WO2023066317A1 - 一种关断器、关断器的通信方法及快速关断光伏系统 - Google Patents

一种关断器、关断器的通信方法及快速关断光伏系统 Download PDF

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Publication number
WO2023066317A1
WO2023066317A1 PCT/CN2022/126260 CN2022126260W WO2023066317A1 WO 2023066317 A1 WO2023066317 A1 WO 2023066317A1 CN 2022126260 W CN2022126260 W CN 2022126260W WO 2023066317 A1 WO2023066317 A1 WO 2023066317A1
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Prior art keywords
switch
control signal
power
signal
input
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PCT/CN2022/126260
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English (en)
French (fr)
Inventor
禹红斌
周世高
吴彦伟
赵一
杨波
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杭州禾迈电力电子股份有限公司
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Priority to CN202280006867.0A priority Critical patent/CN116406489A/zh
Publication of WO2023066317A1 publication Critical patent/WO2023066317A1/zh

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    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02JCIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00Circuit arrangements for ac mains or ac distribution networks
    • H02J3/38Arrangements for parallely feeding a single network by two or more generators, converters or transformers

Definitions

  • the invention relates to the technical field of distributed photovoltaic power generation, and in particular to a switch, a communication method for the switch, and a fast shutdown photovoltaic system.
  • the string photovoltaic system Due to the advantages of mature technology, high conversion efficiency, high integration, and low price, the string photovoltaic system has been widely used in distributed photovoltaic systems such as household and industrial and commercial roofs, as well as ground power stations.
  • the photovoltaic system catches fire
  • the DC high voltage of the string photovoltaic system brings a serious risk of electric shock to the fire on the roof. It is extremely difficult to fire and extinguish the fire. In most cases, the fire can only be allowed to spread.
  • NEC National Electrical Code
  • the 2017 version of the National Electrical Code (NEC) introduced the component-level rapid shutdown function, requiring the voltage on any conductor inside the photovoltaic array to drop below 80V within 30s after triggering the rapid shutdown function. The voltage on the outer conductor of the array drops below 30V within 30s, and then the UL1741 standard also added the evaluation method of the quick shutdown device and the quick shutdown system.
  • the solution for the string photovoltaic system to meet the fast shutdown requirements of NEC 2017 is to add component-level fast shutdown devices, including shutdown devices and optimizers. Due to the low cost of shutdown devices, most shutdown devices are compatible with Sunspec fast shutdown devices. Shutdown protocols can be used interchangeably, so they are widely used in string photovoltaic systems.
  • the Sunspec fast shutdown protocol is a simple and reliable one-way power line carrier communication protocol.
  • the traditional disconnector using this protocol is simple, reliable and low in cost, but it only has a receiving function and cannot send information, and cannot realize component-level monitoring. When the switch, components, etc. are abnormal, troubleshooting is time-consuming and laborious.
  • Sunspec fast shutdown protocol receiver in the switch with a power line carrier transceiver module, which realizes the two-way communication function of the switch, and then provides component-level monitoring, but it increases a lot of costs, and other manufacturers will
  • the Sunspec fast shutdown protocol receiver was replaced with a wireless communication transceiver to realize two-way communication function, but the wireless communication is not very stable in the field, and a relay is needed to improve the stability of the field communication, which increases the communication complexity and cost of the system.
  • the object of the present invention is to provide a disconnector, a communication method for the disconnector and a fast shutdown photovoltaic system, which can improve the integration and power density of the disconnector, and greatly reduce the production cost of the product.
  • the present invention provides a switch, which includes:
  • the first input terminal is used for coupling the first DC power supply
  • At least one second input terminal used for coupling a second DC power supply
  • the first shutdown module is connected to the first input terminal, the first shutdown module includes a first switch tube, and the first switch tube is used to control the output power of the first DC power supply coupled to the first input terminal;
  • At least one second shutdown module connected to the second input terminal includes a second switch tube, the second switch tube is used to control the output power of the second DC power supply coupled to the second input terminal;
  • the outputs of the first shutdown module and at least one second shutdown module are connected in series and connected to the output terminal;
  • a control module configured to modulate a power control signal and the first communication signal to generate a first composite control signal, wherein the power control signal adjusts the output power of the first DC power source coupled to the first input terminal, so The first composite control signal controls the first switching tube to work in a high-frequency switching state, so as to superimpose a current ripple signal including the first communication signal on the power bus;
  • the control module is also used to generate a switch control signal to control the working state of the second switch tube.
  • control module adjusts the magnitude of the power control signal according to the power bus current, and then controls the duty cycle of the first composite control signal, so that the ripple peak value of the input voltage at the input end of the switch is within a predetermined range. within the set ripple threshold.
  • the duty ratio of the first composite control signal is positively correlated with the power bus current, the larger the power bus current is, the larger the duty ratio is, otherwise the smaller the duty ratio is.
  • control module includes:
  • a power control unit configured to generate a power control signal according to the power bus current
  • a modulation unit configured to receive the first communication signal and the power control signal, and modulate the first communication signal and the power control signal to generate the first composite control signal
  • a switch control unit configured to generate a switch control signal for controlling the working state of the second switch tube.
  • control module also includes:
  • the monitoring unit is used to collect and obtain the operating data of the circuit breaker
  • An integrated control unit configured to pack the operating data of the circuit breaker into a first data packet
  • a protocol processing unit configured to encapsulate the first data packet into the first communication signal according to a predetermined communication protocol, and send it to the modulation unit.
  • the integrated control unit packs the operating data of the switch into a first data packet and sends it to the protocol processing unit, and the first composite control signal controls the first switching tube to work at In a high-frequency switching state, the switch control signal controls the second switching tube to be in a normally-on state;
  • the first composite control signal controls the first switch tube to work in a normally-on state
  • the switch control signal controls the second switch tube to maintain a normally-on state
  • the switch also includes a signal decoupling module, which separates the power line carrier signal from the power bus from the power bus current, and extracts the power line carrier signal;
  • the control module further includes a demodulation unit, configured to demodulate the extracted power line carrier signal to obtain a second communication signal;
  • the protocol processing unit is further configured to analyze the second communication signal according to the protocol format to obtain a second data packet, and transmit the second data packet to the integrated control unit, and the integrated control unit analyzes the second data packet to obtain the second data packet.
  • the control instruction in the second data packet is used to control the working state of the switch.
  • control module controls the duty ratio of the first composite control signal according to the input voltage of the first shut-off module during data transmission.
  • the duty cycle of the first composite control signal is increased, and when the peak value of the first shut-off module When the peak value of the input voltage is smaller than the first reference voltage, the duty cycle of the first composite control signal is reduced.
  • the average value of the input voltage of the first shutdown module is greater than or equal to the preset second reference voltage, increase the duty cycle of the first composite control signal, and when the first shutdown module When the average value of the input voltage is smaller than the second reference voltage, the duty cycle of the first composite control signal is reduced.
  • the monitoring unit detects that the input voltage of the first shutdown module of the switch is lower than the preset voltage threshold, it determines that the input state of the first input terminal is abnormal, otherwise it is normal, and outputs An input state detection signal used to represent the input state of the first input terminal.
  • control module also includes:
  • a voltage control unit configured to generate a voltage control signal according to the input voltage of the first shutdown module
  • a selection unit connected to the power control unit and the voltage control unit, is used to select and output the power control signal or the voltage control signal according to the input state detection signal, so as to control the first composite control signal duty cycle.
  • the selection unit selects to output the power control signal, and the modulation unit modulates the first communication signal and the power control signal to generate the first Composite control signal;
  • the selection unit selects to output the voltage control signal during data transmission, and the modulation unit modulates the first communication signal and the voltage control signal to generate the second communication signal.
  • a composite control signal when the data transmission is completed, the selection unit selects and outputs the power control signal.
  • the voltage control unit includes:
  • an error amplifier configured to obtain an error amplification value between the input voltage of the first shutdown module and a reference voltage
  • a controller configured to generate the voltage control signal according to the error amplification value.
  • the second DC power supply connected to the second shutdown module adjacent to the first shutdown module is used to provide power to the control module.
  • the shut-off device further includes sampling resistors, the sampling resistors are respectively connected to the first shut-off module and the second shut-off module adjacent to the first shut-off module, and the sampling resistors use For obtaining the power bus current, the connection point between the sampling resistor and the first shutdown module is used as a common ground.
  • the present invention provides a communication method of a circuit breaker, the method comprising:
  • the first composite control signal controls the first switching tube at the first input end of the switch to work in a high-frequency switching state, so as to superimpose a current ripple signal including the first communication signal on the power bus;
  • a switch control signal is provided, and the switch control signal is used to control the working state of the second switch tube at the second input end of the switch.
  • the method also includes:
  • the method also includes:
  • the first switching tube of the switch works in a high-frequency switching state, and the switch control signal controls the second switching tube of the switching device to be in a normally-on state;
  • the first composite control signal controls the first switch tube to work in a normally-on state
  • the switch control signal controls the second switch tube to keep in a normally-on state
  • the method also includes:
  • the duty ratio of the first composite control signal is controlled according to the input voltage of the first shut-off module of the shut-off device during data transmission.
  • the method also includes:
  • the method also includes:
  • the method also includes:
  • a voltage control signal is generated according to the input voltage of the first shutdown module, and the first communication signal and the voltage control signal are modulated.
  • the first composite control signal is generated, and when the data transmission is completed, the first communication signal and the power control signal are modulated to generate the first composite control signal.
  • the present invention provides a fast shutdown photovoltaic system
  • the system includes a plurality of disconnectors, a plurality of photovoltaic modules, a main controller and a photovoltaic inverter, and each disconnector is connected to the first photovoltaic component and the second photovoltaic component, a plurality of disconnectors are connected in series on a power bus, and the power bus is connected to the DC input port of the photovoltaic inverter, and the disconnector includes a first input terminal, at least one second The input end, the first shut-off module connected to the first input end, the second shut-off module connected to the first input end, the output end and the control module, the first shut-off module includes a first switch tube, the first shut-off module The second shutdown module includes a second switch tube, wherein,
  • the switch is configured to modulate the power control signal and the first communication signal, and modulate to generate a first composite control signal, the power control signal adjusts the output power of the first DC power supply coupled to the first input terminal , the first composite control signal controls the first switching tube to work in a high-frequency switching state, so as to superimpose the current ripple signal including the first communication signal on the power bus, and the switch is also used for generating a switch control signal to control the working state of the second switch tube;
  • the main controller is used to extract the current ripple signal in the power bus, perform demodulation and analysis processing, and obtain the first communication signal sent by the switch.
  • the switch in the present invention includes a plurality of input terminals, which is a multi-input topology structure, and the switching tube of the switch-off module corresponding to any input terminal can be selected to work in a high-frequency switching state, so as to realize the coupling of the operating data of the switch
  • multiple shutdown modules share one control module, which can improve the integration and power density of the disconnector, and greatly reduce the production cost of the product; in the multi-input disconnector, when used
  • the duty cycle of the composite control signal is adjusted according to the input voltage of the shutdown module, and the strength of the power line carrier signal is increased, so that the communication data can be realized when the photovoltaic module is abnormal. Send it normally.
  • FIG. 1 is a system block diagram of a switch according to a first embodiment of the present invention
  • FIG. 2 is a waveform diagram of input and output voltages when the circuit breaker performs data transmission according to an embodiment of the present invention
  • Fig. 3 is a schematic block diagram of a modulation unit of a switch according to a first embodiment of the present invention
  • FIG. 4 is a system block diagram of a switch according to a second embodiment of the present invention.
  • FIG. 5 is a schematic block diagram of a modulation unit of a switch according to a second embodiment of the present invention.
  • FIG. 6 is a system block diagram of a switch according to a third embodiment of the present invention.
  • Fig. 7 is a waveform diagram of input and output voltages when the circuit breaker performs data transmission according to the third embodiment of the present invention.
  • FIG. 8 is a system block diagram of a switch according to a fourth embodiment of the present invention.
  • FIG. 9 is a waveform diagram of input and output voltages when the circuit breaker performs data transmission according to the fourth embodiment of the present invention.
  • FIG. 10 is a system block diagram of a switch according to a fifth embodiment of the present invention.
  • FIG. 11 is a system schematic diagram of a rapid shutdown photovoltaic system according to an embodiment of the present invention.
  • the present invention provides a switch, which includes:
  • the output terminal 11 is used for coupling the power bus
  • At least one shutdown module 12 corresponds to an input terminal 10, and includes at least one switch tube 1221, and the switch tube 1221 is used to control the output power of the DC power supply coupled to the input terminal 10:
  • the control module 13 is configured to modulate a power control signal and the first communication signal to generate a first composite control signal, wherein,
  • a power control signal used to adjust the output power of the DC power supply coupled to the input terminal 10;
  • the first composite control signal is used to control the switching tube 1221 to work in a high-frequency switching state, so as to superimpose the current ripple signal including the first communication signal on the power bus.
  • the DC power supply contains at least one cell, generally a photovoltaic module or two photovoltaic modules connected in series.
  • the present invention is illustrated by taking the DC power supply as a photovoltaic module as an example, and one input terminal 10 corresponds to one photovoltaic module.
  • the shutdown module 12 includes, for example, a plurality of switch tubes connected in series and/or in parallel, and the data transmission function is realized by controlling any switch tube to work in a high-frequency switching state.
  • the switch includes an input terminal 10 , an output terminal 11 , a shutdown module 12 , a control module 13 and the shutdown module 12 includes a switch tube 1221 , but not limited thereto.
  • the switch tube 1221 is connected between the input terminal 10 and the output terminal 11 to control the output power of the photovoltaic module coupled to the input terminal 10 .
  • the switch tube 1221 can be located between the high potential end of the input end 10 and the high potential end of the output end 11, or between the low potential end of the input end 10 and the low potential end of the output end 11.
  • the control module 13 is coupled to the shut-off module 12, generates a first composite control signal for controlling the switching tube 1221 according to the first communication signal and the power bus current, and the first composite control signal adjusts the power of the shut-off device.
  • the output power of the photovoltaic module coupled to the input terminal 10 and the control switching tube 1221 to work in a high-frequency switching state are used to couple the first communication signal to the power bus for transmission.
  • the power bus connects the output ends of multiple disconnectors in series to connect to the photovoltaic inverter.
  • the length of the line is tens of meters to hundreds of meters, and the parasitic inductance of the loop is generally between 7.8uH and 269uH.
  • the power bus current is controlled by the photovoltaic inverter, and the photovoltaic inverter realizes the maximum power output of each photovoltaic module in the photovoltaic system by regulating the power bus current.
  • the first communication signal includes the communication data of the circuit breaker, and the communication data includes the operation data of the circuit breaker, etc., but is not limited thereto. In other embodiments, the first communication signal may also contain other Any data that needs to be sent.
  • the control module 13 adjusts the size of the power control signal according to the power bus current, and then controls the duty ratio of the first composite control signal, so that the peak value of the ripple of the input voltage at the input terminal of the switch is within a range of Within the preset ripple threshold, the steady-state operating point of the photovoltaic module fluctuates greatly, resulting in the problem that the output power of the photovoltaic module is reduced when the switching tube 1221 performs high-frequency switching operations.
  • the duty cycle of the first composite control signal is positively correlated with the power bus current, the larger the power bus current is, the larger the duty cycle is, otherwise the smaller the duty cycle is.
  • the shutdown module 12 further includes an input unit 121 coupled to the input terminal 10 and an output unit 123 coupled to the output terminal 11.
  • the input unit 121 includes an input capacitor Cin for stabilizing The input voltage Vin of the switch.
  • the output unit 123 includes an output capacitor Co for stabilizing the output voltage Vo of the switch.
  • I is the power bus current
  • T is the period of the first composite control signal
  • D is the duty ratio of the first composite control signal
  • C o is the capacitance of the output capacitor Co.
  • the output current of the photovoltaic module charges the input capacitor Cin, and the input voltage Vin at both ends of the input capacitor Cin is raised.
  • the input voltage Vin of the switch fluctuates slightly, and the fluctuation value is less than 10% of the output voltage of the photovoltaic module, which has little effect on the output current of the photovoltaic module.
  • the output current of the component can be considered basically unchanged, which is approximately equal to the power bus current.
  • the input voltage Vin of the switch rises linearly during this period, and its overcharge voltage ⁇ Vin is shown in formula (2):
  • C in is the capacitance value of the input capacitor Cin.
  • the energy stored in the input capacitor Cin is quickly transferred to the output capacitor Co through the switch tube 1221 when the switch tube 1221 is turned off, compensating the energy released by the output capacitor Co during the switch off period of the switch tube 1221.
  • the input voltage Vin and output voltage Vo of the breaker return to the steady-state voltage, and the output voltage of the photovoltaic module also returns to the steady-state voltage.
  • the photovoltaic inverter still controls the output voltage of the photovoltaic module by adjusting the power bus current to make it work at maximum power point.
  • the switch needs to adjust the duty cycle D according to the power bus current, for example, according to the proportional relationship in formula (1) or formula (2), so that when the switch tube 1221 is turned off, the input voltage Vin of the switch is
  • the overcharge voltage ⁇ Vin is less than 10% of the output voltage of the photovoltaic module, so as to prevent the operating point of the photovoltaic module from deviating from the maximum power point and reduce the output power of the photovoltaic module.
  • the output voltage Vo of the shut-off device contains abundant high-frequency switching tube harmonics, and the Fourier decomposition of the output voltage Vo can obtain the DC component and the fundamental wave of the output voltage Vo component and each harmonic component, wherein the frequency of the fundamental component is the switching frequency of the switching tube 1221 .
  • the power bus Under the excitation of the fundamental wave component of the output voltage Vo, the power bus generates a corresponding fundamental wave current ripple.
  • the fundamental wave component contained in the output voltage of the circuit breaker is modulated according to the first communication signal containing the operation data of the circuit breaker, and the power line carrier signal carrying the first communication signal can be injected into the power bus, which can Realize the data transmission function of the switch.
  • the power line carrier signal is the fundamental wave component of the current ripple signal, that is, the fundamental current ripple.
  • the typical value of the input capacitor Cin of the switch is 1uF
  • the typical value of the output capacitor Co is 1uF
  • the switching frequency is 100kHz
  • the impedance of the power bus at this switching frequency is 100 ohms.
  • the input voltage Vin of the switch is 40V
  • the power bus current is 2A
  • the overcharge voltage ⁇ Vin is controlled to 2V, according to the formulas (1) and (2)
  • the duty cycle D 0.9
  • the drop voltage ⁇ Vo is 2V
  • the input The waveforms of the voltage Vin and the output voltage Vo are shown in Fig. 2 .
  • Fourier decomposition is performed on the waveform of the output voltage Vo, and the DC component, fundamental component and harmonic components of the output voltage Vo can be obtained.
  • the control module 13 includes a power control unit 131 and a modulation unit 132 .
  • the power control unit 131 generates a power control signal according to the power bus current, and outputs it to the modulation unit 132 .
  • the modulation unit 132 receives the first communication signal and the power control signal, modulates the first communication signal and the power control signal, and generates a first composite control signal.
  • the first composite control signal controls the switching tube 1221 to perform high-frequency switching operations.
  • the switching tube 1221 performs high-frequency switching action under the control of the first composite control signal, so that a corresponding fundamental voltage ripple is generated on the output terminal of the switch.
  • the power bus Under the excitation of the fundamental voltage ripple, the power bus The corresponding fundamental current ripple is generated to couple the first communication signal containing the operating data to the power bus, and the current ripple signal carrying the operating data is generated on the power bus to realize the function of sending data of the switch, which does not require traditional
  • the power line carrier transceiver module or wireless communication module in the disconnector can realize the data transmission function of the disconnector.
  • the modulation unit 132 modulates the received power control signal and the first communication signal to generate a first composite control signal.
  • the power control signal and the first communication signal are modulated based on a variety of mature modulation techniques, that is, the fundamental component of the output voltage of the switch is modulated, so that the fundamental current ripple in the power bus carries the The first communication signal of the operating data of the device.
  • the mature modulation techniques that can be used include FSK (Frequency shift keying frequency shift keying), PSK (Phase shift keying phase shift keying) and so on.
  • FSK modulation technology is simple to implement, and has better anti-noise and anti-attenuation performance. It has been widely used in low-to-medium rate digital communications.
  • FSK modulation technology has two symbols, the mark frequency Fm (mark frequency) and the space frequency Fs (space frequency).
  • the mark frequency Fm is used to represent the number "1"
  • the space frequency Fs is used to represent the number "0”.
  • Fig. 3 shows a schematic block diagram of the modulation unit 132, and the modulation unit 132 includes a selection switch S and a first comparator U1.
  • the first input terminal of the first comparator U1 receives the power control signal, the second input terminal is connected to the first terminal of the selection switch S, and the output terminal outputs the first composite control signal.
  • the second end of the selection switch S receives the carrier signal of the mark frequency Fm, and the third end receives the carrier signal of the space frequency Fs.
  • the first communication signal controls the selection switch S to select carrier signals of different frequencies. When the first communication signal bit is "1", the carrier signal of the mark frequency Fm is selected.
  • the spatial frequency is selected.
  • the power control signal is compared with the carrier signal to obtain a first composite control signal.
  • the first composite control signal controls the switching tube 1221 to work in a high-frequency switching state, and its frequency determines the frequency of the fundamental component of the output voltage Vo, and accordingly, also determines the frequency of the fundamental component of the current ripple signal.
  • the first composite control The duty cycle of the signal determines the voltage ripple of the input/output voltage of the switch, thus indirectly controlling the output power of the photovoltaic module.
  • the control module 13 further includes a monitoring unit 133 , an integrated control unit 134 and a protocol processing unit 135 .
  • the monitoring unit 133 collects and obtains the operating data of the circuit breaker, and sends it to the integrated control unit 134 .
  • the operating data of the breaker includes the input and output electrical parameters and internal operating data of the breaker, wherein the input and output electrical parameters include the output voltage, output current, Power generation, output voltage and power bus current of the circuit breaker, the internal operating data includes temperature, operation status and alarm information of the circuit breaker.
  • the integrated control unit 134 packs the operating data of the switch into a first data packet, and sends it to the protocol processing unit 135 .
  • the protocol processing unit 135 encapsulates the first data packet according to a predetermined communication protocol into a first communication signal, and sends the first communication signal to the modulation unit 132 .
  • control module 13 further includes a drive unit 136, which is connected to the modulation unit 132, and generates a first drive signal according to the received first composite control signal, and the first drive signal controls the conduction of the switching tube 1221. on and off.
  • the switch further includes a signal decoupling module 14, which separates the power line carrier signal from the power bus from the power bus current, and extracts the power line carrier signal.
  • the signal decoupling module 14 is composed of an RLC parallel resonant circuit, the RLC parallel resonant circuit is a bandpass filter, the frequency of the power line carrier signal is within the passband of the bandpass filter, and the RLC parallel resonant circuit provides a stable impedance for the power line carrier signal , so that the power line carrier signal is extracted from the power line.
  • the control module 13 also includes a demodulation unit 137, which receives the power line carrier signal extracted by the signal decoupling module 14, performs filtering and amplification processing on the power line carrier signal, obtains a power line carrier signal with a better signal-to-noise ratio, and performs demodulation processing , to obtain a second communication signal, and send the second communication signal to the protocol processing unit 135 .
  • the protocol processing unit 135 parses the received second communication signal into a second data packet according to the protocol format, and delivers the second data packet to the integrated control unit 134 .
  • the integrated control unit 134 analyzes the second data packet, obtains the control instruction in the second data packet, and adjusts the operating mode of the shutter according to the control instruction of the shutter. instructions and data acquisition instructions.
  • the mode of operation of the disconnector includes a safe disconnection mode and a normal operation mode.
  • the protocol processing unit 135 also generates a data transmission status signal to the power control unit 131.
  • the data transmission status signal represents the status of the switch sending data, including two states of idle and busy.
  • the power control unit 131 sends the status signal to the switch according to the data.
  • the operating mode adjusts the working state of the switching tube 1221.
  • the initial mode of the switch after power-on is the safe disconnection mode
  • the integrated control unit 134 when the integrated control unit 134 receives the instruction to allow the operation, it switches the operation mode of the switch to the normal operation mode.
  • the comprehensive control unit 134 does not receive the operation permission instruction or receives the fast shutdown instruction after the first preset time, the operation mode of the switch is switched to the safe disconnection mode.
  • the switch when the switch is in the normal operation mode, if the integrated control unit 134 receives a data collection instruction, it will pack the operating data of the switch into a first data packet, and the protocol processing unit 135 will The first data packet is encapsulated into a first communication signal, sent to the modulation unit 132, and the data sending status signal is set to a busy state.
  • the power control unit 131 adjusts the magnitude of the power control signal according to the power bus current, and then adjusts the duty cycle of the first composite control signal.
  • the modulation unit 132 modulates the first communication signal and the power control signal to generate a first composite control signal.
  • the first composite control signal controls the switching tube 1221 to work in a high-frequency switching state to generate a portable switch on the power bus.
  • the current ripple signal of the operating data After the first data packet transmission is completed, the protocol processing unit 135 sets the data transmission state signal to an idle state, and the power control unit 131 adjusts the power control signal to a first preset value.
  • the first composite control signal The control switch tube 1221 works in a normally-on state.
  • the power control unit 131 adjusts the power control signal to a second preset value, and at this time, the first composite control signal controls the switching tube 1221 to work in the disconnected state.
  • the modulation unit 132 when the switch is in the safe disconnection mode, the modulation unit 132 outputs a low-level first composite control signal to control the switching tube 1221 to be in the off state, and the output voltage of the switch and The power is in a controlled and safe state.
  • the modulation unit 132 When the switch is in the normal operation mode and the data transmission state signal is in the idle state, the modulation unit 132 outputs a high-level first composite control signal to control the switch tube 1221 to be in the normally-on state.
  • the modulation unit 132 When the switch is in the normal operation mode and the data transmission status signal is busy, the modulation unit 132 outputs a modulated first composite control signal, and the first composite control signal controls the switching tube 1221 to be in a high-frequency switching state.
  • the power control signal adjusts the duty cycle of the first composite control signal according to the power bus current, controls the fluctuation range of the operating point of the photovoltaic module, and makes the ripple peak value of the input voltage at the input end of the switcher be within the preset ripple threshold, The drop range of the output power of the photovoltaic module caused by the input voltage ripple of the switch in the high-frequency switching state of the switching tube 1221 is reduced.
  • the switch tube 1221 When the switch is in the safe disconnection mode, like a traditional switch, the switch tube 1221 is in the off state, the photovoltaic module connected to the input terminal 10 is disconnected from the power bus, the output of the photovoltaic module is in an open state, and the output The power is close to zero, and the output voltage and power of the circuit breaker are limited.
  • the switch When the switch is in normal operation mode and the switch tube 1221 is in the normally-on state, the output voltage of the switch is equal to the input voltage, the output power of the switch is equal to the output power of the photovoltaic module, and the output power of the photovoltaic module is determined by the power The bus current is regulated, and the power bus current is controlled by the photovoltaic inverter connected to the power bus.
  • the operating data of the switch is coupled to the power bus, and the output power of the photovoltaic module is determined by the power bus current and the first composite control signal. Air ratio control.
  • the switch also includes a relief module 15.
  • the integrated control unit 134 controls to open the discharge module 15 to provide a relief module.
  • the discharge channel quickly discharges the power bus voltage below the safe voltage within the specified time, that is, discharges the output voltage of the power bus below 30V within 30s to meet the requirements of the North American Electrical Code NEC2017.
  • the discharge current is generally 5-10mA.
  • the power bus current may be extremely low, such as less than 1mA.
  • the formula (2) and the parameters of a specific embodiment of the present invention when the input voltage Vin of the switch is 40V , when the power bus current is 1mA, when the duty cycle D is 0.5, the drop voltage ⁇ Vo of the output voltage Vo is 5mV, and the Fourier analysis is performed on the waveform of the output voltage Vo, and the amplitude of its fundamental component can be obtained as 1.9mV , the amplitude of the fundamental current ripple in the power bus is 19uA, and the strength of the generated power line carrier signal is too low, which causes the disconnector to fail to communicate with the outside.
  • the present invention provides an implementation method.
  • the switch sends the first data packet, if the power bus current is less than a current threshold, the discharge module 15 is turned on to increase the discharge of the output unit of the shutdown module. current to enhance the strength of the current ripple signal. For example, by turning on the bleeder module 15, an additional 5-10mA output current can be provided to the switch.
  • the switch also includes a freewheeling tube, which is connected in parallel at both ends of the output unit 123, and the switching tube 1221 forms a switching unit 122.
  • the control module or the photovoltaic module fails, Provides a bypass path for the power bus current.
  • the freewheeling tube can be realized by a diode.
  • the switch takes auxiliary power from the photovoltaic module corresponding to the input terminal 10 to supply power to the control module 13, when the switch is in normal operation mode, when the maximum output current of the photovoltaic module is smaller than the power bus current, for example, the photovoltaic module is affected Under shadow and dust occlusion, and working conditions such as large attenuation, the output voltage of the photovoltaic module will be gradually pulled down to zero, resulting in the interruption of the auxiliary power supply and the power failure of the control module 13 .
  • the switch tube 1221 is usually disconnected, and the power bus current flows through the freewheel tube of the switch module 122. The operating data cannot be coupled to the power bus through the high-frequency switching action of the switching tube 1221.
  • the present invention improves on the basis of the first embodiment, and proposes the shutdown of the second embodiment. device.
  • the freewheeling tube of the shut-off module 12 is realized by a switch tube, and its type is, for example, IGBT, MOSFET, etc., when the photovoltaic module is shaded by shadows, dust, and attenuation is large, etc.
  • the high-frequency switching action of the freewheeling tube is used to couple the communication data such as the operating data of the switch to the power bus to realize the communication sending function of the switch.
  • Fig. 4 shows a system block diagram of a switch according to a second embodiment of the present invention.
  • the freewheeling tube 1222 is a switching tube, which provides a bypass channel for the power bus current.
  • the control module 13 modulates a freewheeling control signal and the first communication signal to generate a second composite control signal, and the second composite control signal controls
  • the freewheeling tube 1222 works in a high-frequency switching state to superimpose the current ripple signal including the first communication signal on the power bus, wherein the freewheeling control signal is used to control the freewheeling tube 1222 On and off.
  • the monitoring unit 133 monitors the input voltage Vin of the switch, and outputs an input state detection signal to the power control unit 131 .
  • the power control unit 131 generates a freewheel control signal according to the input state detection signal, the operating mode of the switch and the data transmission state signal.
  • the power control unit 131 also generates a power control signal according to the input state detection signal, the operating mode of the switch, the data transmission state signal and the power bus current.
  • the magnitude of the power control signal is related to the current of the power bus, and the freewheeling control signal is a set value.
  • the modulation unit 132 modulates the power control signal and the first communication signal, and modulates the freewheeling control signal and the first communication signal to generate a corresponding first composite control signal and a second composite control signal, wherein the first composite control signal
  • the duty ratio of the signal is determined by the power bus current, and the duty ratio of the second composite control signal is a preset value.
  • the driving unit 136 respectively performs driving processing on the first composite control signal and the second composite control signal to obtain the first driving signal and the second driving signal.
  • the first driving signal controls the switching tube 1221
  • the second driving signal controls the freewheeling tube 1222 .
  • the monitoring unit 133 when the monitoring unit 133 detects that the input voltage Vin of the switch is lower than a voltage threshold, it determines that the input state of the input terminal 10 of the switch is abnormal, otherwise it is normal.
  • the power control unit 131 When the input state of the switch input terminal 10 is abnormal, the power control unit 131 outputs a power control signal to control the switch tube 1221 to be in the off state, and outputs a freewheel control signal to control the freewheel tube 1222 to be in the normal on state or the high frequency switch state
  • the power control signal output by the power control unit 131 controls the switch tube 1221 to close, and the output freewheel control signal controls the freewheel tube 1222 to turn off.
  • the second preset time is set to 5 minutes.
  • the third preset time is set to 100ms.
  • the initial operation mode of the circuit breaker after power-on is the safe disconnection mode
  • the integrated control unit 134 when the integrated control unit 134 receives the operation permission command, it switches the operation mode of the circuit breaker to the normal operation mode.
  • the comprehensive control unit 134 does not receive the allowable operation command after the first preset time, or receives the fast shutdown command, it switches the operation mode of the circuit breaker to the safe disconnection mode.
  • the switch is in the normal operation mode, if the integrated control unit 134 receives the data collection instruction, it packs the operation data of the switch into a first data packet and sends it to the protocol processing unit 135 .
  • the protocol processing unit 135 encapsulates the first data packet into a first communication signal, sends it to the modulation unit 132, and sets the data sending status signal to a busy state. At this time, if the input state of the switch input terminal 10 is normal, the power control unit 131 adjusts the magnitude of the power control signal according to the power bus current.
  • the modulation unit 132 modulates the first communication signal and the power control signal into a first composite control signal, the first composite control signal controls the switching tube 1221 to work in a high-frequency switching state, and the second composite control signal controls the freewheeling tube 1222 to be in an off state .
  • the protocol processing unit 135 sets the data sending status signal to an idle state, and the power control unit 131 adjusts the power control signal to a first preset value, and at this time, the first composite control signal controls the switching tube 1221 Working in the normally-on state, the second composite control signal controls the freewheeling tube 1222 to remain in the disconnected state; if the input state of the switch input terminal 10 is in an abnormal state, the modulation unit 132 converts the first communication signal and the freewheeling control signal Modulation generates a second composite control signal, the second composite control signal controls the freewheeling tube 1222 to work in a high-frequency switching state, and the first composite control signal controls the switching tube 1221 to be in an off state; when the first data packet is sent, the second The composite control signal controls the state of the freewheel tube 1222 to switch to the normally on state. When the operating mode of the switch is the safe disconnection mode, the first composite control signal controls the switch tube 1221 to be in the off state, and the second composite control signal controls the freewheel tube
  • the second composite control signal controls the freewheel tube 1222 to work in a high-frequency switching state, and a corresponding fundamental voltage ripple is generated on the output terminal 11 of the circuit breaker.
  • a corresponding fundamental current ripple will be generated on the power bus, thereby coupling the first communication signal containing operating data to the power bus, and generating a current ripple carrying operating data on the power bus Signal to realize the purpose of the switch to send data to the outside.
  • the principle is the same as that of the first embodiment of the present invention, and will not be repeated here.
  • the switch tube 1221 is used to send data. The principle is the same as that of the first embodiment, and will not be repeated here.
  • the switching tube 1221 and the freewheeling tube 1222 are in the disconnected state, the photovoltaic module connected to the input terminal 10 is disconnected from the power bus, the output of the photovoltaic module is in an open state, and the output power is close to zero , the output voltage and power of the switch are limited.
  • the switch tube 1221 When the breaker is in the normal operation mode, and the input state of the input terminal 10 of the breaker is in the normal state, the switch tube 1221 is in the normally-on state or the high-frequency switching state, the freewheel tube 1222 is in the disconnected state, and the input terminal 10 is connected to The input photovoltaic module is connected with the power bus, and the output power of the photovoltaic module is controlled by the power bus current and the duty ratio of the first composite control signal.
  • the switch When the switch is in normal operation mode and the input state of the input terminal 10 of the switch is abnormal, the switch tube 1221 is in the disconnected state, the photovoltaic module connected to the input terminal 10 and the power bus are disconnected, and the freewheel tube 1222 In the conduction state, the power bus current passes through the freewheel tube 1222.
  • the switch When the switch is sending data, the freewheel tube 1222 is in a high-frequency switching state, coupling the operating data to be sent by the switch to the power bus.
  • the switch tube 1221 can be located between the high potential end of the input end 10 and the high potential end of the output end 11, or between the low potential end of the input end 10 and the low potential end of the output end 11 In this embodiment, the location between the low potential ends is taken as an example for illustration.
  • Fig. 5 shows a schematic block diagram of the modulation unit 132 of the switch in the second embodiment of the present invention
  • the modulation unit 132 includes a selection switch S, a first comparator U1 and a second comparator U2, the first comparator U1 One input terminal receives the power control signal, the second input terminal is connected to the first terminal of the selection switch S, and the output terminal of the first comparator U1 outputs the first composite control signal.
  • the first input terminal of the second comparator U2 receives the freewheeling control signal, the second input terminal is connected to the first terminal of the selection switch S, and the output terminal of the second comparator U2 outputs the second composite control signal.
  • the first end of the selection switch S receives the carrier signal of the mark frequency Fm, and the second end receives the carrier signal of the spatial frequency Fs.
  • the first communication signal controls the selection switch S1 to select carrier signals of different frequencies. When the bit of the first communication signal is "1", the carrier signal of the mark frequency Fm is selected. When the bit of the first communication signal is "0", the selection Carrier signal of spatial frequency Fs.
  • the power control signal is compared with the carrier signal to obtain a first composite control signal; the freewheel control signal is compared with the carrier signal to obtain a second composite control signal.
  • the first composite control signal can control the switch tube 1221 to work in the high-frequency switching state
  • the second composite control signal controls the freewheel tube 1222 to be in the disconnected state
  • the first composite control signal The duty cycle of the control signal determines the voltage ripple of the input and output voltages, thus indirectly controlling the output power of the photovoltaic module.
  • the first composite control signal controls the switch tube 1221 to be in an off state
  • the second composite control signal controls the freewheel tube 1222 to be in a normal-on state or a high-frequency switch state.
  • the duty cycle of the second composite control signal is set to 50%.
  • this embodiment controls the output through the modulation of the freewheel tube of the switch , control the freewheeling tube to work in the high-frequency switching state, realize the data transmission of the breaker under abnormal working conditions, and improve the environmental applicability of the breaker.
  • the present invention provides a communication method for a circuit breaker, which can be applied to the above circuit breaker, but the present invention is not limited thereto.
  • the communication method in the embodiment of the present invention can be applied to any other circuit breaker that can apply the present invention .
  • Communication methods for disconnectors include:
  • Modulating a power control signal with the first communication signal to generate a first composite control signal the power control signal is used to adjust the output power of the DC power supply coupled to the input terminal 10 of the switch;
  • the first composite control signal controls the switching tube 1221 of the switch to work in a high-frequency switching state, so as to superimpose the current ripple signal including the first communication signal on the power bus.
  • the switch Collect and obtain the operating data of the circuit breaker, pack the operating data of the circuit breaker into a first data packet, and package the first data packet into a first communication signal according to a predetermined communication protocol.
  • the switch generates a power control signal according to the power bus current, modulates the first communication signal and the power control signal, and generates a first composite control signal.
  • the first composite control signal controls the switching tube 1221 to perform high-frequency switching operations.
  • the switching tube 1221 performs high-frequency switching action under the control of the first composite control signal, so that a corresponding fundamental voltage ripple is generated on the output terminal of the switch.
  • the power bus Under the excitation of the fundamental voltage ripple, the power bus The corresponding fundamental current ripple is generated, that is, the current ripple signal carrying the operating data is generated on the power bus to realize the sending function of the communication data of the switch.
  • the size of the power control signal is adjusted according to the power bus current of the switch, and then the duty ratio of the first composite control signal is controlled, so that the peak value of the ripple of the input voltage at the input terminal of the switch is between within a preset ripple threshold.
  • the duty cycle of the first composite control signal is positively correlated with the power bus current, the greater the power bus current, the larger the duty cycle, and vice versa.
  • the communication method also includes:
  • a freewheel control signal which is used to control the opening and closing of the freewheel tube of the shut-off device
  • the first composite control signal controls the switching tube 1221 to be disconnected, and a freewheel control signal is modulated with the first communication signal to generate a second composite control signal.
  • the control signal controls the freewheel tube 1222 to work in a high-frequency switching state, so as to superimpose the current ripple signal including the first communication signal on the power bus.
  • the switch When the switch is in the normal operation mode, if it is detected that the input voltage of the switch is lower than the voltage threshold, it is determined that the input state of the input terminal of the switch is abnormal.
  • the first communication signal and the freewheeling control signal are modulated to generate a second composite control signal
  • the second composite control signal controls the freewheeling tube 1222 to work in a high-frequency switching state
  • the first composite control signal controls The switch tube 1221 is in the off state, and the corresponding fundamental voltage ripple is generated on the output terminal 11 of the switch, and the corresponding fundamental current ripple is generated on the power bus, so that the first
  • the communication signal is coupled to the power bus to realize the purpose of the circuit breaker sending data to the outside when the input terminal is abnormal.
  • the second composite control signal controls the state of the freewheel tube 1222 to switch to the normally on state.
  • Fig. 6 shows the system block diagram of the disconnector of the third embodiment of the present invention, and the disconnector comprises:
  • the first input terminal 20 is used for coupling the first DC power supply
  • the output terminal 11 is used for coupling the power bus
  • the first shutdown module 22 is connected to the first input terminal 20, the first shutdown module 22 includes a first switch tube 2221, and the first switch tube 2221 is used to control the first DC power source coupled to the first input terminal 20 Output Power;
  • At least one second shutdown module 32 connected to the second input terminal 30, the second shutdown module 32 includes a second switch tube 3221, the second switch tube 3221 is used to control the second DC power source coupled to the second input terminal 30 output power;
  • the first shutdown module 22 and the second shutdown module 32 are connected in series and connected to the output terminal 11;
  • the control module 13 is configured to modulate a power control signal and the first communication signal to generate a first composite control signal, wherein the power control signal adjusts the output power of the first DC power source coupled to the first input terminal 20, the second A composite control signal controls the first switching tube 2221 to work in a high-frequency switching state, so as to superimpose a current ripple signal including the first communication signal on the power bus;
  • the control module 13 is further configured to generate a switch control signal for controlling the working state of the second switch tube 3221 .
  • the first shutdown module 22 also includes a first input unit 221 coupled to the first input terminal 20 and a first output unit 223 coupled to the output terminal 11, the first input unit 221 includes a first input capacitor Cin1 for The input voltage Vin1 of the first input terminal 20 of the switch is stabilized.
  • the first shut-off module 22 also includes a freewheeling tube connected in parallel to both ends of the first output unit 223 , and forms the first switching unit 222 with the first switching tube 2221 .
  • the first output unit 223 includes a first output capacitor Co1 for stabilizing the output voltage of the switch.
  • the second shutdown module 32 also includes a second input unit 321 coupled to the second input terminal 30 and a second output unit 323 coupled to the output terminal 11, the second input unit 321 includes a second input capacitor Cin2 for The input voltage Vin2 of the second input terminal 30 of the switch is stabilized.
  • the second shut-off module 32 also includes a freewheeling tube connected in parallel to both ends of the second output unit 323 , and forms the second switching unit 322 with the second switching tube 3221 .
  • the second output unit 323 includes a second output capacitor Co2 for stabilizing the output voltage of the switch.
  • the second shutdown module 32 is connected in series with the high potential output terminal or the low potential output terminal of the first shutdown module 22 .
  • the second shutdown module 32 is connected in series with the high potential output terminal of the first shutdown module 22 for illustration.
  • the working mode of the first shut-off module 22 is the same as that of the shut-off module in the first embodiment, the similarities will not be repeated, and only the differences will be introduced here.
  • control module 13 further includes a switch control unit 138, configured to generate a switch control signal for controlling the working state of the second switch tube 3221 according to the operating mode of the switch, and the second switch tube 3221
  • the working state includes disconnected state and normally connected state.
  • the modes of the disconnector include safe-off mode and normal operation mode.
  • the initial operation mode of the disconnector after power-on is the safe disconnection mode, and when the integrated control unit 134 receives the permission operation instruction, the operation mode of the disconnector is switched to the normal operation mode.
  • the comprehensive control unit 134 does not receive the allowable operation command after the first preset time, or receives the fast shutdown command, it switches the operation mode of the circuit breaker to the safe disconnection mode.
  • the switch when the switch is in the normal operation mode, if the integrated control unit 134 receives the data acquisition instruction, it will pack the operation data of the switch into the first data packet and send it to the protocol processing unit 135.
  • the protocol processing unit 135 encapsulates the first data packet into a first communication signal, and sets the data sending status signal to a busy status.
  • the power control unit 131 adjusts the magnitude of the power control signal according to the power bus current.
  • the modulation unit 132 modulates the first communication signal and the power control signal to generate a first composite control signal. At this time, the first composite control signal controls the first switching tube 2221 to work in a high-frequency switching state, and the switching control signal controls the second switching tube 3221 is normally on.
  • the protocol processing unit 135 sets the data transmission state signal to an idle state, and the power control unit 131 adjusts the power control signal to a first preset value, and at this time, the first composite control signal controls the first switch
  • the tube 2221 works in the normally-on state, and the switch control signal controls the second switch tube 3221 to keep in the normally-on state.
  • the power control unit 131 adjusts the power control signal to the second preset value.
  • the first composite control signal controls the first switch tube 2221 to work in the off state, and the switch control signal controls The working state of the second switching tube 3221 is an off state.
  • the first switch tube 2221 and the second switch tube 3221 are both in the off state, the connection between the photovoltaic module connected to the first input terminal 20 and the power bus is disconnected, and the second input terminal 30 The connection between the connected photovoltaic module and the power bus is disconnected, the output of the photovoltaic module is in an open state, the output power is close to zero, and the output voltage and power of the switch are in a limited state.
  • the first switching tube 2221 When the switch is in the normal operation mode, the first switching tube 2221 is in the normally-on state or the high-frequency switching state, the second switching tube 3221 is in the normally-on state, the photovoltaic module connected to the first input terminal 20 is connected to the power bus, and The photovoltaic module connected to the second input terminal 30 is connected to the power bus, and the output power of the photovoltaic module connected to the first input terminal 20 is controlled by both the power bus current and the duty ratio of the first composite control signal. The output power of the photovoltaic module connected to terminal 30 is controlled by the power bus current.
  • the first switch tube 2221 can be located between the high potential end of the first input end 20 and the high potential end of the output end 11, or between the low potential end of the first input end 20 and the output end.
  • the second switch tube 3221 can be located between the high potential end of the second input end 30 and the high potential end of the output end 11, or between the low potential end of the second input end 30 and the output end.
  • this embodiment is described as being between the high potential terminals as an example.
  • the switcher of this embodiment includes multiple input terminals, which is a multi-input topology, and the switching tube corresponding to any input terminal can be selected to work in a high-frequency switching state, so as to realize the coupling of the operating data of the switcher to the power bus.
  • multiple switching tubes share one control module, which can improve the integration and power density of the switch, and greatly reduce the production cost of the product.
  • the disconnector is connected with multiple photovoltaic modules.
  • the first shutdown module 22 that performs data transmission is connected
  • the power bus current is equal to the output current of the first photovoltaic component
  • the duty ratio of the first composite control signal is adjusted according to the power bus current.
  • the output current of the first photovoltaic module is lower than the power bus current, the output voltage of the first photovoltaic module is short-circuited to zero, if the same duty cycle control scheme as in the above-mentioned embodiment is adopted, the strength of the power line carrier signal generated on the power bus will be relatively weak, resulting in data transmission failure. Detailed description will be given below.
  • the principle that the switch implements the first communication signal sending function through the high-frequency switching action of the first switching tube 2221 is described as follows.
  • the output current I PV1 of the first photovoltaic component charges the first input capacitor Cin1, and the first input capacitor Cin1 is charged.
  • An input voltage Vin1 across an input capacitor Cin1 is boosted.
  • the output current I PV1 of the first photovoltaic module is equal to the power bus current I, and the input voltage Vin1 of the first shut-off module 22 rises linearly during this period, and its overcharge voltage ⁇ Vin1 is shown in formula (3):
  • ⁇ Vin1 (I ⁇ (1-D) ⁇ T)/C in1 (3);
  • I is the power bus current
  • T is the period of the first composite control signal
  • D is the duty cycle of the first composite control signal
  • C in1 is the capacitance of the first input capacitor Cin1 .
  • ⁇ Vo1 (I ⁇ (1-D) ⁇ T)/C o1 (4);
  • C o1 is the capacitance of the second output capacitor Co1.
  • the output voltage Vo of the shut-off device is the sum of the output voltage Vo1 of the first shut-off module 22 and the output voltage Vo2 of the second shut-off module 32.
  • the output voltage Vo contains rich high-frequency switching tube harmonics.
  • the fundamental wave component contained in the output voltage of the circuit breaker is modulated according to the first communication signal containing the operation data of the circuit breaker, and the power line carrier signal carrying the first communication signal can be injected into the power bus, which can To realize the data transmission of the switch, in this embodiment, the power line carrier signal is the fundamental component of the current ripple signal, that is, the fundamental current ripple.
  • the duty ratio D of the first composite control signal is calculated according to the power bus current I, and the first switching tube 2221 performs high-frequency switching action under the control of the first composite control signal.
  • the corresponding fundamental voltage ripple will be generated on the output terminal 11 of the breaker.
  • the corresponding fundamental current ripple will be generated on the power bus, that is, the power bus will generate a
  • the current ripple signal realizes the sending function of the communication data of the circuit breaker.
  • the output current IPV1 of the first photovoltaic component is smaller than the power bus current I, that is, the first When the input state of the first input terminal 20 is abnormal, the freewheeling tube is turned on, and the power bus current I flows through the first photovoltaic module and the freewheeling tube respectively. At this time, the input voltage Vin1 of the first shutdown module 22 is pulled down to 0, That is, if the duty cycle scheme of the above-mentioned embodiment is adopted, the strength of the power line carrier signal generated on the power bus will be relatively weak, resulting in failure of data transmission.
  • the present invention proposes the disconnector of the fourth embodiment.
  • Fig. 8 shows the system block diagram of the switch of the fourth embodiment of the present invention.
  • the switching tube 2221 when data is sent, the switching tube 2221 is controlled to work in the high-frequency switching state through the first composite control signal, so as to The power line carrier signal is superimposed on the power bus.
  • the control module 13 also controls the duty cycle of the first composite control signal according to the input voltage Vin1 of the first shutdown module 22 .
  • the control module 13 controls the first composite control signal according to the input voltage Vin1 of the first shutdown module 22 during data transmission. duty cycle.
  • the control module 13 further includes a voltage control unit 139 and a selection unit 140 , and the voltage control unit 139 generates a voltage control signal according to the input voltage Vin1 of the first shutdown module 22 .
  • the selection unit 140 is connected to the power control unit 131 and the voltage control unit 139 respectively, and selects the output power control signal or the voltage control signal to the modulation unit 132 according to the input state detection signal and the data transmission state signal of the first input terminal 20 .
  • the selection unit 140 selects the output power control signal, and the modulation unit 132 modulates the first communication signal and the power control signal to generate The first composite control signal.
  • the selection unit 140 selects the output voltage control signal, and the modulation unit 132 modulates the first communication signal and the voltage control signal to generate the first composite control signal.
  • the selection unit 140 selects the output power control signal, and the modulation unit 132 modulates the first communication signal and the power control signal to generate a first composite control signal.
  • the switch when the switch is in the normal operation mode, if the integrated control unit 134 receives the data acquisition instruction, it will pack the operation data of the switch into the first data packet and send it to the protocol processing unit 135.
  • the protocol processing unit 135 encapsulates the first data packet into a first communication signal, and sets the data sending status signal to a busy status.
  • the power control unit 131 adjusts the magnitude of the power control signal according to the power bus current.
  • the selection unit 140 selects to output the power control signal to the modulation unit 132 .
  • the modulation unit 132 modulates the first communication signal and the power control signal to generate a first composite control signal.
  • the first composite control signal controls the first switching tube 2221 to work in a high-frequency switching state, and the switching control signal controls the second switching tube 3221 is normally on.
  • the protocol processing unit 135 sets the data transmission state signal to an idle state, and the power control unit 131 adjusts the power control signal to a first preset value, and at this time, the first composite control signal controls the first switch
  • the tube 2221 works in the normally-on state, and the switch control signal controls the second switch tube 3221 to keep in the normally-on state.
  • the power control unit 131 adjusts the power control signal to the second preset value.
  • the first composite control signal controls the first switch tube 2221 to work in the off state, and the switch control signal controls The working state of the second switching tube 3221 is an off state.
  • the switch when the switch is in the normal operation mode, if the integrated control unit 134 receives the data acquisition instruction, it will pack the operation data of the switch into the first data packet and send it to the protocol processing unit 135.
  • the protocol processing unit 135 encapsulates the first data packet into a first communication signal, and sets the data sending status signal to a busy status.
  • the voltage control unit 139 adjusts the magnitude of the voltage control signal according to the input voltage Vin1 of the first shutdown module 22, and the selection unit 140 selects the output voltage control signal to the modulation unit 132.
  • the modulation unit 132 modulates the first communication signal and the voltage control signal into a first composite control signal, the first composite control signal controls the first switch tube 2221 to work in a high-frequency switching state, and the switch control signal controls the second switch tube 3221 to be normally on state.
  • the protocol processing unit 135 sets the data sending state signal to an idle state, and the selection unit 140 selects to output the power control signal to the modulation unit 132 .
  • the power control unit 131 adjusts the power control signal to a first preset value.
  • the first composite control signal controls the first switch tube 2221 to work in a normally-on state
  • the switch control signal controls the second switch tube 3221 to maintain a normally-on state.
  • the power control unit 131 adjusts the power control signal to the second preset value.
  • the first composite control signal controls the first switch tube 2221 to work in the off state
  • the switch control signal controls The working state of the second switching tube 3221 is an off state.
  • the monitoring unit 133 when the monitoring unit 133 detects that the input voltage Vin1 of the first shut-off module 22 is less than a corresponding preset voltage threshold, it determines that the input state of the first input terminal 20 of the shut-off device is Otherwise, it is normal, and an input state detection signal representing the input state of the first input terminal 20 is output.
  • the duty ratio of the first composite control signal is controlled according to the input voltage Vin1 of the first shutdown module 22 .
  • the duty cycle of the first composite control signal is increased so that the input voltage of the first input terminal 20 of the shut-off device
  • the peak value of the ripple is within a preset ripple threshold; when the peak value of the input voltage Vin1 of the first shutdown module 22 is lower than the first reference voltage, the duty cycle of the first composite control signal is reduced to increase the power line
  • the strength of the carrier signal meets the signal strength requirements in data transmission to prevent data transmission failure.
  • the duty ratio of the first composite control signal is controlled according to the input voltage Vin1 of the first shutdown module 22 .
  • the average value of the input voltage Vin1 of the first shut-off module 22 is greater than the preset second reference voltage, increase the duty cycle of the first composite control signal so that the input voltage of the first input terminal 20 of the shut-off device
  • the peak value of the ripple is within a preset ripple threshold; when the average value of the input voltage Vin1 of the first shutdown module 22 is less than the second reference voltage, the duty cycle of the first composite control signal is reduced to Increase the strength of the power line carrier signal to meet the signal strength requirements in data transmission and prevent data transmission failure.
  • the voltage control unit 139 includes an error amplifier and a controller, and the error amplifier is used to obtain an error amplification value between the input voltage Vin1 of the first shutdown module 22 and a reference voltage.
  • the controller generates a voltage control signal according to the error amplification value.
  • the controller is, for example, a PI controller or a Bang-Bang controller.
  • the reference voltage is the first reference voltage, or the second reference voltage.
  • the error amplifier calculates an error amplification value between a peak value ⁇ V in1_peak of the input voltage Vin and a first reference voltage or an error amplification value between an average value V in1_ave of the input voltage Vin and a second reference voltage.
  • the sampling resistor Rcs is connected in series between the output terminals of the second shutdown module 32 and the first shutdown module 22, and the power bus current I is obtained according to the voltage at both ends of the sampling resistor Rcs.
  • the connection point between the first shut-off module 22 and the sampling resistor Rcs is used as a common ground.
  • Fig. 9 is a waveform diagram of the input and output voltages of the first shutdown module of the switch according to an embodiment of the present invention when sending data.
  • the first switching tube 2221 When the first photovoltaic module is abnormal, the first switching tube 2221 During the disconnection period, the output current IPV1 of the first photovoltaic module charges the first input capacitor Cin1, the input voltage Vin1 at both ends of the first input capacitor Cin1 is raised, and the input voltage Vin1 of the cut-off device rises linearly during this period, and the overcharge voltage ⁇ Vin1 is shown in formula (3).
  • the drop voltage ⁇ Vo1 on the first output capacitor Co1 is:
  • ⁇ Vo1 sqrt(C in1 /(C o1 +C in1 ))* ⁇ Vin1 (5);
  • the strength of the current ripple signal is related to the output current IPV1 of the first photovoltaic module, that is, to the input current IPV1 of the first shutdown module 22, and can be adjusted according to the input current of the first shutdown module 22.
  • the magnitude of the duty cycle of the first composite control signal, that is, the duty cycle is calculated according to the input current of the first shutdown module 22 .
  • the input current of the first shut-off module 22 is not easy to detect. According to the voltage and current characteristics of the photovoltaic module, it is possible to adjust the first compound current by detecting the input voltage Vin1 of the first shut-off module 22 according to the input voltage Vin1. The duty cycle of the control signal.
  • the peak value ⁇ V in1_peak of the input voltage of the first shutdown module 22 is:
  • the peak value ⁇ V o1_peak of the drop voltage ⁇ Vo1 on the first output capacitor Co1 is:
  • ⁇ T is the time for the output voltage Vo1 to drop
  • the peak value ⁇ V in1_peak of the input voltage Vin1 when the peak value ⁇ V in1_peak of the input voltage Vin1 is greater than the first reference voltage, increase the duty cycle; when the peak value ⁇ V in1_peak of the input voltage Vin1 is lower than the first reference voltage, reduce the duty cycle to increase the drop
  • the peak value of the voltage ⁇ Vo1 increases the strength of the current ripple signal to meet the requirements of the carrier signal strength in data transmission and prevent data transmission failure.
  • the average value V in1_ave of the input voltage Vin1 of the first shutdown module 22 is:
  • the duty ratio of the first composite control signal can be adjusted according to the average value V in1_ave of the input voltage V in1 . Specifically, when the average value V in1_ave of the input voltage V in1 is greater than the second reference voltage, increase the duty cycle, and when the average value V in1_ave of the input voltage V in1 is lower than the second reference voltage, decrease the duty cycle, Increase the strength of the power line carrier signal to meet the requirements of the carrier signal strength in data transmission and prevent data transmission failure.
  • the second photovoltaic component connected to the second shutdown module 32 provides power for the control module 13 .
  • the number of shut-off modules in the shut-off device can be any number such as 3, 4, 5, etc., and the input end of the corresponding shut-off unit can be connected to 3, 4, 5 photovoltaic modules, etc., for
  • the output of the shutdown module corresponding to the photovoltaic component that supplies power to the control module is connected in series with the output of the shutdown module for sending data.
  • the first shut-off module 22 includes a freewheel tube 2222, and the freewheel tube 2222 is a switching tube.
  • the first composite control signal controls the first switching tube 2221 to work in the high-frequency switching state, and controls the freewheeling tube 2222 to be in the off state;
  • the first switching tube 2221 and the freewheeling tube 2222 are controlled to be closed to provide a freewheeling channel for the power bus current.
  • the present invention provides a communication method for a switch, which can be applied to the above switch.
  • Communication methods for the disconnector include:
  • Modulating a power control signal with the first communication signal to generate a first composite control signal the power control signal is used to adjust the output power of the first DC power source coupled to the first input terminal 20 of the switch;
  • the first composite control signal controls the first switching tube 2221 of the first input terminal 20 of the switch to work in a high-frequency switching state, so as to superimpose the current ripple signal including the first communication signal on the power bus;
  • a switch control signal is provided, and the switch control signal is used to control the working state of the second switch tube at the second input end of the switch.
  • the communication method of the circuit breaker further includes: adjusting the size of the power control signal according to the power bus current of the circuit breaker, and then controlling the duty ratio of the first composite control signal, so that the circuit breaker The peak value of the ripple of the input voltage at the input terminal is within a preset ripple threshold.
  • the communication method of the switch further includes: when transmitting data, generating a power control signal according to the power bus current, modulating the power control signal and the first communication signal to generate a first composite control signal,
  • the first composite control signal controls the first switch tube 2221 of the switch to work in the high-frequency switching state, and the switch control signal controls the second switch tube 3221 of the switch to be in the normally-on state; when the data transmission is completed, the first composite control The signal controls the first switch tube 2221 to work in a normally-on state, and the switch control signal controls the second switch tube 3221 to maintain a normally-on state.
  • the first composite control signal is controlled according to the input voltage of the first shutdown module 22 of the switch. duty cycle.
  • a voltage control signal is generated according to the input voltage of the first shutdown module 22, and the first communication signal and the voltage control signal are modulated to generate a first composite control signal.
  • the first communication signal and the power control signal are modulated to generate the first composite control signal;
  • the first communication signal and the voltage control signal are modulated to generate a first composite control signal, and the first composite control signal controls the first switching tube 2221 of the switch to work in a high-frequency switching state, and the switching control The signal controls the second switch tube 3221 of the switch to be in the normally-on state.
  • the first communication signal and the power control signal are modulated to generate a first composite control signal.
  • the first composite control signal controls the first
  • the switch tube 2221 works in the normally-on state
  • the switch control signal controls the second switch tube 3221 to keep in the normally-on state.
  • the communication method of the switch further includes: when the peak value of the input voltage of the first shutdown module 22 is greater than or equal to the preset first reference voltage, increasing the duty cycle of the first composite control signal Duty ratio, when the peak value of the input voltage of the first shutdown module 22 is smaller than the first reference voltage, the duty ratio of the first composite control signal is reduced.
  • the communication method of the switch further includes: when the average value of the input voltage of the first shutdown module 22 is greater than or equal to the preset second reference voltage, increasing the duty cycle of the first composite control signal Duty ratio, when the average value of the input voltage of the first shut-off module 22 is smaller than the second reference voltage, the duty ratio of the first composite control signal is reduced.
  • the present invention provides a fast shutdown photovoltaic system
  • the system includes a plurality of photovoltaic modules 40, a plurality of disconnectors 41, a main controller 42, a photovoltaic inverter 43 and Grid-connected switch 44, each disconnector 41 is connected to the first photovoltaic module and the second photovoltaic module, multiple disconnectors 41 are connected in series to a power bus, and the power bus is connected to the DC input port of the photovoltaic inverter 43
  • the switch 41 includes a first input terminal and at least one second input terminal, a first shutdown module connected to the first input terminal, a second shutdown module connected to the second input terminal, an output terminal and a control module
  • the first shutdown module includes a first switch tube
  • the second shutdown module includes a second switch tube
  • the switch 41 is configured to modulate the power control signal and the first communication signal, and modulate to generate a first composite control signal, the power control signal adjusts the output power of the first DC power supply coupled to the first input terminal,
  • the first composite control signal controls the first switching tube to work in a high-frequency switching state, so as to superimpose the current ripple signal including the first communication signal on the power bus, and the switch is also used according to The operating mode of the switch generates a switch control signal to control the working state of the second switch tube;
  • the main controller 42 is used to extract the current ripple signal in the power bus, perform demodulation and analysis processing, and obtain the first communication signal sent by the switch.
  • the main controller 42 includes a power line carrier transceiver and a current transformer, extracts the power line carrier signal (that is, the current ripple signal) coupled to the power bus by the switch 41 through the current transformer, and passes through the solution of the power line carrier transceiver.
  • the first data packet sent by the switch 41 is obtained through adjustment and analysis processing, and the first data packet includes the operation data of the switch 41.
  • the second data packet sent by the main controller 42 including the control command of the shut-off device is encapsulated and modulated by the power line carrier transceiver, and then coupled to the power bus through the current transformer, and transmitted to each power bus through the power bus. Switch 41.
  • the master controller 42 communicates point-to-point with each switch 41 in a master-slave polling manner.
  • the master controller 42 periodically sends control commands to collect operating data of the switch 41 and controls the operation mode of the switch.
  • the control instruction of the main controller 42 includes an operation permission instruction, which is used to control the operation state of the photovoltaic system.
  • each switch 41 When the allowable operation command is normally sent, if each switch 41 normally receives the allowable run command, each switch 41 is in the normal operation mode, and the switching tube of the switch is in the normal-on state or high-frequency switching state, and the input photovoltaic
  • the components are normally connected in series to the power bus, and the photovoltaic system is in a normal operating state; when the operation command is allowed to stop sending for a certain period of time, each switch 41 switches to the safe disconnection mode, and its switch tube is in the off state, and the switch 41
  • the connection between the photovoltaic module 40 at the input end of the power bus and the power bus is disconnected, the voltage of the power bus is quickly discharged to a safe voltage within a specified time, and the photovoltaic system is in a safe disconnection mode.
  • the switch 41 extracts the power line carrier signal sent by the main controller 42 to the power bus through the internal RLC decoupling circuit, and obtains the polling command sent by the main controller through conditioning, demodulation and analysis processing. If the collection address matches the address of the switch 41, the switch will generate the first composite control signal through comprehensive processing of the collected operating data by the internal protocol processing unit, power control unit, and modulation unit, and the switch of the switch 41
  • the tube receives the first composite control signal to make the switching tube work in a high-frequency switching state, and injects a power line carrier signal carrying the operating data of the switch 41 on the power bus, and is coupled to the main controller 42 through the power bus.
  • the controller 42 acquires the operating data of the circuit breaker 41 .

Abstract

本发明公开了一种关断器,包括第一输入端、第二输入端、输出端、第一关断模块、第二关断模块及控制模块,第一关断模块包括第一开关管,第一开关管控制第一输入端耦接的第一直流电源的输出功率;第二关断模块包括第二开关管,第二开关管控制第二输入端耦接的第二直流电源的输出功率;控制模块将一功率控制信号与第一通信信号进行调制,生成第一复合控制信号,功率控制信号调节第一输入端耦接的第一直流电源的输出功率,第一复合控制信号控制第一开关管工作在高频开关状态下,以在功率总线上叠加包含第一通信信号的电流纹波信号;控制模块还生成开关控制信号,控制第二开关管的工作状态。本发明可提高关断器的集成度和功率密度,降低生产成本。

Description

一种关断器、关断器的通信方法及快速关断光伏系统
本申请要求于2021年10月20日提交的申请号为PCT/CN2021/124879,发明名称为“一种关断器、关断器的通信方法及快速关断光伏系统”的PCT专利申请的优先权,其全部内容通过引用结合在本申请中。
技术领域
本发明涉及分布式光伏发电技术领域,尤其涉及一种关断器、关断器的通信方法及快速关断光伏系统。
背景技术
近年来,在光伏上下游产业链的共同努力下,光伏发电电价逐渐低于购电电价甚至传统煤电的发电成本,光伏装机容量逐年快速增长,在不久的未来将成为主要的发电来源。
组串式光伏系统由于技术成熟、转换效率高、集成度高、价格低廉等优势,在户用和工商业屋顶等分布式光伏系统以及地面电站中都得到了广泛的应用,但是当光伏系统起火时,组串式光伏系统的直流高压却给屋顶灭火带来了严重的触电风险,消防灭火极其困难,大部分情况只能任由火灾蔓延。为了解决屋顶光伏系统的灭火安全问题,2017版美国国家电气法规NEC引入了组件级快速关断功能,要求光伏阵列内部任意导体上的电压在触发快速关断功能后30s内降至80V以下,光伏阵列外部导体上的电压在30s内降至30V以下,随后UL1741标准中也加入了快速关断装置和快速关断系统的评估方法。
组串式光伏系统满足NEC 2017快速关断要求的解决方案是增加组件级快速关断设备,包括关断器和优化器,关断器由于成本较低,且大部分关断器都兼容Sunspec快速关断协议,可互相替代使用,因而在组串式光伏系统中得到了广泛的应用。
Sunspec快速关断协议是一种简单可靠的单向电力线载波通讯协议,采 用该协议的传统关断器简单、可靠、成本低廉,但是仅有接收功能,不能发送信息,无法实现组件级的监控。当关断器、组件等出现异常时,故障排查费时费力。有厂家将关断器中Sunspec快速关断协议接收器换成电力线载波收发器模块,实现了关断器的双向通讯功能,进而提供组件级监控,但是增加了不少成本,也有其他的厂家将Sunspec快速关断协议接收器替换为无线通讯收发器实现双向通讯功能,但是无线通讯在现场不是很稳定,需要中继来提升现场通讯的稳定性,增加了系统的通讯复杂度及成本。
发明内容
有鉴于此,本发明的目的在于提供一种关断器、关断器的通信方法及快速关断光伏系统,可以提高关断器的集成度和功率密度,大幅降低产品的生产成本。
为实现上述目的,本发明提供一种关断器,所述关断器包括:
第一输入端,用于耦接第一直流电源;
至少一个第二输入端,用于耦接第二直流电源;
输出端,用于耦接功率总线;
第一关断模块,与第一输入端连接,第一关断模块包括第一开关管,第一开关管用于控制第一输入端耦接的第一直流电源的输出功率;
至少一个第二关断模块,与第二输入端连接,第二关断模块包括第二开关管,第二开关管用于控制第二输入端耦接的第二直流电源的输出功率;
所述第一关断模块和至少一个第二关断模块的输出串联连接,并与所述输出端连接;
控制模块,用于将一功率控制信号与第一通信信号进行调制,生成第一复合控制信号,其中,所述功率控制信号调节第一输入端耦接的第一直流电 源的输出功率,所述第一复合控制信号控制所述第一开关管工作在高频开关状态下,以在功率总线上叠加包含所述第一通信信号的电流纹波信号;
控制模块,还用于生成开关控制信号,用以控制第二开关管的工作状态。
进一步的,所述控制模块根据功率总线电流调节所述功率控制信号的大小,进而控制所述第一复合控制信号的占空比,使关断器的输入端的输入电压的纹波峰值在一预设的纹波阈值内。
进一步的,所述第一复合控制信号的占空比和所述功率总线电流正相关,所述功率总线电流越大,所述占空比越大,反之所述占空比越小。
进一步的,所述控制模块包括:
功率控制单元,用于根据所述功率总线电流生成功率控制信号;
调制单元,用于接收所述第一通信信号和所述功率控制信号,并对所述第一通信信号和所述功率控制信号进行调制生成所述第一复合控制信号;
开关控制单元,所述开关控制单元用于生成控制所述第二开关管的工作状态的开关控制信号。
进一步的,所述控制模块还包括:
监测单元,用于采集并获取关断器的运行数据;
综合控制单元,用于将所述关断器的运行数据打包成第一数据包;
协议处理单元,用于将所述第一数据包按照预定的通信协议封装为所述第一通信信号,并发送至所述调制单元。
进一步的,当进行数据发送时,所述综合控制单元将关断器的运行数据打包成第一数据包并发送至协议处理单元,所述第一复合控制信号控制所述第一开关管工作在高频开关状态,所述开关控制信号控制所述第二开关管为 常通状态;
当数据发送完成后,所述第一复合控制信号控制第一开关管工作在常通状态,所述开关控制信号控制所述第二开关管保持为常通状态。
进一步的,所述关断器还包括信号解耦模块,将来自所述功率总线的电力线载波信号与功率总线电流进行分离,提取电力线载波信号;
所述控制模块还包括解调单元,用于将所述提取的电力线载波信号解调后得到第二通信信号;
所述协议处理单元,还用于对所述第二通信信号按照协议格式解析出第二数据包,将第二数据包传递给综合控制单元,综合控制单元对第二数据包进行解析,获取第二数据包中的控制指令,所述控制指令用于控制关断器的工作状态。
进一步的,当所述关断器第一输入端的输入状态异常,在进行数据发送时,所述控制模块根据所述第一关断模块的输入电压控制所述第一复合控制信号的占空比。
进一步的,当所述第一关断模块的输入电压的峰值大于等于预设的第一参考电压时,增大所述第一复合控制信号的占空比,当所述第一关断模块的输入电压的峰值小于所述第一参考电压时,减小所述第一复合控制信号的占空比。
进一步的,当所述第一关断模块的输入电压的均值大于等于预设的第二参考电压时,增大所述第一复合控制信号的占空比,当所述第一关断模块的输入电压的均值小于所述第二参考电压时,减小所述第一复合控制信号的占空比。
进一步的,当所述监测单元监测到所述关断器的第一关断模块的输入电压小于预设的电压阈值时,判定所述第一输入端的输入状态为异常,否则为 正常,并输出用以表示所述第一输入端的输入状态的输入状态检测信号。
进一步的,所述控制模块还包括:
电压控制单元,用于根据所述第一关断模块的输入电压产生电压控制信号;
选择单元,分别与所述功率控制单元和所述电压控制单元连接,用于根据所述输入状态检测信号,选择输出所述功率控制信号或者电压控制信号,以控制所述第一复合控制信号的占空比。
进一步的,当第一输入端的输入状态正常时,所述选择单元选择输出所述功率控制信号,所述调制单元对所述第一通信信号和所述功率控制信号进行调制,生成所述第一复合控制信号;
当第一输入端的输入状态异常,在进行数据发送时所述选择单元选择输出所述电压控制信号,所述调制单元对所述第一通信信号和所述电压控制信号进行调制,生成所述第一复合控制信号,数据发送完成时,所述选择单元选择输出所述功率控制信号。
进一步的,所述电压控制单元包括:
误差放大器,用于获取所述第一关断模块的输入电压和参考电压之间的误差放大值;
控制器,用于根据所述误差放大值产生所述电压控制信号。
进一步的,与所述第一关断模块相邻的第二关断模块所连接的第二直流电源用于向所述控制模块提供电源。
进一步的,所述关断器还包括采样电阻,所述采样电阻分别与所述第一关断模块以及与所述第一关断模块相邻的第二关断模块连接,所述采样电阻用于获取功率总线电流,所述采样电阻和所述第一关断模块之间的连接点作 为公共地。
为实现上述目的,本发明提供一种关断器的通信方法,所述方法包括:
将一功率控制信号与第一通信信号进行调制,生成第一复合控制信号,所述功率控制信号用于调节关断器的第一输入端所耦接的第一直流电源的输出功率;
所述第一复合控制信号控制所述关断器的第一输入端的第一开关管工作在高频开关状态下,以在功率总线上叠加包含所述第一通信信号的电流纹波信号;
提供一开关控制信号,所述开关控制信号用以控制所述关断器的第二输入端的第二开关管的工作状态。
进一步的,所述方法还包括:
根据关断器的功率总线电流调节所述功率控制信号的大小,进而控制所述第一复合控制信号的占空比,使关断器的输入端的输入电压的纹波峰值在一预设的纹波阈值内。
进一步的,所述方法还包括:
当进行数据发送时
当进行数据发送时,根据功率总线电流生成功率控制信号,将所述功率控制信号与所述第一通信信号调制生成所述第一复合控制信号,所述第一复合控制信号控制所述关断器的第一开关管工作在高频开关状态,所述开关控制信号控制所述关断器的第二开关管为常通状态;
当数据发送完成后,所述第一复合控制信号控制所述第一开关管工作在常通状态,所述开关控制信号控制所述第二开关管保持为常通状态。
进一步的,所述方法还包括:
当所述关断器第一输入端的输入状态异常,在进行数据发送时,根据所述关断器的第一关断模块的输入电压控制所述第一复合控制信号的占空比。
进一步的,所述方法还包括:
当所述第一关断模块的输入电压的峰值大于等于预设的第一参考电压时,增大所述第一复合控制信号的占空比,当所述第一关断模块的输入电压的峰值小于所述第一参考电压时,减小所述第一复合控制信号的占空比。
进一步的,所述方法还包括:
当所述第一关断模块的输入电压的均值大于等于预设的第二参考电压时,增大所述第一复合控制信号的占空比,当所述第一关断模块的输入电压的均值小于所述第二参考电压时,减小所述第一复合控制信号的占空比。
进一步的,所述方法还包括:
当所述关断器的第一输入端的输入状态正常时,对所述第一通信信号和所述功率控制信号进行调制,生成所述第一复合控制信号;
当所述关断器的第一输入端的输入状态异常,在进行数据发送时,根据第一关断模块的输入电压产生电压控制信号,对所述第一通信信号和所述电压控制信号进行调制生成所述第一复合控制信号,数据发送完成时,对所述第一通信信号和所述功率控制信号进行调制,生成所述第一复合控制信号。
为实现上述目的,本发明提供一种快速关断光伏系统,所述系统包括多个关断器、多个光伏组件、主控器以及光伏逆变器,每一个关断器接入第一光伏组件和第二光伏组件,多个关断器串接在一功率总线上,所述功率总线接入光伏逆变器的直流输入端口,所述关断器包括第一输入端、至少一个第二输入端、与第一输入端连接的第一关断模块、与第输入端连接的第二关断 模块、输出端以及控制模块,所述第一关断模块包括第一开关管,所述第二关断模块包括第二开关管,其中,
所述关断器,用于将功率控制信号与第一通信信号进行调制,并调制生成第一复合控制信号,所述功率控制信号调节第一输入端耦接的第一直流电源的输出功率,所述第一复合控制信号控制所述第一开关管工作在高频开关状态下,以在功率总线上叠加包含所述第一通信信号的电流纹波信号,所述关断器还用于生成开关控制信号,用以控制所述第二开关管的工作状态;
所述主控器,用于提取功率总线中的电流纹波信号,进行解调和解析处理,获取关断器发送的第一通信信号。
本发明中的关断器包括多个输入端,为多输入的拓扑结构,可以选择任意一输入端对应的关断模块的开关管工作在高频开关状态,实现将关断器的运行数据耦合至功率总线进行数据发送的目的,多个关断模块共用一个控制模块,可以提高关断器的集成度和功率密度,大幅降低产品的生产成本;在多输入端的关断器中,当用于发送数据的关断模块所连接的光伏组件异常时,根据关断模块的输入电压调节复合控制信号的占空比,增加了电力线载波信号的强度,以使在光伏组件异常时能够实现通信数据的正常发送。
附图说明
图1是根据本发明的第一实施例的关断器的系统框图;
图2是根据本发明的一个实施例的关断器进行数据发送时输入输出电压波形图;
图3是根据本发明的第一实施例的关断器的调制单元的示意框图;
图4是根据本发明的第二实施例的关断器的系统框图;
图5是根据本发明的第二实施例的关断器的调制单元的示意框图;
图6是根据本发明的第三实施例的关断器的系统框图;
图7是根据本发明的第三实施例的关断器进行数据发送时输入输出电压波形图;
图8是根据本发明的第四实施例的关断器的系统框图;
图9是根据本发明的第四实施例的关断器进行数据发送时输入输出电压波形图;
图10是根据本发明的第五实施例的关断器的系统框图;
图11是根据本发明的实施例的快速关断光伏系统的系统示意图。
具体实施方式
以下将结合附图所示的具体实施方式对本发明进行详细描述,但这些实施方式并不限制本发明,本领域的普通技术人员根据这些实施方式所做出的结构、方法、或功能上的变换均包含在本发明的保护范围内。
如图1所示的本发明一个实施例中,本发明提供一种关断器,关断器包括:
至少一个输入端10,用于耦接直流电源;
输出端11,用于耦接功率总线;
至少一个关断模块12,关断模块12对应一个输入端10,包括至少一个开关管1221,开关管1221用于控制输入端10耦接的直流电源的输出功率:
控制模块13,用于将一功率控制信号与第一通信信号进行调制,生成第一复合控制信号,其中,
功率控制信号,用于调节输入端10耦接的直流电源的输出功率;
第一复合控制信号,用于控制开关管1221工作在高频开关状态下,以在功率总线上叠加包含第一通信信号的电流纹波信号。
直流电源至少包含一个电池片,一般为一个光伏组件或两个串联的光伏组件。本发明以直流电源为光伏组件为例说明,一个输入端10对应一个光伏组件。在其他实施例中,关断模块12例如包括多个串联和/或并联连接的开关管,通过控制任意一开关管工作在高频开关状态以实现数据发送功能。
以下将以关断器包括一个输入端10、一个输出端11、一个关断模块12、一个控制模块13以及关断模块12包括一个开关管1221为例进行说明,但不以次为限。
开关管1221连接在输入端10和输出端11之间,控制输入端10耦接的光伏组件的输出功率。开关管1221可以位于输入端10的高电位端和输出端11的高电位端之间,也可以位于输入端10的低电位端和输出端11的低电位端之间,本实施例以位于低电位端之间为例说明,控制模块13与关断模块12耦接,根据第一通信信号和功率总线电流生成控制开关管1221的第一复合控制信号,第一复合控制信号调节关断器的输入端10耦接的光伏组件的输出功率,以及控制开关管1221工作在高频开关状态,以将第一通信信号耦合至功率总线并进行传输。功率总线将多个关断器的输出端串接起来接入光伏逆变器,其线路长度为数十米到数百米,回路寄生电感一般在7.8uH到269uH之间。功率总线电流受光伏逆变器控制,光伏逆变器通过调控功率总线电流来实现光伏系统中各个光伏组件的最大功率输出。
所述第一通信信号包含关断器的通信数据,所述通信数据包括关断器的运行数据等,但不以此为限,在其他实施例中,所述第一通信信号还可以包含其他任何需要发送的数据。
作为本发明的一种实现方式,控制模块13根据功率总线电流调节功率控制信号的大小,进而控制第一复合控制信号的占空比,使关断器的输入端的 输入电压的纹波峰值在一预设的纹波阈值内,从而避免光伏组件的稳态工作点大幅度波动,导致光伏组件在开关管1221进行高频的开关动作时输出功率降低的问题。第一复合控制信号的占空比和功率总线电流正相关,功率总线电流越大,占空比越大,反之占空比越小。
作为本发明的一种实现方式,关断模块12还包括一与输入端10耦接的输入单元121以及与输出端11耦接的输出单元123,输入单元121包括一输入电容Cin,用于稳定关断器的输入电压Vin。输出单元123包括一输出电容Co,用于稳定关断器的输出电压Vo。
关断器通过开关管1221的高频开关动作实现第一通信信号发送功能的原理说明如下。当开关管1221工作在高频开关状态时,在开关管1221瞬时断开期间,由于功率总线的线路寄生电感足够大,在储能惯性作用下,功率总线电流基本保持不变,输出端11的输出电压Vo线性下跌,跌落电压ΔVo如式(1)所示:
ΔVo=(I·(1-D)·T)/C o  (1);
其中,I为功率总线电流,T为第一复合控制信号的周期,D为第一复合控制信号的占空比,C o为输出电容Co的容值。
在开关管1221瞬时断开期间,光伏组件的输出电流给输入电容Cin充电,输入电容Cin两端的输入电压Vin被抬升。当光伏组件受光伏逆变器的控制工作在最大功率点,关断器的输入电压Vin小幅波动,波动值小于光伏组件的输出电压的10%时,对光伏组件的输出电流影响很小,光伏组件的输出电流可认为基本不变,近似等于功率总线电流,关断器的输入电压Vin在此期间线性上升,其过充电压ΔVin如式(2)所示:
ΔVin=(I·(1-D)·T)/C in  (2);
其中,C in为输入电容Cin的容值。
当开关管1221闭合时,输入电容Cin在开关管1221断开期间存储的能量通过开关管1221快速转移到输出电容Co,补偿输出电容Co在开关管1221关断期间泄放掉的能量,同时关断器的输入电压Vin和输出电压Vo恢复至稳态电压,光伏组件的输出电压也恢复至稳态电压,光伏逆变器仍然通过调节功率总线电流来控制光伏组件的输出电压,使其工作在最大功率点。同时关断器需要根据功率总线电流来调整占空比D,例如根据式(1)或式(2)中的比例关系进行调整,使得开关管1221关断期间,关断器的输入电压Vin的过充电压ΔVin小于光伏组件的输出电压的10%,避免光伏组件工作点偏离最大功率点较多,降低光伏组件的输出功率。
在开关管1221工作在高频开关状态时,关断器的输出电压Vo包含丰富的高频开关管谐波,对输出电压Vo进行傅里叶分解,可以得到输出电压Vo的直流分量、基波分量及各次谐波分量,其中,基波分量的频率为开关管1221的开关频率。在输出电压Vo的基波分量的激励下,功率总线产生对应的基波电流纹波。根据以上分析可知,根据包含关断器运行数据的第一通信信号对关断器的输出电压所包含的基波分量进行调制,可以在功率总线上注入携带第一通信信号的电力线载波信号,可以实现关断器数据发送功能,本实施例中,所述电力线载波信号为电流纹波信号的基波分量,即所述基波电流纹波。
作为本发明的一种实现方式,关断器输入电容Cin的典型值为1uF,输出电容Co的典型值为1uF,开关频率为100kHz,功率总线在该开关频率下的阻抗为100欧姆。当关断器的输入电压Vin为40V、功率总线电流为2A、过充电压ΔVin控制为2V,根据公式(1)、(2)得出占空比D=0.9,跌落电压ΔVo为2V,输入电压Vin和输出电压Vo的波形如图2所示。对输出电压Vo的波形进行傅里叶分解,可以得到输出电压Vo的直流分量、基波分量及各次谐波分量,其中100kHz基波分量的幅值为100mV,该输出电压Vo的基波分量在功率总线上产生幅值为1mA的基波电流纹波;当关断器的输入电压Vin 为40V、功率总线电流为10A、ΔVin控制为2V,根据公式(1)(2)得出占空比D=0.98,跌落电压ΔVo为2V,对输出电压Vo的波形进行傅里叶分解,可以得到输出电压Vo的基波分量的幅值为38mV,该输出电压Vo的基波分量在功率总线上产生幅值为0.38mA的基波电流纹波。
作为本发明的一种实现方式,所述控制模块13包括功率控制单元131和调制单元132。所述功率控制单元131根据功率总线电流生成功率控制信号,并输出至调制单元132。所述调制单元132接收第一通信信号和功率控制信号,对第一通信信号和功率控制信号进行调制,生成第一复合控制信号。第一复合控制信号控制开关管1221进行高频的开关动作。开关管1221在第一复合控制信号的控制下执行高频开关动作,使在关断器的输出端上产生相应的基波电压纹波,在该基波电压纹波的激励下,功率总线上产生相应的基波电流纹波,从而将包含运行数据的第一通信信号耦合至功率总线,在功率总线上产生携带运行数据的电流纹波信号,实现关断器数据的发送功能,不需要传统的关断器中的电力线载波收发器模块或无线通信模块,就可以实现关断器的数据发送功能。
调制单元132对接收到的功率控制信号和第一通信信号进行调制生成第一复合控制信号。基于多种成熟的调制技术对功率控制信号和第一通信信号进行调制,即对关断器的输出电压中的基波分量进行调制,从而使得功率总线中的基波电流纹波携带包含关断器的运行数据的第一通信信号。可采用的成熟调制技术有FSK(Frequency shift keying频移键控)、PSK(Phase shift keying相移键控)等等。FSK调制技术实现简单,抗噪声与抗衰减的性能较好,在中低速率数字通讯中得到了广泛的应用,比如各种窄带电力线载波通讯芯片、蓝牙、ZIGBEE等无线芯片均采用FSK调制技术,FSK调制技术有马克频率Fm(mark frequency)和空间频率Fs(space frequency)两个码元,马克频率Fm用来表示数字“1”,空间频率Fs用来表示数字“0”。
本发明以采用FSK调制技术为例说明,图3示出了的调制单元132的示 意框图,调制单元132包括选择开关S和第一比较器U1。第一比较器U1的第一输入端接收功率控制信号,第二输入端与选择开关S的第一端连接,输出端输出第一复合控制信号。选择开关S的第二端接收马克频率Fm的载波信号,第三端接收空间频率Fs的载波信号。第一通信信号控制选择开关S选择不同频率的载波信号,当第一通信信号bit为“1”时,选择马克频率Fm的载波信号,当第一通信信号bit为“0”时,选择空间频率Fs的载波信号。功率控制信号和载波信号进行比较,得到第一复合控制信号。第一复合控制信号控制开关管1221工作在高频开关状态,其频率决定输出电压Vo的基波分量的频率,相应的,也决定了电流纹波信号的基波分量的频率,第一复合控制信号的占空比决定了关断器输入/输出电压的电压纹波,从而间接控制了光伏组件的输出功率。
作为本发明的一种实现方式,所述控制模块13还包括监测单元133、综合控制单元134和协议处理单元135。所述监测单元133采集并获取关断器的运行数据,发送至综合控制单元134。所述关断器的运行数据包括关断器的输入输出电气参数和内部运行数据,其中,所述输入输出电气参数包括关断器的各输入端所耦接直流电源的输出电压、输出电流、发电量、以及关断器的输出电压和功率总线电流,所述内部运行数据包括关断器的温度、运行状态和报警信息。所述综合控制单元134将所述关断器的运行数据打包成第一数据包,并发送至协议处理单元135。所述协议处理单元135将第一数据包按照预定的通信协议进行封装,封装为第一通信信号,并将第一通信信号发送至调制单元132。
作为本发明的一种实现方式,所述控制模块13还包括驱动单元136,与调制单元132连接,根据接收的第一复合控制信号生成第一驱动信号,第一驱动信号控制开关管1221的导通与关断。
作为本发明的一种实现方式,关断器还包括信号解耦模块14,信号解耦模块14将来自所述功率总线的电力线载波信号与功率总线电流进行分离,提 取电力线载波信号。信号解耦模块14由RLC并联谐振电路组成,RLC并联谐振电路为一个带通滤波器,电力线载波信号的频率位于带通滤波器的通带内,RLC并联谐振电路为电力线载波信号提供稳定的阻抗,从而将电力线载波信号从功率线路中提取出来。所述控制模块13还包括解调单元137,接收信号解耦模块14提取的电力线载波信号,对电力线载波信号进行滤波和放大处理,获取更佳信噪比的电力线载波信号,并进行解调处理,得到第二通信信号,将所述第二通信信号发送至协议处理单元135。协议处理单元135对接收的第二通信信号按照协议格式解析出第二数据包,将第二数据包传递给综合控制单元134。综合控制单元134对第二数据包进行解析,获取第二数据包中的控制指令,根据关断器的控制指令调整关断器的运行模式,关断器的控制指令包括允许运行指令、快速关机指令和数据采集指令。关断器的运行模式包括安全断开模式和正常运行模式。协议处理单元135还生成数据发送状态信号至功率控制单元131,数据发送状态信号表征关断器发送数据的状态,包括空闲和忙两种状态,功率控制单元131根据数据发送状态信号和关断器的运行模式调整开关管1221的工作状态。
作为本发明的一种实现方式,关断器上电后的初始模式为安全断开模式,当综合控制单元134接收到允许运行指令时,将关断器的运行模式切换为正常运行模式。当综合控制单元134超过第一预设时间后没有接收到允许运行指令时或者接收到快速关机指令时,将关断器的运行模式切换为安全断开模式。
作为本发明的一种实现方式,当关断器处于正常运行模式时,若综合控制单元134接收到数据采集指令时,将关断器的运行数据打包成第一数据包,协议处理单元135将第一数据包封装为第一通信信号,发送至所述调制单元132,并将数据发送状态信号设置为忙状态。功率控制单元131根据功率总线电流调整功率控制信号的大小,进而调整第一复合控制信号的占空比。调制单元132对第一通信信号和功率控制信号进行调制,生成第一复合控制信号, 此时第一复合控制信号控制开关管1221工作在高频开关状态,以在功率总线上产生携带关断器的运行数据的电流纹波信号。当第一数据包发送完成后,协议处理单元135将数据发送状态信号设置为空闲状态,功率控制单元131将所述功率控制信号调整为第一预设值,此时所述第一复合控制信号控制开关管1221工作在常通状态。当关断器处于安全断开模式时,功率控制单元131将所述功率控制信号调整为第二预设值,此时第一复合控制信号控制开关管1221工作在断开状态。
作为本发明的一种实现方式,当关断器处于安全断开模式时,调制单元132输出低电平的第一复合控制信号,控制开关管1221处于断开状态,关断器的输出电压和功率处于受控安全状态,当关断器处于正常运行模式并且数据发送状态信号为空闲状态时,调制单元132输出高电平的第一复合控制信号,控制开关管1221处于常通状态。当关断器处于正常运行模式并且数据发送状态信号为忙状态时,调制单元132输出调制后的第一复合控制信号,第一复合控制信号控制开关管1221处于高频开关状态。功率控制信号根据功率总线电流来调整第一复合控制信号的占空比,控制光伏组件工作点的波动范围,使关断器的输入端的输入电压的纹波峰值在预设的纹波阈值内,降低关断器的输入电压纹波导致的光伏组件的输出功率在开关管1221的高频开关状态下的下降幅度。
当关断器处于安全断开模式时,同传统的关断器一样,开关管1221处于断开状态,输入端10接入的光伏组件和功率总线断开,光伏组件的输出处于开路状态,输出功率接近于零,关断器的输出电压及功率处于受限状态。当关断器处于正常运行模式时,并且开关管1221处于常通状态时,关断器的输出电压等于输入电压,关断器的输出功率等于光伏组件的输出功率,光伏组件的输出功率由功率总线电流来调节,功率总线电流受接入功率总线的光伏逆变器控制。当关断器处于正常运行模式时,并且开关管1221处于高频开关状态时,将关断器的运行数据耦合至功率总线,光伏组件的输出功率由功率 总线电流和第一复合控制信号的占空比控制。
作为本发明的一种实现方式,所述关断器还包括泄放模块15,当关断器从正常运行模式切换为安全断开模式时,综合控制单元134控制打开泄放模块15,提供泄放通道,将功率总线电压在规定时间内快速泄放到安全电压以下,即在30s内将功率总线的输出电压泄放到30V以下,以满足北美电气法规NEC2017的要求,泄放通道提供的泄放电流一般在5-10mA。当关断器从安全断开模式切换为正常运行模式时,综合控制单元134控制关闭泄放模块15,断开泄放通道。
当光伏系统中的光伏逆变器处于待机状态时,功率总线电流可能极低,比如小于1mA,根据公式(2)及本发明的一具体实施例参数,当关断器的输入电压Vin为40V,功率总线电流为1mA时,占空比D取0.5时,输出电压Vo的跌落电压ΔVo为5mV,对输出电压Vo的波形进行傅里叶分析,可以得到其基波分量的幅值为1.9mV,功率总线中基波电流纹波的幅值为19uA,产生的电力线载波信号的强度过低,导致关断器与外部通信失败。因此,当功率总线电流低于一定值时,会导致关断器的发射信号,即耦合到功率总线上的电流纹波信号强度过低,进而导致主控器无法接收到关断器发送的运行数据。在此情况下,本发明提供一种实现方式,当关断器发送第一数据包时,若功率总线电流小于一电流阈值时,打开泄放模块15,增加关断模块的输出单元的泄放电流,以增强所述电流纹波信号的强度。比如,可以通过打开泄放模块15,给关断器额外提供5-10mA的输出电流,当占空比D还是取0.5时,功率总线中的基波电流纹波会增加5至10倍,达到114uA-209uA,电力线载波信号强度大幅提高,提升通信的成功率。当第一数据包发送完成时,控制关闭泄放模块15。
作为本发明的一种实现方式,关断器还包括续流管,其并联在输出单元123的两端,和开关管1221组成开关单元122,当光伏组件遮挡、控制模块或者光伏组件故障时,给功率总线电流提供旁路通道。续流管可通过二极管 实现。
由于关断器是从输入端10对应的光伏组件取辅电以向控制模块13供电,在关断器处于正常运行模式时,当光伏组件的最大输出电流小于功率总线电流时,比如光伏组件受阴影和灰尘遮挡,以及衰减较大等工况,光伏组件的输出电压会被逐渐拉低至零,从而导致辅助电源供电中断,控制模块13掉电。为了避免控制模块13掉电,通常会断开开关管1221,功率总线电流从开关模块122的续流管流过,在此工况下,即关断器输入端的输入状态异常时,关断器的运行数据无法通过开关管1221的高频开关动作耦合至功率总线,为了实现关断器的数据发送功能,本发明在第一实施例的基础上进行改进,提出了第二实施例的关断器。与本发明第一实施例的关断器相比,关断模块12的续流管采用开关管实现,其类型例如为IGBT、MOSFET等,在光伏组件受阴影遮挡、灰尘遮挡、衰减较大等工况导致光伏组件的最大输出电流小于功率总线电流时,利用续流管的高频开关动作将关断器的运行数据等通信数据耦合至功率总线,实现关断器的通信发送功能。
图4示出本发明第二实施例的关断器的系统框图。续流管1222为开关管,为所述功率总线电流提供旁路通道。当所述关断器的输入端的输入状态异常时,所述控制模块13将一续流控制信号与所述第一通信信号进行调制,生成第二复合控制信号,所述第二复合控制信号控制所述续流管1222工作在高频开关状态,以在功率总线上叠加包含所述第一通信信号的电流纹波信号,其中,所述续流控制信号用于控制所述续流管1222的开通与关断。
作为本发明的一种实现方式,监测单元133监测关断器的输入电压Vin,输出一输入状态检测信号至功率控制单元131。功率控制单元131根据所述输入状态检测信号、关断器的运行模式以及数据发送状态信号,生成续流控制信号。功率控制单元131还根据所述输入状态检测信号、关断器的运行模式、数据发送状态信号以及功率总线电流生成功率控制信号。功率控制信号的大小和功率总线电流相关,续流控制信号为一设定值。调制单元132对功 率控制信号和第一通信信号进行调制,以及对续流控制信号和第一通信信号进行调制,生成对应的第一复合控制信号和第二复合控制信号,其中,第一复合控制信号的占空比由功率总线电流确定,第二复合控制信号的占空比为一预设值。驱动单元136分别对第一复合控制信号和第二复合控制信号进行驱动处理,得到第一驱动信号和第二驱动信号,第一驱动信号控制开关管1221,第二驱动信号控制续流管1222。
作为本发明的一种实现方式,当监测单元133检测到关断器的输入电压Vin小于一电压阈值时,判定关断器的输入端10的输入状态为异常,否则为正常。当关断器输入端10的输入状态为异常时,功率控制单元131输出功率控制信号控制开关管1221处于断开状态,输出续流控制信号控制续流管1222处于常通状态或高频开关状态,经过第二预设时间后功率控制单元131输出的功率控制信号控制开关管1221闭合,输出的续流控制信号控制续流管1222断开。比如第二预设时间设置为5mins。当关断器的输入电压Vin大于阈值电压的时长超过第三预设时间时,关断器输入端10的输入状态切换为正常状态,否则保持为异常状态。比如第三预设时间设置为100ms。
作为本发明的一种实现方式,关断器上电后的初始运行模式为安全断开模式,当综合控制单元134接收到允许运行指令,将关断器的运行模式切换为正常运行模式。当综合控制单元134超过第一预设时间后没有接收到所述允许运行指令,或者接收到快速关机指令时,将关断器的运行模式切换为安全断开模式。当关断器处于正常运行模式时,若综合控制单元134接收到数据采集指令,将关断器的运行数据打包成第一数据包并发送至协议处理单元135。协议处理单元135将第一数据包封装为第一通信信号,发送至调制单元132,并将数据发送状态信号设置为忙状态。此时若关断器输入端10的输入状态为正常状态时,功率控制单元131根据功率总线电流调整功率控制信号的大小。调制单元132将第一通信信号和功率控制信号调制成第一复合控制信号,第一复合控制信号控制开关管1221工作在高频开关状态,第二复合控 制信号控制续流管1222为断开状态。当第一数据包发送完成后,协议处理单元135将数据发送状态信号置为空闲状态,功率控制单元131将功率控制信号调整为第一预设值,此时第一复合控制信号控制开关管1221工作在常通状态,第二复合控制信号控制续流管1222保持为断开状态;若关断器输入端10的输入状态为异常状态时,调制单元132将第一通信信号和续流控制信号调制生成第二复合控制信号,第二复合控制信号控制续流管1222工作在高频开关状态,第一复合控制信号控制开关管1221处于断开状态;当第一数据包发送完成后,第二复合控制信号控制续流管1222的状态切换为常通状态。当关断器的运行模式为安全断开模式时,第一复合控制信号控制开关管1221为断开状态,第二复合控制信号控制续流管1222为断开状态。
关断器输入端10的输入状态为异常状态时,第二复合控制信号控制续流管1222工作在高频开关状态,在关断器的输出端11上产生相应的基波电压纹波,在该基波电压纹波的激励下,功率总线上会产生相应的基波电流纹波,从而将包含运行数据的第一通信信号耦合至功率总线,在功率总线上产生携带运行数据的电流纹波信号,实现关断器向外部发送数据的目的。其原理同本发明的第一实施例,这里不再重复,关断器输入端10的输入状态为正常状态时,利用开关管1221进行数据的发送,原理同第一实施例,不再赘述。
当关断器处于安全断开模式,开关管1221和续流管1222处于断开状态,输入端10接入的光伏组件和功率总线断开,光伏组件的输出处于开路状态,输出功率接近于零,关断器的输出电压及功率处于受限状态。当关断器处于正常运行模式,且关断器输入端10的输入状态为正常状态时,开关管1221处于常通状态或高频开关状态,续流管1222处于断开状态,输入端10接入的光伏组件和功率总线连通,光伏组件的输出功率受功率总线电流和第一复合控制信号的占空比控制。当关断器处于正常运行模式,且关断器输入端10的输入状态为异常状态时,开关管1221处于断开状态,输入端10接入的光伏组件和功率总线断开,续流管1222处于导通状态,功率总线电流从续流管 1222通过,当关断器发送数据时,续流管1222处于高频开关状态,将关断器需要发送的运行数据耦合至功率总线。
作为本发明的一种实现方式,开关管1221可以位于输入端10的高电位端和输出端11的高电位端之间,也可以位于输入端10的低电位端和输出端11的低电位端之间,本实施方式以位于低电位端之间为例说明。
图5示出了本发明第二实施例中关断器的调制单元132的示意框图,调制单元132包括选择开关S、第一比较器U1和第二比较器U2,第一比较器U1的第一输入端接收功率控制信号,第二输入端与选择开关S的第一端连接,第一比较器U1的输出端输出第一复合控制信号。第二比较器U2的第一输入端接收续流控制信号,第二输入端与选择开关S的第一端连接,第二比较器U2的输出端输出第二复合控制信号。选择开关S的第一端接收马克频率Fm的载波信号,第二端接收空间频率Fs的载波信号。第一通信信号控制选择开关S1选择不同频率的载波信号,当第一通信信号的bit为“1”时,选择马克频率Fm的载波信号,当第一通信信号的bit为“0”时,选择空间频率Fs的载波信号。功率控制信号和载波信号进行比较,得到第一复合控制信号;续流控制信号和载波信号进行比较,得到第二复合控制信号。当关断器输入端10的输入状态为正常状态时,第一复合控制信号可以控制开关管1221工作在高频开关状态,第二复合控制信号控制续流管1222为断开状态,第一复合控制信号的占空比决定了输入、输出电压的电压纹波,从而间接控制了光伏组件的输出功率。当关断器输入端10的输入状态为异常状态时,第一复合控制信号控制开关管1221为断开状态,第二复合控制信号控制续流管1222为常通状态或高频开关状态,当续流管工作在高频开关状态时,第二复合控制信号的占空比设定为50%。
综上,当关断器输入端的光伏组件输出异常导致其最大输出电流小于功率总线电流,在关断模块的开关管关断的情况下,本实施例通过关断器的续流管的调制控制,控制续流管工作在高频开关状态下,实现了关断器在异常 工况的数据发送,提升了关断器的环境适用性。
本发明提供一种关断器的通信方法,可以应用于上述关断器,但本发明不以此为限,本发明实施例的通信方法可应用于其他任何可以应用本发明的关断器中。关断器的通信方法包括:
将一功率控制信号与第一通信信号进行调制,生成第一复合控制信号,功率控制信号用于调节关断器的输入端10耦接的直流电源的输出功率;
第一复合控制信号控制关断器的开关管1221工作在高频开关状态下,以在功率总线上叠加包含第一通信信号的电流纹波信号。
采集并获取关断器的运行数据,将关断器的运行数据打包成第一数据包,并按照预定的通信协议将第一数据包封装为第一通信信号。关断器根据功率总线电流生成功率控制信号,对第一通信信号和功率控制信号进行调制,生成第一复合控制信号。第一复合控制信号控制开关管1221进行高频的开关动作。开关管1221在第一复合控制信号的控制下执行高频开关动作,使在关断器的输出端上产生相应的基波电压纹波,在该基波电压纹波的激励下,功率总线上产生相应的基波电流纹波,即在功率总线上产生携带运行数据的电流纹波信号,实现关断器通信数据的发送功能。
作为本发明的一种实现方式,根据关断器的功率总线电流调节功率控制信号的大小,进而控制第一复合控制信号的占空比,使关断器的输入端的输入电压的纹波峰值在一预设的纹波阈值内。
作为本发明的一种实现方式,第一复合控制信号的占空比和功率总线电流正相关,功率总线电流越大,占空比越大,反之占空比越小。
作为本发明的一种实现方式,该通信方法还包括:
提供一续流控制信号,续流控制信号用于控制关断器的续流管的开通与关断;
当关断器的输入端10的输入状态异常时,第一复合控制信号控制开关管1221断开,将一续流控制信号与第一通信信号进行调制,生成第二复合控制信号,第二复合控制信号控制续流管1222工作在高频开关状态,以在功率总线上叠加包含第一通信信号的电流纹波信号。
当关断器处于正常运行模式时,若监测到关断器的输入电压小于电压阈值时,判定关断器的输入端的输入状态为异常。当需要发送第一数据包时,将第一通信信号和续流控制信号调制生成第二复合控制信号,第二复合控制信号控制续流管1222工作在高频开关状态,第一复合控制信号控制开关管1221处于断开状态,在关断器的输出端11上产生相应的基波电压纹波,功率总线上会产生相应的基波电流纹波,从而将包含关断器运行数据的第一通信信号耦合至功率总线,实现关断器在输入端异常情况下,向外部发送数据的目的。当第一数据包发送完成后,第二复合控制信号控制续流管1222的状态切换为常通状态。
图6示出本发明第三实施例的关断器的系统框图,关断器包括:
第一输入端20,用于耦接第一直流电源;
至少一个第二输入端30,用于耦接第二直流电源;
输出端11,用于耦接功率总线;
第一关断模块22,与第一输入端20连接,第一关断模块22包括第一开关管2221,第一开关管2221用于控制第一输入端20耦接的第一直流电源的输出功率;
至少一个第二关断模块32,与第二输入端30连接,第二关断模块32包括第二开关管3221,第二开关管3221用于控制第二输入端30耦接的第二直流电源的输出功率;
第一关断模块22和第二关断模块32串联连接并与输出端11连接;
控制模块13,用于将一功率控制信号与第一通信信号进行调制,生成第一复合控制信号,其中,功率控制信号调节第一输入端20耦接的第一直流电源的输出功率,第一复合控制信号控制第一开关管2221工作在高频开关状态下,以在功率总线上叠加包含第一通信信号的电流纹波信号;
控制模块13,还用于生成开关控制信号,用以控制第二开关管3221的工作状态。
第一关断模块22还包括与第一输入端20耦接的第一输入单元221以及与输出端11耦接的第一输出单元223,第一输入单元221包括第一输入电容Cin1,用于稳定关断器第一输入端20的输入电Vin1压。第一关断模块22还包括续流管,其并联在第一输出单元223的两端,和第一开关管2221组成第一开关单元222。第一输出单元223包括第一输出电容Co1,用于稳定关断器的输出电压。第二关断模块32还包括与第二输入端30耦接的第二输入单元321以及与输出端11耦接的第二输出单元323,第二输入单元321包括第二输入电容Cin2,用于稳定关断器第二输入端30的输入电压Vin2。第二关断模块32还包括续流管,其并联在第二输出单元323的两端,和第二开关管3221组成第二开关单元322。第二输出单元323包括第二输出电容Co2,用于稳定关断器的输出电压。第二关断模块32串联在第一关断模块22的高电位输出端或低电位输出端。本申请以第二关断模块32串联在第一关断模块22的高电位输出端为例进行说明。第一关断模块22与第一实施例中关断器的关断模块的工作方式相同,相同之处不再赘述,这里仅介绍不同之处。
作为本发明的一种实现方式,控制模块13还包括开关控制单元138,用于根据关断器的运行模式,生成控制第二开关管3221的工作状态的开关控制信号,第二开关管3221的工作状态包括断开状态和常通状态。关断器的模式包括安全断开模式和正常运行模式。
关断器上电后的初始运行模式为安全断开模式,当综合控制单元134接 收到允许运行指令,将关断器的运行模式切换为正常运行模式。当综合控制单元134超过第一预设时间后没有接收到所述允许运行指令,或者接收到快速关机指令时,将关断器的运行模式切换为安全断开模式。
作为本发明的一种实现方式,当关断器处于正常运行模式时,若综合控制单元134接收到数据采集指令时,将关断器的运行数据打包成第一数据包并发送至协议处理单元135,协议处理单元135将第一数据包封装为第一通信信号,并将数据发送状态信号设置为忙状态。功率控制单元131根据功率总线电流调整将功率控制信号的大小。调制单元132对第一通信信号和功率控制信号进行调制,生成第一复合控制信号,此时第一复合控制信号控制第一开关管2221工作在高频开关状态,开关控制信号控制第二开关管3221为常通状态。当第一数据包发送完成后,协议处理单元135将数据发送状态信号设置为空闲状态,功率控制单元131将功率控制信号调整为第一预设值,此时第一复合控制信号控制第一开关管2221工作在常通状态,开关控制信号控制第二开关管3221保持为常通状态。当关断器处于安全断开模式时,功率控制单元131将功率控制信号调整为第二预设值,此时第一复合控制信号控制第一开关管2221工作在断开状态,开关控制信号控制第二开关管3221的工作状态为断开状态。
当关断器处于安全断开模式,第一开关管2221和第二开关管3221均处于断开状态,第一输入端20接入的光伏组件和功率总线的连接断开,以及第二输入端30接入的光伏组件和功率总线的连接断开,光伏组件的输出均处于开路状态,输出功率接近于零,关断器的输出电压及功率处于受限状态。当关断器处于正常运行模式,第一开关管2221处于常通状态或高频开关状态,第二开关管3221处于常通状态,第一输入端20接入的光伏组件和功率总线连通,以及第二输入端30接入的光伏组件和功率总线连通,第一输入端20接入的光伏组件的输出功率受功率总线电流和第一复合控制信号的占空比两者的控制,第二输入端30接入的光伏组件的输出功率受功率总线电流控制。
作为本发明的一种实现方式,第一开关管2221可以位于第一输入端20的高电位端和输出端11的高电位端之间,也可以位于第一输入端20的低电位端和输出端11的低电位端之间,第二开关管3221可以位于第二输入端30的高电位端和输出端11的高电位端之间,也可以位于第二输入端30的低电位端和输出端11的低电位端之间,本实施方式均以位于高电位端之间为例说明。
本实施例的关断器包括多个输入端,为多输入的拓扑结构,可以选择任意一输入端对应的开关管工作在高频开关状态,实现将关断器的运行数据耦合至功率总线进行数据发送的目的,多个开关管共用一个控制模块,可以提高关断器的集成度和功率密度,大幅降低产品的生产成本。
如图6所示的第三实施例的关断器中,关断器连接有多个光伏组件,当关断器进行数据发送,且进行数据发送的第一关断模块22所连接的第一光伏组件正常时,功率总线电流等于第一光伏组件的输出电流,根据功率总线电流调节第一复合控制信号的占空比。但是在第一光伏组件异常时,例如在第一光伏组件受阴影遮挡、灰尘遮挡、衰减较大等工况,导致第一光伏组件的输出电流小于功率总线电流时,第一光伏组件的输出电压被短路至零,若采用和上述实施例中相同的占空比控制方案,在功率总线上产生的电力线载波信号的强度会比较弱,导致数据发送失败。下面进行详细说明。
关断器通过第一开关管2221的高频开关动作实现第一通信信号发送功能的原理说明如下。当第一光伏组件正常时,第一开关管2221工作在高频开关状态时,在第一开关管2221瞬时断开期间,第一光伏组件的输出电流I PV1向第一输入电容Cin1充电,第一输入电容Cin1两端的输入电压Vin1被抬升。第一光伏组件的输出电流I PV1等于功率总线电流I,第一关断模块22的输入电压Vin1在此期间线性上升,其过充电压ΔVin1如式(3)所示:
ΔVin1=(I·(1-D)·T)/C in1  (3);
其中,I为功率总线电流,T为第一复合控制信号的周期,D为第一复合控制信号的占空比,C in1为第一输入电容Cin1的容值。
第一关断模块22的输出电压Vo1线性下跌,跌落电压ΔVo1如式(4)所示:
ΔVo1=(I·(1-D)·T)/C o1  (4);
其中,C o1为第二输出电容Co1的容值。
当第一开关管2221闭合时,第一输入电容Cin1在第一开关管2221断开期间存储的能量通过第一开关管2221快速转移到第一输出电容Co1,补偿第一输出电容Co1在第一开关管2221关断期间泄放掉的能量,同时第一关断模块22的输入电压Vin1和输出电压Vo1恢复至稳态电压。关断器的输出电压Vo为第一关断模块22的输出电压Vo1和第二关断模块32的输出电压Vo2之和,在第一开关管2221工作在高频开关状态时,关断器的输出电压Vo包含丰富的高频开关管谐波,对输出电压Vo进行傅里叶分解,可以得到输出电压Vo的直流分量、基波分量及各次谐波分量,其中,基波分量的频率为第一开关管2221的开关频率。在输出电压Vo的基波分量的激励下,功率总线产生对应的基波电流纹波。根据以上分析可知,根据包含关断器运行数据的第一通信信号对关断器的输出电压所包含的基波分量进行调制,可以在功率总线上注入携带第一通信信号的电力线载波信号,可以实现关断器的数据发送,本实施例中,电力线载波信号为电流纹波信号的基波分量,即基波电流纹波。
因此,当第一光伏组件正常时,根据功率总线电流I计算得到第一复合控制信号的占空比D,第一开关管2221在第一复合控制信号的控制下执行高频开关动作,在关断器的输出端11上会产生相应的基波电压纹波,在该基波电压纹波的激励下,功率总线上产生相应的基波电流纹波,即在功率总线上产生携带运行数据的电流纹波信号,实现关断器通信数据的发送功能。在第 一光伏组件异常时,例如在第一光伏组件受阴影遮挡、灰尘遮挡、衰减较大等工况,导致第一光伏组件的输出电流I PV1小于功率总线电流I,即关断器的第一输入端20的输入状态异常时,续流管导通,功率总线电流I分别流经第一光伏组件和续流管,此时第一关断模块22的输入电压Vin1被拉低至0,即,若采用上述实施例的占空比方案,在功率总线上产生的电力线载波信号的强度会比较弱,导致数据发送失败。例如,如图7所示,在T=1/100kHz,第一输出电容Co1为1uF的情况下,第一光伏组件正常工作时,I PV1=I=10A,占空比D=0.98,根据公式(4)计算得到第一关断模块22的输出电压Vo1的跌落电压ΔVo1为2V,对输出电压Vo的波形进行傅里叶分解,可以得到输出电压Vo的基波分量的幅值为38mV,该输出电压Vo的基波分量在功率总线上产生幅值为0.38mA的基波电流纹波。当第一光伏组件异常时,I仍旧为10A,但第一光伏组件的输出电流I PV1降至2A,此时跌落电压为ΔVo1=0.3V,在功率总线上产生的基波电流纹波非常微弱,容易导致数据发送失败。因此在第一光伏组件异常时,在进行数据发送时,需要调整第一复合控制信号的占空比的控制策略。为了提高光伏组件异常时耦合至功率总线的电力线载波信号的强度,本发明提出了第四实施例的关断器。
图8示出本发明第四实施例的关断器的系统框图,在本实施例中,在进行数据发送时,通过第一复合控制信号控制开关管2221工作在高频开关状态下,以在功率总线上叠加电力线载波信号。与第三实施例相比,控制模块13还根据第一关断模块22的输入电压Vin1控制第一复合控制信号的占空比。
作为本发明的一种实现方式,当关断器的第一输入端20的输入状态异常,在进行数据发送时,控制模块13根据第一关断模块22的输入电压Vin1控制第一复合控制信号的占空比。
作为本发明的一种实现方式,控制模块13还包括电压控制单元139和选择单元140,电压控制单元139根据第一关断模块22的输入电压Vin1产生电压控制信号。选择单元140分别与功率控制单元131和电压控制单元139连接,根据 第一输入端20的输入状态检测信号和数据发送状态信号,选择输出功率控制信号或者电压控制信号至调制单元132。
作为本发明的一种实现方式,当输入状态检测信号表示第一输入端20的输入状态正常时,选择单元140选择输出功率控制信号,调制单元132对第一通信信号和功率控制信号进行调制生成第一复合控制信号。当输入状态检测信号表示第一输入端20的输入状态异常,在进行数据发送时,选择单元140选择输出电压控制信号,调制单元132对第一通信信号和电压控制信号进行调制生成第一复合控制信号,数据发送完成时,选择单元140选择输出功率控制信号,调制单元132对第一通信信号和功率控制信号进行调制生成第一复合控制信号。
作为本发明的一种实现方式,当关断器处于正常运行模式时,若综合控制单元134接收到数据采集指令时,将关断器的运行数据打包成第一数据包并发送至协议处理单元135,协议处理单元135将第一数据包封装为第一通信信号,并将数据发送状态信号设置为忙状态。当关断器第一输入端20的输入状态为正常状态时,功率控制单元131根据功率总线电流调整将功率控制信号的大小。选择单元140选择输出功率控制信号至调制单元132。调制单元132对第一通信信号和功率控制信号进行调制,生成第一复合控制信号,此时第一复合控制信号控制第一开关管2221工作在高频开关状态,开关控制信号控制第二开关管3221为常通状态。当第一数据包发送完成后,协议处理单元135将数据发送状态信号设置为空闲状态,功率控制单元131将功率控制信号调整为第一预设值,此时第一复合控制信号控制第一开关管2221工作在常通状态,开关控制信号控制第二开关管3221保持为常通状态。当关断器处于安全断开模式时,功率控制单元131将功率控制信号调整为第二预设值,此时第一复合控制信号控制第一开关管2221工作在断开状态,开关控制信号控制第二开关管3221的工作状态为断开状态。
作为本发明的一种实现方式,当关断器处于正常运行模式时,若综合控 制单元134接收到数据采集指令时,将关断器的运行数据打包成第一数据包并发送至协议处理单元135,协议处理单元135将第一数据包封装为第一通信信号,并将数据发送状态信号设置为忙状态。当关断器第一输入端20的输入状态为异常状态时,电压控制单元139根据第一关断模块22的输入电压Vin1调节电压控制信号的大小,选择单元140选择输出电压控制信号至调制单元132。调制单元132将第一通信信号和电压控制信号调制成第一复合控制信号,第一复合控制信号控制第一开关管2221工作在高频开关状态,开关控制信号控制第二开关管3221为常通状态。当第一数据包发送完成后,协议处理单元135将数据发送状态信号设置为空闲状态,选择单元140选择输出功率控制信号至调制单元132。功率控制单元131将功率控制信号调整为第一预设值,此时第一复合控制信号控制第一开关管2221工作在常通状态,开关控制信号控制第二开关管3221保持为常通状态。当关断器处于安全断开模式时,功率控制单元131将功率控制信号调整为第二预设值,此时第一复合控制信号控制第一开关管2221工作在断开状态,开关控制信号控制第二开关管3221的工作状态为断开状态。
作为本发明的一种实现方式,当监测单元133监测到第一关断模块22的输入电压Vin1小于一相应的预设的电压阈值时,判定关断器的第一输入端20的输入状态为异常,否则为正常,并输出表示第一输入端20的输入状态的输入状态检测信号。
作为本发明的一种实现方式,根据第一关断模块22的输入电压Vin1控制第一复合控制信号的占空比。当第一关断模块22的输入电压Vin1的峰值大于预设的第一参考电压时,增大第一复合控制信号的占空比,以使关断器的第一输入端20的输入电压的纹波峰值在一预设的纹波阈值内;当第一关断模块22的输入电压Vin1的峰值低于第一参考电压时,减小第一复合控制信号的占空比,以增大电力线载波信号的强度,满足数据发送中信号强度的要求,防止数据发送失败。
作为本发明的一种实现方式,根据第一关断模块22的输入电压Vin1控制第一复合控制信号的占空比。当第一关断模块22的输入电压Vin1的平均值大于预设的第二参考电压时,增大第一复合控制信号的占空比,以使关断器的第一输入端20的输入电压的纹波峰值在一预设的纹波阈值内;当第一关断模块22的输入电压Vin1的平均值小于第二参考电压时,减小所述第一复合控制信号的占空比,以增大电力线载波信号的强度,满足数据发送中信号强度的要求,防止数据发送失败。
作为本发明的一种实现方式,电压控制单元139包括误差放大器和控制器,误差放大器用于获取所述第一关断模块22的输入电压Vin1和参考电压之间的误差放大值。控制器根据误差放大值产生电压控制信号。控制器例如为PI控制器或Bang-Bang控制器等。参考电压为第一参考电压,或者为第二参考电压。误差放大器计算输入电压Vin的峰值ΔV in1_peak和第一参考电压之间的误差放大值或输入电压Vin的平均值V in1_ave和第二参考电压之间的误差放大值。
作为本发明的一种实现方式,在第二关断模块32和第一关断模块22的输出端之间串联采样电阻Rcs,根据采样电阻Rcs两端的电压获得功率总线电流I,在本实施例中,为了控制简单,第一关断模块22和采样电阻Rcs之间的连接点作为公共地。
以下将结合附图9介绍本发明实施例的工作原理。图9是根据本发明的一个实施例的关断器的第一关断模块进行数据发送时的输入输出电压波形图,如图9所示,第一光伏组件异常时,在第一开关管2221断开期间,第一光伏组件的输出电流I PV1向第一输入电容Cin1充电,第一输入电容Cin1两端的输入电压Vin1被抬升,关断器的输入电压Vin1在此期间线性上升,过充电压ΔVin1如式(3)所示。当第一开关管2221闭合时,假设在闭合过程,第一输入电容Cin1上的能量无损的转移一部分到第一输出电容Co1,则第一输出电容Co1上的跌落电压ΔVo1为:
ΔVo1=sqrt(C in1/(C o1+C in1))*ΔVin1  (5);
由以上分析可知,电流纹波信号的强度和第一光伏组件的输出电流I PV1相关,即与第一关断模块22的输入电流I PV1相关,可以根据第一关断模块22的输入电流调节第一复合控制信号的占空比的大小,即根据第一关断模块22的输入电流来计算占空比。
在实际应用中,第一关断模块22的输入电流不容易检测,根据光伏组件的电压电流特性,因此可以通过检测第一关断模块22的输入电压Vin1,根据输入电压Vin1来调节第一复合控制信号的占空比。
第一关断模块22的输入电压的峰值ΔV in1_peak为:
Figure PCTCN2022126260-appb-000001
第一输出电容Co1上的跌落电压ΔVo1的峰值ΔV o1_peak为:
Figure PCTCN2022126260-appb-000002
其中,ΔT为输出电压Vo1下降的时间;
因此可知,提高电流纹波信号的强度需要增大跌落电压ΔVo1的峰值ΔV o1_peak,ΔV o1_peak和ΔV in1_peak成正比例,而ΔV in1_peak又和占空比相关,因此可以根据输入电压Vin1的峰值ΔV in1_peak的大小调节第一复合控制信号占空比的大小。具体的,当输入电压Vin1的峰值ΔV in1_peak大于第一参考电压时,增大占空比;当输入电压Vin1的峰值ΔV in1_peak低于第一参考电压时,减小占空比,以增大跌落电压ΔVo1的峰值,增大电流纹波信号的强度,满足数据发送中载波信号强度的要求,防止数据发送失败。
作为本发明的一种实现方式,由以上公式可知,第一关断模块22的输入电压Vin1的均值V in1_ave为:
Figure PCTCN2022126260-appb-000003
进一步得到:
Figure PCTCN2022126260-appb-000004
Figure PCTCN2022126260-appb-000005
Figure PCTCN2022126260-appb-000006
由以上输入电压V in1的峰值ΔV in1_peak和输入电压V in1的平均值V in1_ave之间的关系式可知,可以根据输入电压V in1的平均值V in1_ave调节第一复合控制信号占空比的大小。具体的,当输入电压V in1的平均值V in1_ave大于第二参考电压时,增大占空比,当输入电压V in1的平均值V in1_ave低于第二参考电压时,减小占空比,增大电力线载波信号的强度,满足数据发送中载波信号强度的要求,防止数据发送失败。
作为本发明的一种实现方式,与第二关断模块32连接的第二光伏组件为控制模块13提供电源。
在其他实施例中,关断器中关断模块的个数可以为3、4、5等任意个数,相应的关断器的输入端可以连接3、4、5等个光伏组件,用于为控制模块供电的光伏组件所对应的关断模块的输出和用于发送数据的关断模块的输出串联连接。
作为本发明的一种实现方式,如图10所示的第五实施例的关断器,第一关断模块22包括续流管2222,续流管2222为开关管,当关断器的第一输入端20的输入状态异常时,在进行数据发送时,第一复合控制信号控制第一开关管2221工作在高频开关状态,控制续流管2222为断开状态;当关断器的第一输入端20的输入状态异常时,在不进行数据发送时,控制第一开关管2221和续流管2222均为闭合状态,为功率总线电流提供续流通道。
本发明提供一种关断器的通信方法,可以应用于上述关断器。关断器的 通信方法包括:
将一功率控制信号与第一通信信号进行调制,生成第一复合控制信号,功率控制信号用于调节关断器的第一输入端20所耦接的第一直流电源的输出功率;
第一复合控制信号控制关断器的第一输入端20的第一开关管2221工作在高频开关状态下,以在功率总线上叠加包含述第一通信信号的电流纹波信号;
提供一开关控制信号,开关控制信号用以控制关断器的第二输入端的第二开关管的工作状态。
作为本发明的一种实现方式,关断器的通信方法还包括:根据关断器的功率总线电流调节功率控制信号的大小,进而控制第一复合控制信号的占空比,使关断器的输入端的输入电压的纹波峰值在一预设的纹波阈值内。
作为本发明的一种实现方式,关断器的通信方法还包括:当进行数据发送时,根据功率总线电流生成功率控制信号,将功率控制信号与第一通信信号调制生成第一复合控制信号,第一复合控制信号控制关断器的第一开关管2221工作在高频开关状态,开关控制信号控制关断器的第二开关管3221为常通状态;当数据发送完成后,第一复合控制信号控制第一开关管2221工作在常通状态,开关控制信号控制述第二开关管3221保持为常通状态。
作为本发明的一种实现方式,当关断器第一输入端20的输入状态异常,在进行数据发送时,根据关断器的第一关断模块22的输入电压控制第一复合控制信号的占空比。
具体的,根据第一关断模块22的输入电压产生电压控制信号,对第一通信信号和电压控制信号进行调制生成第一复合控制信号。当关断器的第一输入端20的输入状态正常时,对第一通信信号和功率控制信号进行调制,生成第一复合控制信号;当关断器的第一输入端20的输入状态异常,在进行数据 发送时,对第一通信信号和电压控制信号进行调制生成第一复合控制信号,第一复合控制信号控制关断器的第一开关管2221工作在高频开关状态,所述开关控制信号控制所述关断器的第二开关管3221为常通状态,数据发送完成时,对第一通信信号和功率控制信号进行调制,生成第一复合控制信号,第一复合控制信号控制第一开关管2221工作在常通状态,开关控制信号控制第二开关管3221保持为常通状态。
作为本发明的一种实现方式,关断器的通信方法还包括:当第一关断模块22的输入电压的峰值大于等于预设的第一参考电压时,增大第一复合控制信号的占空比,当第一关断模块22的输入电压的峰值小于第一参考电压时,减小第一复合控制信号的占空比。
作为本发明的一种实现方式,关断器的通信方法还包括:当第一关断模块22的输入电压的均值大于等于预设的第二参考电压时,增大第一复合控制信号的占空比,当第一关断模块22的输入电压的均值小于第二参考电压时,减小第一复合控制信号的占空比。
如图11所示的本发明一个实施例中,本发明提供一种快速关断光伏系统,系统包括多个光伏组件40、多个关断器41、主控器42、光伏逆变器43及并网开关44,每一个关断器41接入第一光伏组件和第二光伏组件,多个关断器41串接在一功率总线上,功率总线接入光伏逆变器43的直流输入端口,关断器41包括第一输入端和至少一个第二输入端、与第一输入端连接的第一关断模块、与第二输入端连接的第二关断模块、输出端以及控制模块,第一关断模块包括第一开关管,第二关断模块包括第二开关管,
关断器41,用于将功率控制信号与第一通信信号进行调制,并调制生成第一复合控制信号,所述功率控制信号调节第一输入端耦接的第一直流电源的输出功率,所述第一复合控制信号控制所述第一开关管工作在高频开关状态下,以在功率总线上叠加包含所述第一通信信号的电流纹波信号,所述关 断器还用于根据关断器的运行模式生成开关控制信号,用以控制第二开关管的工作状态;
主控器42,用于提取功率总线中的电流纹波信号,进行解调和解析处理,获取关断器发送的第一通信信号。
主控器42包括电力线载波收发器和电流互感器,通过电流互感器提取关断器41耦合到功率总线上的电力线载波信号(即所述电流纹波信号),并经过电力线载波收发器的解调、解析处理,得到关断器41发送的第一数据包,第一数据包包括关断器41的运行数据。主控器42发送的包括关断器的控制指令的第二数据包经过电力线载波收发器的协议封装及调制处理后,再通过电流互感器耦合到功率总线上,并通过功率总线传输至每一个关断器41。
主控器42采用主从轮询的方式和各个关断器41进行点对点通讯,主控器42定期发送控制指令采集关断器41的运行数据,并控制关断器的运行模式。主控器42的控制指令中包含一允许运行指令,用于控制光伏系统的运行状态。当允许运行指令正常发送时,若各个关断器41正常接收到允许运行指令,各个关断器41处于正常运行模式,关断器的开关管处于常通状态或高频开关状态,输入的光伏组件正常串联接入功率总线,光伏系统处于正常运行状态;当允许运行指令停止发送超过一定时间后,各个关断器41切换为安全断开模式,其开关管处于断开状态,关断器41的输入端的光伏组件40和功率总线之间的连接断开,功率总线电压在规定时间内快速泄放到安全电压内,光伏系统处于安全断开模式。
关断器41通过内部的RLC解耦电路提取主控器42发送到功率总线上的电力线载波信号,经过调理、解调及解析处理得到主控器发送的轮询指令,若该轮询指令的采集地址与关断器41的地址匹配,则该关断器将采集的运行数据,经过内部的协议处理单元、功率控制单元、调制单元综合处理生成第一复合控制信号,关断器41的开关管接收第一复合控制信号,使开关管工作 在高频开关状态,并在功率总线上注入携带关断器41的运行数据的电力线载波信号,并通过功率总线耦接到主控器42,主控器42获取关断器41的运行数据。
尽管为示例目的,已经公开了本发明的优选实施方式,但是本领域的普通技术人员将意识到,在不脱离由所附的权利要求书公开的本发明的范围和精神的情况下,各种改进、增加以及取代是可能的。

Claims (24)

  1. 一种关断器,其特征在于,所述关断器包括:
    第一输入端,用于耦接第一直流电源;
    至少一个第二输入端,用于耦接第二直流电源;
    输出端,用于耦接功率总线;
    第一关断模块,与第一输入端连接,第一关断模块包括第一开关管,第一开关管用于控制第一输入端耦接的第一直流电源的输出功率;
    至少一个第二关断模块,与第二输入端连接,第二关断模块包括第二开关管,第二开关管用于控制第二输入端耦接的第二直流电源的输出功率;
    所述第一关断模块和至少一个第二关断模块的输出串联连接,并与所述输出端连接;
    控制模块,用于将一功率控制信号与第一通信信号进行调制,生成第一复合控制信号,其中,所述功率控制信号调节第一输入端耦接的第一直流电源的输出功率,所述第一复合控制信号控制所述第一开关管工作在高频开关状态下,以在功率总线上叠加包含所述第一通信信号的电流纹波信号;
    控制模块,还用于生成开关控制信号,用以控制第二开关管的工作状态。
  2. 如权利要求1所述的关断器,其特征在于,所述控制模块根据功率总线电流调节所述功率控制信号的大小,进而控制所述第一复合控制信号的占空比,使关断器的输入端的输入电压的纹波峰值在一预设的纹波阈值内。
  3. 如权利要求2所述的关断器,其特征在于,所述第一复合控制信号的占空比和所述功率总线电流正相关,所述功率总线电流越大,所述占空比越大,反之所述占空比越小。
  4. 如权利要求2所述的关断器,其特征在于,所述控制模块包括:
    功率控制单元,用于根据所述功率总线电流生成功率控制信号;
    调制单元,用于接收所述第一通信信号和所述功率控制信号,并对所述第一通信信号和所述功率控制信号进行调制生成所述第一复合控制信号;
    开关控制单元,所述开关控制单元用于生成控制所述第二开关管的工作状态的开关控制信号。
  5. 如权利要求4所述的关断器,其特征在于,所述控制模块还包括:
    监测单元,用于采集并获取关断器的运行数据;
    综合控制单元,用于将所述关断器的运行数据打包成第一数据包;
    协议处理单元,用于将所述第一数据包按照预定的通信协议封装为所述第一通信信号,并发送至所述调制单元。
  6. 如权利要求5所述的关断器,其特征在于,
    当进行数据发送时,所述综合控制单元将关断器的运行数据打包成第一数据包并发送至协议处理单元,所述第一复合控制信号控制所述第一开关管工作在高频开关状态,所述开关控制信号控制所述第二开关管为常通状态;
    当数据发送完成后,所述第一复合控制信号控制第一开关管工作在常通状态,所述开关控制信号控制所述第二开关管保持为常通状态。
  7. 如权利要求5所述的关断器,其特征在于,所述关断器还包括信号解耦模块,将来自所述功率总线的电力线载波信号与功率总线电流进行分离,提取电力线载波信号;
    所述控制模块还包括解调单元,用于将所述提取的电力线载波信号解调后得到第二通信信号;
    所述协议处理单元,还用于对所述第二通信信号按照协议格式解析出第二数据包,将第二数据包传递给综合控制单元,综合控制单元对第二数据包进行解析,获取第二数据包中的控制指令,所述控制指令用于控制关断器的工作状态。
  8. 如权利要求5所述的关断器,其特征在于,当所述关断器第一输入端的输入状态异常,在进行数据发送时,所述控制模块根据所述第一关断模块的输入电压控制所述第一复合控制信号的占空比。
  9. 如权利要求8所述的关断器,其特征在于,当所述第一关断模块的输入电压的峰值大于等于预设的第一参考电压时,增大所述第一复合控制信号的占空比,当所述第一关断模块的输入电压的峰值小于所述第一参考电压时,减小所述第一复合控制信号的占空比。
  10. 如权利要求8所述的关断器,其特征在于,当所述第一关断模块的输入电压的均值大于等于预设的第二参考电压时,增大所述第一复合控制信号的占空比,当所述第一关断模块的输入电压的均值小于所述第二参考电压时,减小所述第一复合控制信号的占空比。
  11. 如权利要求8所述的关断器,其特征在于,当所述监测单元监测到所述关断器的第一关断模块的输入电压小于预设的电压阈值时,判定所述第一输入端的输入状态为异常,否则为正常,并输出用以表示所述第一输入端的输入状态的输入状态检测信号。
  12. 如权利要求11所述的关断器,其特征在于,所述控制模块还包括:
    电压控制单元,用于根据所述第一关断模块的输入电压产生电压控制信号;
    选择单元,分别与所述功率控制单元和所述电压控制单元连接,用于根据所述输入状态检测信号,选择输出所述功率控制信号或者电压控制信号,以控制所述第一复合控制信号的占空比。
  13. 如权利要求12所述的关断器,其特征在于,当第一输入端的输入状态正常时,所述选择单元选择输出所述功率控制信号,所述调制单元对所述第一通信信号和所述功率控制信号进行调制,生成所述第一复合控制信号;
    当第一输入端的输入状态异常,在进行数据发送时所述选择单元选择输出所述电压控制信号,所述调制单元对所述第一通信信号和所述电压控制信号进行调制,生成所述第一复合控制信号,在数据发送完成时,所述选择单元选择输出所述功率控制信号。
  14. 如权利要求12所述的关断器,其特征在于,所述电压控制单元包括:
    误差放大器,用于获取所述第一关断模块的输入电压和参考电压之间的误差放大值;
    控制器,用于根据所述误差放大值产生所述电压控制信号。
  15. 如权利要求1所述的关断器,其特征在于,与所述第一关断模块相邻的第二关断模块所连接的第二直流电源用于向所述控制模块提供电源。
  16. 如权利要求1所述的关断器,其特征在于,所述关断器还包括采样电阻, 所述采样电阻分别与所述第一关断模块以及与所述第一关断模块相邻的第二关断模块连接,所述采样电阻用于获取功率总线电流,所述采样电阻和所述第一关断模块之间的连接点作为公共地。
  17. 一种关断器的通信方法,其特征在于,所述方法包括:
    将一功率控制信号与第一通信信号进行调制,生成第一复合控制信号,所述功率控制信号用于调节关断器的第一输入端所耦接的第一直流电源的输出功率;
    所述第一复合控制信号控制所述关断器的第一输入端的第一开关管工作在高频开关状态下,以在功率总线上叠加包含所述第一通信信号的电流纹波信号;提供一开关控制信号,所述开关控制信号用以控制所述关断器的第二输入端的第二开关管的工作状态。
  18. 如权利要求17所述的关断器的通信方法,其特征在于,所述方法还包括:根据关断器的功率总线电流调节所述功率控制信号的大小,进而控制所述第一复合控制信号的占空比,使关断器的输入端的输入电压的纹波峰值在一预设的纹波阈值内。
  19. 如权利要求17所述的关断器的通信方法,其特征在于,所述方法还包括:当进行数据发送时,根据功率总线电流生成功率控制信号,将所述功率控制信号与所述第一通信信号调制生成所述第一复合控制信号,所述第一复合控制信号控制所述关断器的第一开关管工作在高频开关状态,所述开关控制信号控制所述关断器的第二开关管为常通状态;
    当数据发送完成后,所述第一复合控制信号控制所述第一开关管工作在常通状态,所述开关控制信号控制所述第二开关管保持为常通状态。
  20. 如权利要17所述的关断器的通信方法,其特征在于,所述方法还包括:当所述关断器第一输入端的输入状态异常,在进行数据发送时,根据关断器的第一关断模块的输入电压控制所述第一复合控制信号的占空比。
  21. 如权利要20所述的关断器的通信方法,其特征在于,当所述第一关断模块的输入电压的峰值大于等于预设的第一参考电压时,增大所述第一复合控 制信号的占空比,当所述第一关断模块的输入电压的峰值小于所述第一参考电压时,减小所述第一复合控制信号的占空比。
  22. 如权利要20所述的关断器的通信方法,其特征在于,当所述第一关断模块的输入电压的均值大于等于预设的第二参考电压时,增大所述第一复合控制信号的占空比,当所述第一关断模块的输入电压的均值小于所述第二参考电压时,减小所述第一复合控制信号的占空比。
  23. 如权利要求20所述的关断器的通信方法,其特征在于,所述方法还包括:当所述关断器的第一输入端的输入状态正常时,对所述第一通信信号和所述功率控制信号进行调制,生成所述第一复合控制信号;
    当所述关断器的第一输入端的输入状态异常,在进行数据发送时,根据第一关断模块的输入电压产生电压控制信号,对所述第一通信信号和所述电压控制信号进行调制生成所述第一复合控制信号,数据发送完成时,对所述第一通信信号和所述功率控制信号进行调制,生成所述第一复合控制信号。
  24. 一种快速关断光伏系统,其特征在于,所述系统包括多个关断器、多个光伏组件、主控器以及光伏逆变器,每一个关断器接入第一光伏组件和第二光伏组件,多个关断器串接在一功率总线上,所述功率总线接入光伏逆变器的直流输入端口,所述关断器包括第一输入端、至少一个第二输入端、与第一输入端连接的第一关断模块、与第二输入端连接的第二关断模块、输出端以及控制模块,所述第一关断模块包括第一开关管,所述第二关断模块包括第二开关管,其中,
    所述关断器,用于将功率控制信号与第一通信信号进行调制,并调制生成第一复合控制信号,所述功率控制信号调节第一输入端耦接的第一直流电源的输出功率,所述第一复合控制信号控制所述第一开关管工作在高频开关状态下,以在功率总线上叠加包含所述第一通信信号的电流纹波信号,所述关断器还用于生成开关控制信号,用以控制所述第二开关管的工作状态;
    所述主控器,用于提取功率总线中的电流纹波信号,进行解调和解析处理,获取关断器发送的第一通信信号。
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