device 1043 is on.
[0046] To prevent damage to the equipment caused by the DC-side peak voltage of the converter power module 106 directly acting on the bus capacitor module 105, this embodiment introduces a pre-charge circuit, namely the energy discharge unit 103 and the second power switching device 1042. The pre-charge circuit can first pass the voltage on the DC side of the converter power module 106 through the energy discharge unit 103 to consume a portion of the DC port voltage, so as to control the DC port energy to be supplied to the bus capacitor module 105 in a slow ramp-up manner, so as to reach the maximum value in a gradual energy rise manner, thereby preventing insulation damage.
[0047] In this embodiment, the energy storage converter operates under two energy discharge conditions: condition a and condition b. In condition a, when the 1500V high-voltage DC side soft-start function inside the high-voltage box of the energy storage converter is activated, the DC side peak voltage directly acts on the bus capacitor module 105, potentially causing equipment damage. Therefore, this embodiment introduces a pre-charge circuit, requiring the energy discharge unit 103 to absorb some energy to satisfy the high-voltage soft-start circuit and slowly charge the bus capacitor. In condition b, when the energy storage converter is in shutdown or maintenance mode, residual energy remains in its capacitors after power failure. Adjustments need to be made based on changes in the residual voltage of the bus capacitor. Therefore, this embodiment utilizes the aforementioned energy storage converter structure to achieve energy conversion, control, and discharge processes, thus performing an active energy consumption process, i.e., energy discharge.
[0048] In this embodiment, the battery management unit 110, or BMS unit, controls the second power switch device 1042 and the third power switch device 1043 to turn on and turn off the third power switch device 1043 when the inverter power module 106 is operating, so that the energy discharge unit 103 discharges the peak voltage at the first terminal (DC side) of the inverter power module 106. When the inverter power module 106 is not operating, the BMS unit controls the second power switch device 1042 to turn off and the third power switch device 1043 to turn on, so that the energy discharge unit 103 discharges the electrical energy of the bus capacitor module 105. At the same time, the energy discharge unit 103 also has the function of discharging the electrical energy of the bus capacitor module 105. The energy discharge unit 103 integrates two functions, which can reduce material costs and space costs. In addition, since the second power switch and the third power switch device 1043 are in opposite states and are both controlled by the BMS unit, the accuracy of control can be improved, avoiding the simultaneous conduction of the second power switch and the third power switch device 1043, which could lead to device malfunction and cause unnecessary hidden dangers. Malfunctions can result in explosions and shutdowns, posing safety hazards. Therefore, this embodiment improves the accuracy of control in this way, thereby enhancing the safety of the energy storage converter.
[0049] That is, this embodiment also saves the structural space occupied by the braking resistor and the unstable temperature rise of the high-voltage box caused by the heating of the braking resistor in the conventional solution; and the energy discharge unit 103 in this embodiment achieves the technical effect of both, and can play a role in terms of structural space, material cost and temperature rise effect, which is conducive to improving the energy density and working efficiency of the equipment; in addition, the energy discharge unit 103 in this embodiment integrates algorithm control, which can effectively control the discharge time and discharge depth, ensuring the high reliability of energy discharge and ensuring electrical safety.
[0050] Specifically, the energy storage converter also includes a converter control module 107, and the battery management unit 110 is also connected to the converter control module 107; the battery management unit 110 is also used to obtain the operating status of the converter power module 106 through the converter control module 107.
[0051] Specifically, in this embodiment, the DC side of the converter control module 107 is a DC input bus. A fourth power switch device 1044 is installed on the DC input bus. When the fourth power switch device 1044 is turned on, a DC voltage is input to the DC side of the converter control module 107, and the converter control module 107 starts to work. When the fourth power switch device 1044 is turned off, there is no DC voltage on the DC side of the converter control module 107, and the converter control module 107 stops operating. In this embodiment, the converter power module 106 is a converter power board. The output terminal of the converter power module 106 is connected to the converter AC output board 1061, and the converter AC output board 1061 has multiple switches installed inside.
[0052] Specifically, such as Figure 6 The diagram shown is a circuit structure schematic of the energy discharge unit in this embodiment. The energy discharge unit 103 in this embodiment includes: a first switch module 1031, a second switch module 1032, a third switch module 1033, and a resistor module 1034. The first terminal of the first switch module 1031 is connected to the first terminal of the energy conversion unit 102, and the second terminal of the first switch module 1031 is connected to the resistor module 1034. The control terminal of the first switch module 1031 is connected to the first terminal of the second switch module 1032, the second terminal of the second switch module 1032 is grounded, and the control terminal of the second switch module 1032 is connected to the BMS unit. The first terminal of the third switch module 1033 is connected to the second power switching device 1042, the second terminal of the third switch module 1033 is grounded, and the control terminal of the third switch module 1033 is connected to the BMS unit.
[0053] Figure 6 In the diagram, bus capacitor + and bus capacitor - represent the first receiving end of energy discharge unit 103, which is used to connect to the first end of energy conversion unit 102. Bus capacitor + and bus capacitor - are both connected to resistor module 1034 through a first switch module 1031. Figure 6 In the diagram, DC bus + and DC bus - represent the second receiving terminals of the energy dissipation unit 103, which are used to connect to the second power switching device 1042. Both DC bus + and DC bus - are connected to the resistor module 1034 through a third switching module.
[0054] When the energy discharge unit 103 needs to discharge the electrical energy of the bus capacitor module 105, the BMS unit controls the first switch module 1031 to be turned on through the control terminal of the first switch module 1031. At this time, the third switch module 1033 is turned off, and the electrical energy of the bus capacitor module 105 is transferred to the resistor module 1034 through the bus capacitor + and bus capacitor -. The resistor module 1034 consumes electrical energy when it works. When the energy discharge unit 103 needs to discharge the peak voltage of the first terminal of the converter power module, the BMS unit controls the third switch module 1033 to be turned on through the control terminal of the third switch module 1033. At this time, the first switch module 1031 is turned off, and the peak voltage of the first terminal of the converter power module is transferred to the resistor module 1034 through the DC bus + and DC bus -. The resistor module 1034 consumes electrical energy when it works. Specifically, when the BMS unit needs to control the first switch module 1031 to be turned on, it sends a bus capacitor discharge control signal; when the BMS unit needs to control the third switch module 1033 to be turned on, it sends a DC bus discharge control signal.
[0055] During the operation of resistor module 1034, when the voltage suddenly increases, the current also increases. The discharge resistor limits the current through its resistance value, keeping the voltage in the circuit within a safe range and preventing damage due to excessive current. According to Ohm's law, the resistance value R is equal to the ratio of voltage V to current I, i.e., R = V / I. When current flows through resistor module 1034, the voltage drop generated by the resistor will limit the current flow. According to Joule's law, heat is generated when current flows through resistor module 1034, and its magnitude is proportional to the square of current I, i.e., P = I²R. Therefore, when current flows through resistor module 1034, resistor module 1034 will generate heat due to energy dissipation. Therefore, this embodiment also includes a heat dissipation module to absorb heat and achieve energy dissipation and conversion functions.
[0056] The resistor module 1034 is composed of multiple resistors R0 connected in series. The resistance value of each resistor R0 can be 10KΩ. By using multiple small resistors R0 connected in series, the resistance value of the resistor module 1034 is relatively large, which can discharge more electrical energy. At the same time, if a large resistor is used, the size of the resistor module 1034 will be large and the cost will be high. Therefore, by using multiple small resistors R0 connected in series, the size of the energy storage converter can also be reduced and the cost of the energy storage converter can be saved.
[0057] like Figure 6As shown, the first switch module 1031 of this embodiment includes: a magnet YA and an electromagnetic switch S disposed opposite to the magnet YA; a diode D is also connected to both ends of the magnet YA, namely pin 1 and pin 8. The anode of the diode D is connected to the collector of the transistor and the first end of the magnet YA, and the cathode of the diode D is connected to the second end of the magnet YA. The second end of the magnet YA is also connected to a power supply with a voltage of 5V. In this embodiment, the second switch module 1032 is a transistor Q. The base of transistor Q is connected to the BMS unit, specifically through a resistor R3, thereby improving the stability of the received signal. The collector of transistor Q is connected to the control terminal of the first switch module 1031, and the emitter of transistor Q is grounded. When the base of transistor Q receives the bus capacitor discharge control signal, the transistor is turned on, the magnet YA is energized, and the electromagnetic switch S is closed. That is, pins 6 and 7 of the electromagnetic switch S are connected, and pins 3 and 2 are connected, causing the resistor module 1034 to conduct and begin discharging energy. When the base of transistor Q does not receive the bus capacitor discharge control signal, the transistor is turned off, the magnet YA is not energized, and the electromagnetic switch S is opened. That is, pins 6 and 4 of the electromagnetic switch S are connected, and pins 6 and 5 are connected, and the resistor module 1034 does not work.
[0058] like Figure 6 As shown, the energy discharge unit 103 in this embodiment further includes: a voltage regulator module, specifically a voltage regulator resistor R1. The voltage regulator resistor R1 is connected between the base and emitter of the transistor Q to stabilize the bus capacitor discharge control signal input to the BMS unit and improve signal stability. A first filter capacitor C1 is also connected in parallel across the voltage regulator resistor R1 to filter the signal and improve signal accuracy.
[0059] like Figure 6 As shown, the third switching module 1033 is a MOSFET M. The gate of MOSFET M is used to receive the DC bus discharge control signal output by the BMS unit. When the gate of MOSFET M receives the DC bus discharge control signal, MOSFET M is turned on, and resistor module 1034 starts to work to discharge energy. When the gate of MOSFET M does not receive the DC bus discharge control signal, MOSFET M is turned off, and resistor module 1034 does not work to discharge. The source of MOSFET M is connected to resistor module 1034, and the drain of MOSFET is connected to second power switching device 1042. In this embodiment, the source of MOSFET M is also grounded through resistor R2. The energy discharge unit 103 also includes a second filter capacitor C2. The second filter capacitor C2 is set across resistor R2 to perform filtering and improve voltage accuracy.
[0060] As can be seen, the energy discharge unit 103 also performs the soft-start function of the 1500V high-voltage DC side inside the high-voltage box. Through a logic circuit control unit, the high-voltage box and the PCS share a single discharge unit, achieving dual functionality. This achieves rapid discharge while reducing structural installation space, thus lowering costs and increasing efficiency. Simultaneously, the logic circuit controls the heat dissipation module to achieve rapid heat dissipation of the energy-to-heat conversion module, solving the problem of the discharge unit's temperature rising rapidly and burning out the circuit.
[0061] like Figure 7 The figure shows a comparison between the energy discharge effect and the natural discharge effect of the bus capacitor membrane group in this embodiment. The horizontal axis represents time and the vertical axis represents energy. It can be seen that when the bus capacitor membrane group has the same energy, that is, the charge is 100%, the curve of natural discharge decreases more slowly, and it takes about 10.5 minutes for the bus voltage to drop to 0. In contrast, the discharge curve of this embodiment decreases more quickly, and the discharge time is about 3.5 minutes. The discharge time of this embodiment is significantly reduced compared with the time of natural discharge, and the discharge efficiency is significantly improved.
[0062] In this embodiment, a discharge control unit 101 is added. The discharge control unit 101 mainly consists of a microcontroller unit (MCU main controller), a power supply circuit, a control circuit, an output circuit, and a feedback circuit. It is used to issue and terminate the discharge signal. It also carries the control function of the PCS (Power Conversion System, energy storage converter) main controller, i.e., the converter control module's high-voltage circuit soft start signal, realizing the control function of one MCU main controller for multiple terminal devices. At the same time, it communicates with the high-voltage box BMS unit through its bus protocol to realize multi-dimensional IoT fusion control function, so as to further improve the high reliability of the control system.
[0063] like Figure 8The diagram shown is a structural schematic of the multi-dimensional IoT fusion control system 10 of this embodiment. The multi-dimensional IoT fusion control system 10 includes: a data storage unit 112, a data processing unit 113, a microcontroller unit 111 (MCU main controller), a converter control module 107 (PCS unit), and an energy management unit 109 (EMS). The system (energy management system) unit, battery management unit 110 (BMS unit), and data storage unit 111 store computer programs that can run on the data processing unit. The MCU main controller and PCS unit are integrated together. The multi-dimensional IoT fusion control system is powered by the power module 116 and obtains various operating parameters of the energy storage converter through the sensor module 117. Among them, the MCU main controller assists the PCS algorithm in realizing multi-dimensional IoT fusion control of multiple units of the entire energy storage system through the input / output circuit module 114 (I / O (INPUT / Output) circuit module) and the bus communication module 115. Through the data fusion module 118, the data information of each independent unit of the EMS unit, BMS unit, and PCS unit is fused and processed to ensure efficient sharing of data link information between multiple units in the energy storage architecture, achieving a low-latency and high-reliability control method for the control software.
[0064] like Figure 9 The diagram shows the structure of the converter control module, where the converter control module 107, or PCS unit, includes: a digital signal processor 1071 (DSP), a field programmable gate array 1072 (FPGA), and an advanced RISC machine 1073 (ARM). The control part of the PCS unit adopts a DSP+FPGA+ARM main architecture. The power supply voltage 120V provides power to the PCS unit. The DSP and FPGA exchange data through the data interaction unit 119, which performs control mode selection and control parameter processing, realizes control algorithm fusion technology, fault protection, and data uploading to the host computer, effectively ensuring the safety and high reliability of the control system.
[0065] Another aspect of this application embodiment provides a control method for an energy storage converter, applied to the discharge control unit in the energy storage converter of the above embodiment, such as... Figure 10 The diagram shown is a flowchart illustrating the control method for the energy storage converter in this embodiment. The control method for the energy storage converter in this embodiment includes the following steps:
[0066] Step 201: Obtain the operating status of the converter power module.
[0067] Step 202: When the converter power module is working, control the first power switching device to turn off.
[0068] Step 203: When the converter power module stops working, control the first power switching device to turn on.
[0069] In this embodiment, when the converter power module is operating, the discharge control unit controls the first power switch to turn off, disconnecting the bus capacitor module from the energy conversion unit and the energy discharge unit, and the bus capacitor module is in a charging state. When the converter power module stops operating, the discharge control unit controls the first power switch to turn on, connecting the bus capacitor module to the energy conversion unit and the energy discharge unit, and the bus capacitor module is in a discharging state. Thus, when the first power switch is on, the energy conversion unit converts the bus voltage of the bus capacitor module into a supply voltage, allowing the energy discharge unit to discharge the electrical energy of the bus capacitor module. This enables the energy discharge unit to quickly release the electrical energy of the bus capacitor module, improving the safety of the entire energy storage converter.
[0070] In this embodiment, the second control terminal of the discharge control unit is connected to the energy conversion unit; such as... Figure 10 As shown, after controlling the first power switching device to turn on, the discharge control unit of this embodiment further includes the following steps:
[0071] Step 204: Obtain the voltage value of the bus voltage received by the energy conversion unit from the bus capacitor module.
[0072] Step 205: Adjust the voltage conversion ratio of the energy conversion unit according to the bus voltage value.
[0073] In order to improve the discharge efficiency of the bus capacitor module, the discharge control unit of this embodiment controls the voltage conversion ratio of the energy conversion unit according to the residual circuit of the bus capacitor module. This allows for more precise control of the power supply voltage of the energy discharge unit, ensuring that the power supply voltage of the energy discharge unit is in a stable and more efficient energy-consuming state, thereby improving the discharge efficiency of the residual charge of the bus capacitor module.
[0074] In this embodiment, the first power supply terminal of the discharge control unit is connected to the power supply, and the second power supply terminal of the discharge control unit is connected to the energy conversion unit. The control method of the energy storage converter in this embodiment further includes: when the first power switching device is turned off, obtaining the power supply through the first power supply terminal; when the first power switching device is turned on, obtaining the power of the bus capacitor module from the energy conversion unit through the second power supply terminal.
[0075] Specifically, in this embodiment, when the converter power module stops working, the residual energy of the bus capacitor module exhibits a discharge phenomenon from high to low. The energy conversion unit acquires the residual energy and converts it into a corresponding voltage, adjusting it in a timely manner according to the change in the bus residual voltage. After acquiring the bus voltage, the discharge control unit activates the MCU startup algorithm program embedded in the discharge control unit and starts running, controlling the energy conversion unit to discharge energy, thus discharging the residual energy. When the output voltage of the bus capacitor module has not decreased to 0V, the energy conversion unit continues to perform energy conversion, and the discharge control unit continues to work. When the output voltage of the bus capacitor module decreases to 0V, the energy conversion unit can no longer perform energy conversion, the second power supply terminal of the discharge control unit loses power, and at this time the converter power module stops working, and both the first and second power supply terminals of the discharge control unit lose power, causing the discharge control unit to stop working, and the discharge of residual energy ends.
[0076] It is not difficult to see that this embodiment is a method embodiment corresponding to the above structural embodiment, and this embodiment can be implemented in conjunction with the structural embodiment. The relevant technical details mentioned in the structural embodiment are still valid in this embodiment, and will not be repeated here to reduce repetition. Correspondingly, the relevant technical details mentioned in this embodiment can also be applied to the structural embodiment.
[0077] Another aspect of this application embodiment provides a control method for an energy storage converter, applied to the BMS unit in the energy storage converter of the above embodiment, such as... Figure 11 The diagram shown is a flowchart illustrating the control method for the energy storage converter in this embodiment. The control method for the energy storage converter in this embodiment includes the following steps:
[0078] Step 301: Obtain the operating status of the converter power module.
[0079] Step 302: When the converter power module is working, control the second power switch to turn on and the third power switch to turn off.
[0080] Step 303: When the converter power module stops working, control the second power switch device to turn off and the third power switch device to turn on.
[0081] In this embodiment, when the converter power module is working, the BMS unit controls the second power switch to be turned on and the third power switch to be turned off, so that the energy discharge unit discharges the peak voltage at the first terminal of the converter power module, i.e., the DC side; when the converter power module stops working, the BMS unit controls the second power switch to be turned off and the third power switch to be turned on, so that the energy discharge unit discharges the electrical energy of the bus capacitor module.
[0082] It is not difficult to see that this embodiment is a method embodiment corresponding to the above structural embodiment, and this embodiment can be implemented in conjunction with the structural embodiment. The relevant technical details mentioned in the structural embodiment are still valid in this embodiment, and will not be repeated here to reduce repetition. Correspondingly, the relevant technical details mentioned in this embodiment can also be applied to the structural embodiment.
[0083] Those skilled in the art will understand that the above embodiments are specific embodiments for implementing this application, and in practical applications, various changes can be made to them in form and detail without departing from the spirit and scope of this application.
Claims
1. An energy storage converter, characterized in that, include: Discharge control unit, energy conversion unit, energy discharge unit, first power switching device, bus capacitor module, converter power module; The first end of the energy conversion unit is connected to the energy discharge unit, the second end of the energy conversion unit is connected to the first end of the first power switching device, and the second end of the first power switching device is connected to the bus capacitor module; the bus capacitor module is also connected to the converter power module; the first control end of the discharge control unit is connected to the control end of the first power switching device. The converter power module is used to convert the input DC voltage into AC voltage; the discharge control unit is used to control the first power switching device to turn off when the converter power module is working, and to control the first power switching device to turn on when the converter power module stops working. The energy conversion unit is used to receive the bus voltage of the bus capacitor module when the first power switching device is turned on, and convert the bus voltage into a supply voltage; the energy discharge unit is used to discharge the electrical energy of the bus capacitor module according to the supply voltage. The second control terminal of the discharge control unit is connected to the energy conversion unit; The discharge control unit is used to acquire the voltage value of the bus voltage received by the energy conversion unit from the bus capacitor module after the first power switching device is turned on, and adjust the voltage conversion ratio of the energy conversion unit according to the voltage value of the bus voltage.
2. The energy storage converter according to claim 1, characterized in that, The energy conversion unit includes a primary coil and a secondary coil; The two ends of the primary coil are connected to the bus capacitor module; the two ends of the secondary coil are connected to the energy discharge unit; the primary coil has an adjustable end; the voltage conversion ratio is the ratio between the number of primary coils used for voltage conversion and the number of secondary coils; The discharge control unit is used to gradually reduce the number of primary coils used for voltage conversion through the adjustable terminal according to the voltage value of the bus voltage after controlling the first power switching device to turn on.
3. The energy storage converter according to claim 1, characterized in that, The first power supply terminal of the discharge control unit is connected to a power supply; the second power supply terminal of the discharge control unit is connected to the energy conversion unit. The discharge control unit is also used to obtain electrical energy from the power supply through the first power supply terminal when the first power switching device is turned off. The discharge control unit is also used to obtain electrical energy from the bus capacitor module through the second power supply terminal when the first power switching device is turned on.
4. The energy storage converter according to any one of claims 1 to 3, characterized in that, The energy storage converter also includes a BMS unit, a second power switching device, and a third power switching device; The energy discharge unit is connected to the first terminal of the converter power module through the second power switching device; the third power switching device is disposed between the energy conversion unit and the energy discharge unit; the BMS unit is connected to the control terminal of the second power switching device and the control terminal of the third power switching device respectively; The BMS unit is used to control the second power switching device to turn on and the third power switching device to turn off when the converter power module is working. The energy discharge unit is also used to discharge the peak voltage at the first terminal of the converter power module. The BMS unit is also used to control the second power switching device to turn off and the third power switching device to turn on when the converter power module stops working. The energy conversion unit is used to receive the bus voltage of the bus capacitor module and convert the bus voltage into a supply voltage when the first power switch is turned on, the second power switch is turned off, and the third power switch is turned on.
5. The energy storage converter according to claim 4, characterized in that, The energy dissipation unit includes: a first switch module, a second switch module, a third switch module, and a resistor module; The first terminal of the first switch module is connected to the first terminal of the energy conversion unit, and the second terminal of the first switch module is connected to the resistor module; the control terminal of the first switch module is connected to the first terminal of the second switch module, the second terminal of the second switch module is grounded, and the control terminal of the second switch module is connected to the BMS unit. The first terminal of the third switch module is connected to the second power switch device, the second terminal of the third switch module is grounded, and the control terminal of the third switch module is connected to the BMS unit.
6. A control method for an energy storage converter, characterized in that, The discharge control unit is applied in the energy storage converter according to claim 1; the control method of the energy storage converter includes: Obtain the operating status of the converter power module; When the converter power module is working, control the first power switching device to turn off; When the power module of the converter stops working, the first power switching device is turned on. The second control terminal of the discharge control unit is connected to the energy conversion unit; after the first power switching device is turned on, the system further includes: The voltage value of the bus voltage received by the energy conversion unit from the bus capacitor module is obtained; The voltage conversion ratio of the energy conversion unit is adjusted according to the voltage value of the bus voltage.
7. The control method for the energy storage converter according to claim 6, characterized in that, The first power supply terminal of the discharge control unit is connected to a power supply, and the second power supply terminal of the discharge control unit is connected to the energy conversion unit; the method further includes: When the first power switching device is turned off, the electrical energy of the power supply is obtained through the first power supply terminal; When the first power switching device is turned on, the electrical energy of the bus capacitor module is obtained from the energy conversion unit through the second power supply terminal.
8. A control method for an energy storage converter, characterized in that, The BMS unit applied in the energy storage converter according to claim 4 or 5; The control method for the energy storage converter includes: Obtain the operating status of the converter power module; When the converter power module is working, the second power switching device is turned on and the third power switching device is turned off. When the power module of the converter stops working, the second power switch is turned off and the third power switch is turned on.