Low-voltage multi-port single-phase power supply equipment

Abstract

The invention discloses low-voltage multi-port single-phase power supply equipment, which comprises an input unit, a central processing unit, an output unit, a communication unit and a man-machine interaction unit, and is characterized in that the input unit comprises a plurality of input ends which are independently controlled and are respectively adaptive to different types of electric energy access settings; the central processing unit comprises a central processing unit, a memory and a plurality of control logic modules, and the control logic modules comprise a three-phase imbalance control module, a harmonic suppression module, a voltage fluctuation and flicker suppression module, a voltage reactive power control module and a source network load storage coordinated optimization module. The output unit comprises a plurality of single-phase output ends which are independently controlled and are adaptive to different loads; according to the invention, various problems of low voltage qualified rate, large line loss, serious three-phase imbalance, limited distributed power supply bearing capability and load access capability and the like of the low-voltage power distribution network can be effectively solved, optimal control and stable power supply of the low-voltage power distribution network are realized, and flexible access and safe and high-quality power supply of local distributed source loads are realized.

Description

Technical Field

[0001] The invention belongs to the technical field of low-voltage power distribution networks, and in particular relates to a low-voltage multi-port single-phase power supply device. Background Art

[0002] With the continuous development of the economy and society and the green and low-carbon transformation, various new load equipment such as electric vehicles and various new distributed power sources such as photovoltaics and wind power have brought a series of power supply quality problems such as three-phase imbalance, voltage over-limit, high harmonic content, voltage fluctuation and flicker to the low-voltage distribution network; electric vehicles and other rural revitalization loads will usher in a faster growth, increasing the power balance pressure of the low-voltage distribution network, and the power supply and grid regulation capacity is limited. In addition, a large number of distributed power sources are connected to the low-voltage single-phase distribution network, making its three-phase imbalance, voltage over-limit, harmonics, voltage fluctuation and flicker and other power quality problems more prominent, seriously affecting the safe and high-quality power supply of the low-voltage distribution network, and it is urgent to further break through the low-voltage safe and high-quality power supply technology and distributed power consumption technology; the current three-phase imbalance of the low-voltage distribution network is mainly solved by phase-changing switches, but phase-changing switches can only partially solve the three-phase imbalance problem, and there are risks such as phase-to-phase short circuit and short-term power supply interruption; in order to solve the above problems, it is necessary to develop a low-voltage multi-port single-phase power supply device. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art and to provide a low-voltage multi-port single-phase power supply equipment with high safety and reliability, high efficiency, high flexibility and high economy, which can effectively solve various problems in the low-voltage distribution network, such as low voltage qualification rate, large line loss, serious three-phase imbalance, limited distributed power supply carrying capacity and load access capacity, etc., to achieve optimized control and stable power supply of the low-voltage distribution network, and realize flexible access of local distributed sources and loads and safe and high-quality power supply to local substations.

[0004] The object of the present invention is achieved as follows: A low-voltage multi-port single-phase power supply device comprises an input unit, a central processing unit, an output unit, a communication unit and a human-computer interaction unit; The input unit includes a plurality of input terminals which are independently controlled and respectively adapted to different types of electric energy access settings, the electric energy types include the upper power grid, the local distributed power source and the local energy storage system, and the distributed power source includes photovoltaic power generation and wind power; The central processing unit includes a central processing unit, a memory and a plurality of control logic modules. The central processing unit is the core processing unit of the device and is responsible for executing various control algorithms and data processing tasks. The memory is used to store the program code, data and parameters of the device. The control logic module includes a three-phase unbalanced control module, a harmonic control module, a voltage fluctuation and flicker suppression module, a voltage reactive power control module and a source-grid-load-storage coordination optimization module. The output unit includes a plurality of single-phase output terminals that are independently controlled and adapted to different loads. Different loads refer to loads with different voltage and current level requirements and / or different types of output ports, but all output ports shall comply with relevant safety standards and specifications; The communication unit is one or more of Ethernet, RS-485, CAN, and wireless communication technologies, and is used to realize the remote monitoring and operation functions of the equipment; The human-machine interaction unit includes a display screen and operation buttons, the display screen is used to display the operating status and parameters of the device, and the operation buttons are used for manual operation settings; The superior power grid, local distributed power sources and local energy storage systems are connected to the equipment through input units, and various loads are connected to the equipment through output units. The equipment works stably under the unified coordination of the central processing unit to provide safe and high-quality power supply for low-voltage users.

[0005] Preferably, the input end of the upper power grid is installed with a circuit breaker, a fuse, a lightning arrester and a power quality monitoring module, and the input end of the local distributed power supply and the local energy storage system is installed with a circuit breaker, a fuse, a lightning arrester, a power quality monitoring module and an AC-DC conversion device. The power quality monitoring module is used to monitor the voltage, current and frequency parameters of the input power supply in real time to provide data support for subsequent control.

[0006] Preferably, the single-phase output end is equipped with an overload protection device, a short-circuit protection device and an overheat protection device.

[0007] Preferably, the three-phase imbalance control module includes an intelligent switching switch or a dynamic reactive power compensation device, an intelligent algorithm and a current sensor installed on each phase. The central processing unit monitors the three-phase current size and phase difference collected by the current sensor in real time through the intelligent algorithm, and uses the intelligent switching switch or the dynamic reactive power compensation device to automatically adjust the load distribution to ensure that the imbalance of the three-phase current is within the allowable range.

[0008] Preferably, the harmonic control module adopts a harmonic filter, which is installed at key nodes to monitor the harmonic level in real time and dynamically adjust the filter parameters as needed to absorb or eliminate harmonics. The harmonic filter includes an active filter and / or a passive filter, and the key nodes are each input port, each load port, the common connection point on the load side, and the energy storage module.

[0009] Preferably, the voltage fluctuation and flicker suppression module adopts a dynamic voltage regulator or a static synchronous compensator, sets a reasonable response time and voltage range, monitors in real time, and quickly compensates for voltage fluctuations and flickers.

[0010] Preferably, the voltage reactive power control module uses a static reactive power generator or a static reactive power compensator and an intelligent controller to monitor load changes and grid demand in real time, and automatically adjust reactive power output to keep the power factor within a reasonable range.

[0011] Preferably, the source-grid-load-storage coordination optimization module adopts an integrated energy management system, which is used to achieve coordinated and optimized operation among the upper-level power grid, local distributed power sources, local energy storage systems and loads through output prediction of distributed power sources, load demand prediction and charge and discharge control of energy storage equipment.

[0012] Due to the adoption of the above technical scheme, the beneficial effects of the present invention are as follows: the present invention adopts a three-phase unbalanced control module, a harmonic control module, a voltage fluctuation and flicker suppression module, a voltage reactive power control module and a source-grid-load-storage coordinated optimization module, and each module works under the unified coordination of the central processor, which can effectively solve the various problems in the low-voltage distribution network, such as low voltage qualification rate, large line loss, serious three-phase imbalance, limited distributed power supply carrying capacity and load access capacity, etc., realize the optimized control and stable power supply of the low-voltage distribution network, realize the flexible access of local distributed sources and loads and the safe and high-quality power supply of the local area, and at the same time, each module is independently set and has independent functions, and each module has a clear The functions and interfaces are defined, which is convenient for upgrading, maintenance and troubleshooting, and has strong scalability, which is convenient for flexible combination and expansion according to needs in the later stage. The present invention adopts an input unit, a central processing unit, an output unit, a communication unit and a human-computer interaction unit. The equipment can provide flexible access to the source network and the load storage through multiple ports, and can reduce the three-phase imbalance rate to below 1%, the total harmonic distortion rate to below 1%, the voltage and power factor qualification rate to more than 99%, the single-phase distributed photovoltaic carrying capacity and the electric vehicle AC charging pile access capacity to increase by 200%, and the comprehensive line loss to reduce by 10%. In general, the present invention has the advantages of high safety and reliability, high efficiency, high flexibility and high economy. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the composition structure of the present invention. DETAILED DESCRIPTION

[0014] The technical solution of the present invention is further specifically described below through embodiments and in conjunction with the accompanying drawings.

[0015] like Figure 1As shown, the present invention provides a low-voltage multi-port single-phase power supply device, which is mainly composed of an input unit, a central processing unit, an output unit, a communication unit and a human-computer interaction unit. The input unit receives power, and the output unit distributes power. The central processing unit contains a central processing unit (CPU / DSP), a memory and a three-phase unbalance control module, a harmonic control module, a voltage fluctuation and flicker suppression module, a voltage reactive power control module and a source-grid-load-storage coordination optimization module and other control logic modules. Each module works under the unified coordination of the central processing unit, which can effectively solve various problems in the low-voltage distribution network, such as low voltage qualification rate, large line loss, serious three-phase imbalance, limited distributed power supply carrying capacity and load access capacity, etc., to achieve optimized control and stable power supply of the low-voltage distribution network, and realize flexible access of local distributed sources and loads and safe and high-quality power supply in local areas.

[0016] The input unit includes multiple independently controlled input terminals that are adapted to different types of power access settings. The power types include the upper power grid, local distributed power sources and local energy storage systems. Distributed power sources include photovoltaic power generation and wind power.

[0017] Specifically, in order to ensure safe access and stable operation of the power supply, the input end of the superior power grid is installed with circuit breakers, fuses, lightning arresters and power quality monitoring modules to receive the three-phase power supply from the superior power grid; the input end of the local distributed power supply and the local energy storage system is installed with circuit breakers, fuses, lightning arresters, power quality monitoring modules and AC-DC conversion devices to receive the three-phase power supply from the local distributed power supply and the local energy storage system after conversion by the AC-DC conversion device; the power quality monitoring module is used to monitor the voltage, current and frequency parameters of the input power supply in real time to provide data support for subsequent control.

[0018] The central processing unit includes a central processing unit, a memory and multiple control logic modules. The central processing unit is the core processing unit of the device and is responsible for executing various control algorithms and data processing tasks. The memory is used to store the program code, data and parameters of the device. The control logic modules include a three-phase unbalanced control module, a harmonic control module, a voltage fluctuation and flicker suppression module, a voltage reactive power control module and a source-grid-load-storage coordination optimization module.

[0019] Specifically, the three-phase unbalanced control module includes an intelligent switching switch or a dynamic reactive power compensation device, an intelligent algorithm, and current sensors installed on each phase. The central processing unit monitors the three-phase current size and phase difference collected by the current sensor in real time through the intelligent algorithm, and uses the intelligent switching switch or the dynamic reactive power compensation device to automatically adjust the load distribution to ensure that the imbalance of the three-phase current is within the allowable range.

[0020] Specifically, the harmonic control module adopts a harmonic filter, which is installed at key nodes to monitor the harmonic level in real time and dynamically adjust the filter parameters as needed to absorb or eliminate harmonics. The harmonic filter includes an active filter and / or a passive filter. The key nodes are each input port, each load port, the common connection point on the load side, and the energy storage module.

[0021] Harmonic filters include active filters and passive filters. Active filters can monitor the harmonic currents in the power grid in real time and generate opposite currents to offset them. Passive filters filter harmonics of specific frequencies through a combination of components such as inductors and capacitors.

[0022] Specifically, the voltage fluctuation and flicker suppression module adopts a dynamic voltage regulator or a static synchronous compensator, sets a reasonable response time and voltage range, monitors in real time and quickly compensates for voltage fluctuations and flickers; the dynamic voltage regulator can detect voltage fluctuations within milliseconds and maintain voltage stability at the load end by injecting compensation voltage; the static synchronous compensator can achieve stable control of voltage by quickly adjusting reactive power.

[0023] Specifically, the voltage reactive power control module adopts a static reactive power generator or a static reactive power compensator and an intelligent controller to monitor load changes and grid demand in real time, and automatically adjust reactive power output to keep the power factor within a reasonable range; the static reactive power compensator, such as a capacitor bank, a reactor, etc., can compensate for the reactive power of the grid; the intelligent controller can automatically adjust the switching of the reactive power compensation device according to the operating status of the grid to achieve optimal control of voltage and reactive power.

[0024] Specifically, the source-grid-load-storage coordination optimization module adopts an integrated energy management system, which is used to achieve coordinated and optimized operation among the upper-level power grid, local distributed power sources, local energy storage systems and loads through output forecasting of distributed power sources, load demand forecasting and charging and discharging control of energy storage equipment.

[0025] The output unit includes multiple single-phase output terminals that are independently controlled and adapted to different loads. Different loads refer to those with different voltage and current level requirements, such as lighting, air conditioning, etc., and / or different types of output ports, such as sockets, terminal blocks, etc., but all output ports must comply with relevant safety standards and specifications, such as IEC, UL, etc.

[0026] Specifically, in order to ensure the safe output and stable operation of the power supply, each single-phase output terminal is installed with various protection devices such as overload protection, short circuit protection, grounding protection and overheating protection.

[0027] The communication unit is one or more of Ethernet, RS-485, CAN, and wireless communication technologies, which are used to realize the remote monitoring and operation functions of the equipment.

[0028] The human-computer interaction unit includes a display screen and operation buttons. The display screen is used to display the operating status and parameters of the equipment, and the operation buttons are used for manual operation settings.

[0029] In specific implementation, the total capacity of the equipment shall not be less than 25kVA to meet the application requirements of different scales.

[0030] During operation, the superior power grid, local distributed power sources and local energy storage systems are connected to the equipment through the input unit, and various loads are connected to the equipment through the output unit. The equipment works stably under the unified coordination of the central processing unit to provide safe and high-quality power supply for low-voltage users. During operation, the staff can view the equipment and perform basic operations through the display screen and operation buttons. During operation, the communication unit provides a data transmission channel for various sensors and the central processing unit. At the same time, the equipment can also be connected to the superior monitoring system or smart grid platform through the communication unit to realize data sharing and remote control. During operation, the three-phase unbalanced control module, harmonic control module, voltage fluctuation and flicker suppression module, voltage reactive power control module and source-grid-load-storage coordinated optimization module operate separately to monitor the equipment operating parameters in real time and ensure the stability of power input and output.

[0031] In summary, the new low-voltage single-phase multi-port power supply equipment provided by the present invention can realize flexible control of three-phase imbalance, with better control performance and control effect, and can reduce the three-phase imbalance rate to below 1%. At the same time, it has the functions of harmonic control, voltage reactive power control, source-grid-load-storage coordinated optimization, etc., and can reduce the total harmonic distortion rate to below 1%. The voltage and power factor qualification rate reaches more than 99%, and the single-phase distributed photovoltaic carrying capacity and electric vehicle AC charging pile access capacity are increased by 200%, and the comprehensive line loss is reduced by 10%. It can solve the problems of low-voltage three-phase imbalance, voltage fluctuation and flicker, harmonics, voltage over-limit, etc. on-site, improve the power supply quality and reliability in rural areas, and provide more stable power supply for residents in rural areas, thereby improving the quality of life.

[0032] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that the specific implementation modes of the present invention can still be modified or replaced by equivalents, and any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A low-voltage multi-port single-phase power supply device, characterized in that: It includes an input unit, a central processing unit, an output unit, a communication unit and a human-computer interaction unit; The input unit includes a plurality of input terminals which are independently controlled and respectively adapted to different types of electric energy access settings, the electric energy types include the upper power grid, the local distributed power source and the local energy storage system, and the distributed power source includes photovoltaic power generation and wind power; The central processing unit includes a central processing unit, a memory and a plurality of control logic modules. The central processing unit is the core processing unit of the device and is responsible for executing various control algorithms and data processing tasks. The memory is used to store the program code, data and parameters of the device. The control logic module includes a three-phase unbalanced control module, a harmonic control module, a voltage fluctuation and flicker suppression module, a voltage reactive power control module and a source-grid-load-storage coordination optimization module. The output unit includes a plurality of single-phase output terminals that are independently controlled and adapted to different loads. Different loads refer to loads with different voltage and current level requirements and / or different types of output ports, but all output ports shall comply with relevant safety standards and specifications; The communication unit is one or more of Ethernet, RS-485, CAN, and wireless communication technologies, and is used to realize the remote monitoring and operation functions of the equipment; The human-machine interaction unit includes a display screen and operation buttons, the display screen is used to display the operating status and parameters of the device, and the operation buttons are used for manual operation settings; The superior power grid, local distributed power sources and local energy storage systems are connected to the equipment through input units, and various loads are connected to the equipment through output units. The equipment works stably under the unified coordination of the central processing unit to provide safe and high-quality power supply for low-voltage users.

2. The low-voltage multi-port single-phase power supply device according to claim 1, characterized in that: The input end of the upper power grid is equipped with a circuit breaker, a fuse, a lightning arrester and a power quality monitoring module. The input end of the local distributed power supply and the local energy storage system is equipped with a circuit breaker, a fuse, a lightning arrester, a power quality monitoring module and an AC-DC conversion device. The power quality monitoring module is used to monitor the voltage, current and frequency parameters of the input power supply in real time to provide data support for subsequent control.

3. The low-voltage multi-port single-phase power supply device according to claim 1, characterized in that: The single-phase output end is equipped with an overload protection device, a short circuit protection device and an overheat protection device.

4. The low-voltage multi-port single-phase power supply device according to claim 1, characterized in that: The three-phase imbalance control module includes an intelligent switching switch or a dynamic reactive power compensation device, an intelligent algorithm, and a current sensor installed on each phase. The central processing unit monitors the three-phase current size and phase difference collected by the current sensor in real time through the intelligent algorithm, and uses the intelligent switching switch or the dynamic reactive power compensation device to automatically adjust the load distribution to ensure that the imbalance of the three-phase current is within the allowable range.

5. The low-voltage multi-port single-phase power supply device according to claim 1, characterized in that: The harmonic control module adopts a harmonic filter, which is installed at key nodes to monitor the harmonic level in real time and dynamically adjust the filter parameters as needed to absorb or eliminate harmonics. The harmonic filter includes an active filter and / or a passive filter. The key nodes are each input port, each load port, the common connection point on the load side, and the energy storage module.

6. The low-voltage multi-port single-phase power supply device according to claim 1, characterized in that: The voltage fluctuation and flicker suppression module adopts a dynamic voltage regulator or a static synchronous compensator, sets a reasonable response time and voltage range, monitors in real time, and quickly compensates for voltage fluctuations and flickers.

7. The low-voltage multi-port single-phase power supply device according to claim 1, characterized in that: The voltage reactive power control module adopts a static reactive power generator or a static reactive power compensator and an intelligent controller to monitor load changes and grid demand in real time, and automatically adjust reactive power output to keep the power factor within a reasonable range.

8. The low-voltage multi-port single-phase power supply device according to claim 1, characterized in that: The source-grid-load-storage coordination optimization module adopts an integrated energy management system, which is used to achieve coordinated and optimized operation between the upper power grid, local distributed power sources, local energy storage systems and loads through output prediction of distributed power sources, load demand prediction and charging and discharging control of energy storage equipment.

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