CN111463832B - Control method for realizing off-grid synchronous switching function of multiple energy storage converters - Google Patents
Control method for realizing off-grid synchronous switching function of multiple energy storage converters Download PDFInfo
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
- H02J3/40—Synchronising a generator for connection to a network or to another generator
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/24—Arrangements for preventing or reducing oscillations of power in networks
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
- H02J3/40—Synchronising a generator for connection to a network or to another generator
- H02J3/44—Synchronising a generator for connection to a network or to another generator with means for ensuring correct phase sequence
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J9/00—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting
- H02J9/04—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source
- H02J9/06—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source with automatic change-over, e.g. UPS systems
- H02J9/062—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source with automatic change-over, e.g. UPS systems for AC powered loads
Abstract
The invention relates to a control method for realizing off-grid synchronous switching function of a plurality of energy storage converters, which is technically characterized by comprising the following steps: the FPGA controller receives a power grid phase angle signal, a power grid amplitude signal and an off-grid enabling signal through a control signal input circuit; the FPGA controller generates an off-grid phase angle synchronous signal and an off-grid enabling signal through a phase angle output unit and an enabling output unit and outputs the off-grid phase angle synchronous signal and the off-grid enabling signal to a plurality of parallel energy storage converters at the same time; the energy storage converters receive the off-grid phase angle synchronous signals and then generate own off-grid phase angles, and the energy storage converters cut into an off-grid running state after receiving off-grid enabling signals. The invention has reasonable design, improves the stability of the power grid when the energy storage converter is switched into off-grid operation from grid-connected operation, can seamlessly and rapidly provide load power supply, does not cause power failure to influence the normal operation of the load, and has the characteristics of high instantaneity, reliable performance and the like.
Description
Technical Field
The invention belongs to the technical field of energy storage converters, and particularly relates to a control method for realizing off-grid synchronous switching function of a plurality of energy storage converters.
Background
At present, an energy storage converter (Power Conversion System-PCS) is widely used in power grid operation, the PCS can control the charging and discharging processes of a storage battery to perform alternating current-direct current conversion, and the power can be directly supplied to an alternating current load under the condition of no power grid. The PCS is composed of a DC/AC bidirectional converter, a control unit and the like. The PCS controller receives a background control instruction through communication, and controls the converter to charge or discharge the battery according to the sign and the size of the power instruction, so that the active power and the reactive power of the power grid are regulated.
The existing off-grid synchronous switching method and device for the energy storage converters can only realize that 1 or 2 energy storage converters and several energy storage converters can be simultaneously switched to off-grid operation, and can not realize that tens or even hundreds of energy storage converters can be simultaneously switched to off-grid operation. The stable establishment of the off-grid power grid of the large-scale MW level and the tens of MW level and the uninterrupted power supply function of the load are more difficult to realize.
Disclosure of Invention
The invention aims to overcome the defects of the prior art, and provides a control method for realizing the off-grid synchronous switching function of a plurality of energy storage converters, which can realize that all the energy storage converters enter an off-grid running state at the same time, ensure that a power grid is stable and the load is not powered off.
The invention solves the technical problems by adopting the following technical scheme:
a control method for realizing off-grid synchronous switching function of a plurality of energy storage converters comprises the following steps:
step 2, the FPGA controller generates off-grid phase angle synchronous signals and off-grid enabling signals through a phase angle output unit and an enabling output unit and outputs the off-grid phase angle synchronous signals and the off-grid enabling signals to a plurality of parallel energy storage converters at the same time;
and 3, generating an off-grid phase angle of the energy storage converters after the plurality of energy storage converters receive the off-grid phase angle synchronous signals, and switching the energy storage converters into an off-grid running state after the plurality of energy storage converters receive the off-grid enabling signals.
And step 1, acquiring a power grid phase angle signal, a power grid amplitude signal and an off-grid enabling signal through an external power grid, an upper computer and a high-voltage switch cabinet.
The phase angle output unit comprises a phase angle output unit and comprises a comparator A1, a counter A2, a comparator A3, a comparator A4, a monostable register A5, a switching logic module A6 and a comparator A7, and the generation method of the phase angle output unit comprises the following steps:
in a comparator A1, when the output value of a counter A2 is larger than a parameter K1, the counter A2 is reset, counting is started from 0, and the counter A2 is counted circularly to generate a phase angle signal with fixed power grid frequency, the counter A2 can be counted by the rising edge of an off-grid enabling signal, the power grid phase angle is arranged in the counter A2, the counter A2 starts counting from the current power grid phase angle, tracking of the power grid phase angle is realized by the output phase angle, when the output value of the counter A2 is smaller than the parameter K2, the comparator A3 outputs a high level, and then the comparator A3 outputs a synchronous phase angle signal with fixed power grid frequency to the comparator A7;
secondly, the comparator A4 and the monostable register A5 generate phase angle synchronous signals according to the actual power grid phase angle, the comparator A4 compares the power grid phase angle with the parameter K3 to judge the zero crossing position of the actual power grid phase angle, and the monostable register A5 generates high-level signals of the parameter T1 time so as to obtain the synchronous signals of the actual power grid phase angle and output the synchronous signals to the comparator A7;
thirdly, the switching logic module A6 realizes the switching of the actual power grid phase angle and the fixed power grid phase angle through the comparator A7 according to the switching logic generated by the power grid amplitude and the off-grid enabling signal;
the parameter K1 is a power grid period, the parameter K2 is a pulse width of a high level, the parameter K3 is a minimum detection value when a power grid phase angle is zero, and the parameter T1 is a high level duration of a phase angle synchronous signal.
The switching logic module A6 includes a comparator A9, a falling edge delay a10, an not gate a11, an and gate a12, a rising edge delay a13, an not gate a14, a comparator a15, an and gate a16, an or gate a17 and an RS register a18, and the switching implementation method of the switching logic module is as follows:
(1) when the energy storage converter operates in a grid-connected state, no off-grid enabling signal exists, a phase angle synchronous signal is generated by an actual power grid phase angle, a comparator A9 compares the power grid amplitude with a parameter K4, the off-grid enabling signal is 0, an RS register A18 is set to be 1, and an output switching signal is 1;
(2) when the energy storage converter is switched from grid connection to off-grid operation, an off-grid enabling signal is generated, after the rising edge delay A13 passes through the parameter T3, the output of the OR gate A17 is 1, the RS register A10 is set to 0, the output switching signal is changed to 0, and the phase angle synchronous signal is changed to be generated at a fixed grid phase angle;
(3) when the energy storage converter is switched from off-grid to grid operation, an off-grid enabling signal is cleared, after the falling edge time delay A10 passes through the parameter T2, the output of the AND gate A12 is 1, the RS register A18 is set to be 1, and a phase angle synchronous signal is generated by the actual phase angle of the power grid;
(4) the energy storage converter operates under the condition that no power grid exists and off-grid operation needs to be started, the comparator A15 compares the power grid amplitude with the parameter K5, meanwhile, no off-grid enabling signal exists, the AND gate A16 outputs 1, the RS register A18 is set to 0 and 0, and the phase angle synchronous signal is changed into the fixed power grid phase angle to be generated;
the parameter T2 is set according to the time from off-grid switching to grid connection; the parameter T3 is smaller than the grid period of 20ms.
The method for generating off-network enabling signals by the enabling output unit comprises the following three modes:
the method comprises the steps that a power grid voltage signal is collected, and the power grid voltage signal enters an average value operation circuit and a logic operation circuit to be operated after passing through a voltage sampling circuit and an AD conversion circuit, and then an off-grid enabling signal is output;
secondly, receiving an off-network enabling signal issued by the upper computer through the DP port circuit, and analyzing the off-network enabling signal through the DP protocol circuit;
acquiring a signal of switching off of a high-voltage cabinet switch by using an I/O port circuit, and outputting an off-grid enabling signal after processing the signal by a signal processing circuit;
and finally, performing OR logic operation on the off-grid enabling signals obtained in the three modes by an OR gate, and sending signals to the energy storage converter through the optical fiber output ports of the corresponding enabling output units.
The specific implementation method of the step 3 is as follows: each energy storage converter receives the phase angle synchronous signal, and produces a phase angle corresponding to the frequency of the power grid through the controller, wherein the phase angle is 0 to 16383 and corresponds to 0 to 2 pi, the phase angle of off-grid voltage is calculated, and the off-grid voltage generated by all the energy storage converters receiving the phase angle synchronous signal is the same.
The phase angle output unit and the enabling output unit respectively output 12 paths of off-grid phase angle synchronous signals and 12 paths of off-grid enabling signals to the 12 energy storage converters.
The phase angle output unit and the enabling output unit respectively generate 12 paths of off-grid phase angle synchronous signals and 12 paths of off-grid enabling signals, wherein 11 paths of signals are output to 11 energy storage converters, and the other 1 path of signals are output to a control signal input circuit of the next-stage FPGA controller.
The invention has the advantages and positive effects that:
1. the control method ensures that the energy storage converters can establish the same off-grid voltage by generating the off-grid synchronous phase angle signal and the off-grid enabling signal, ensures that the power grid phases and the frequencies of all the energy storage converters are completely the same, realizes that all the energy storage converters enter the off-grid running state at the same time, ensures that the power grid is stable, and does not have power failure in load. Meanwhile, the power grid vibration caused by the fact that each energy storage converter carries out self frequency adjustment and the power grid breakdown caused by overlarge single-machine load caused by the fact that the energy storage converters cannot be cut into and off the grid at the same time can be avoided.
2. The control method improves the stability of the power grid when the energy storage converter is switched into off-grid operation from grid-connected operation, and can provide load power supply seamlessly and rapidly without causing power failure to influence the normal operation of the load.
3. The control method can be used for cascading and controlling hundreds of energy storage converters, so that the off-grid synchronous switching function of more energy storage converters is realized.
Drawings
FIG. 1 is a schematic diagram of a control device connection of the present invention;
FIG. 2 is a schematic circuit diagram of the main control board of the present invention;
FIG. 3 is a block diagram of the phase angle output unit circuit of the present invention;
FIG. 4 is a block diagram of a switch logic function module of the present invention;
FIG. 5 is a block diagram of the enable output unit circuit of the present invention;
FIG. 6 is a waveform diagram of a phase angle synchronization signal generated by the present invention;
fig. 7 is an expanded connection schematic of the present invention.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings.
A control method for realizing the off-grid synchronous switching function of a plurality of energy storage converters is realized on an off-grid synchronous switching control device of the plurality of energy storage converters shown in figure 1. The control device comprises a main control board and a power supply circuit for supplying power to the main control board, wherein the power supply circuit comprises two switch power supplies, two switches and two indicator lamps, the two switch power supplies are respectively connected with an external power supply through one switch, the external power supply can adopt 220V alternating current or 220V direct current, the two switch power supplies are 15V power supply output and the output ends of the two switch power supplies are connected to the main control board, and the two indicator lamps are respectively connected to the output ends of the two switch power supplies and are used for indicating the states of the switch power supplies.
As shown in fig. 2, the main control board comprises an FPGA controller, and a phase angle output unit, an enabling output unit, a DP port circuit, a voltage sampling circuit, an I/O port circuit and an optical fiber input port connected with the FPGA controller, wherein the DP port circuit, the voltage sampling circuit, the I/O port circuit and the optical fiber input port form a control signal input circuit and are connected with the FPGA controller, the phase angle output unit comprises 12 optical fiber output ports, the enabling output unit comprises 12 optical fiber output ports, the FPGA controller is connected with the phase angle output unit to realize 12 paths of phase angle signal output functions, the FPGA controller is connected with the enabling output unit to realize 12 paths of enabling signal output functions, and each phase angle output port and each enabling output port are connected to corresponding input ports of 1 energy storage converter, so as to realize the off-grid synchronous switching function of the plurality of energy storage converters.
And the phase angle output unit generates an off-grid phase angle synchronous signal under the control of the FPGA controller. As shown in fig. 3, the phase angle output unit includes a comparator A1, a counter A2, a comparator A3, a comparator A4, a monostable register A5, a switching logic module A6, and a comparator A7. Two input ports of the comparator A1 are respectively connected with the parameter K1 and an output port of the counter A2, and the output port of the comparator A1 is connected with a reset port of the counter A2; the preset number port of the counter A2 is connected with a power grid phase angle signal, the setting enabling port of the counter A2 is connected with an off-grid enabling signal, the clock port of the counter A2 is connected with a 40MHz clock, the output port of the counter A2 is respectively connected with one input port of the comparator A1 and one input port of the comparator A3, and the other input end of the comparator A3 is connected with the parameter K2; two input ports of the comparator A4 are respectively connected with a power grid phase angle signal and a parameter K3, and the output end of the comparator A4 is connected with the input end of the monostable register A5; the two input ends of the switching logic module A6 are respectively connected with a power grid amplitude signal and an off-grid enabling signal, the output end of the switching logic module A6, the output end of the monostable register A5 and the output end of the comparator A3 are respectively connected with the input end of the comparator A7, and the output end of the comparator A7 outputs an off-grid phase angle synchronous signal.
As shown in fig. 4, the switching logic module A6 includes a comparator A9, a falling edge delay a10, an not gate a11, an and gate a12, a rising edge delay a13, an not gate a14, a comparator a15, an and gate a16, an or gate a17, and an RS register a18. Two input ends of the comparator A9 are respectively connected with a power grid amplitude signal and a parameter K4; the input end of the falling edge delayer A10 is connected with an off-network enabling signal, the output end of the falling edge delayer A10 is connected with an NOT gate A11, the output end of the NOT gate A11 and the output end of the comparator A9 are respectively connected to two input ends of an AND gate A12, and the output end of the AND gate A12 is connected with the S input end of an RS register A18; the input end of the rising edge delayer A13 is connected with an off-network enabling signal, and the output end of the rising edge delayer A13 is connected with one input end of the OR gate A17; the input end of the NOT gate A14 is connected with an off-grid enabling signal, and the output end of the NOT gate A14 is connected to one input end of the AND gate A16; two input ends of the comparator A15 are respectively connected with a power grid amplitude signal and a parameter K5, and an output end of the comparator A15 is connected to the other input end of the AND gate A16; the output end of the AND gate A16 and the output end of the rising edge delay A13 are respectively connected with two input ends of the OR gate A17, the output end of the OR gate A17 is connected with the R input end of the RS register A18, and the output end of the RS register A18 outputs a switching signal Q.
In the above module, the parameter K1 is set to correspond to the period of the power grid (the frequency is 50Hz of the power grid, for 20ms of the period of the power grid, K1 is set to 800000), the parameter K2 is the pulse width corresponding to the high level, the parameter K3 is the minimum detection value of the zero time of the phase angle of the power grid, the parameter T1 is the high level duration of the phase angle synchronous signal, the parameter K4 is the minimum alternating voltage of the normal operation of the energy storage converter, and the parameter K5 is the coefficient for judging the no power of the power grid.
As shown in fig. 5, the enable output unit includes an average value operation circuit, a logic operation circuit, a DP protocol analysis circuit, a signal processing circuit, and an or gate. The input end of the average value operation circuit is connected with a voltage sampling circuit through an AD conversion circuit, the voltage sampling circuit is connected with an external power grid voltage to collect three-phase voltages UA, UB and UC, and the output end of the average value operation circuit is connected with a logic operation circuit; the DP protocol analysis circuit receives external DP data through the DP port circuit and analyzes the DP data; the signal processing circuit receives a switch-off signal of the high-voltage cabinet through the I/O port circuit; the output end of the logic operation circuit, the output end of the protocol analysis circuit and the output of the signal processing circuit are respectively connected with the input end of an OR gate, and the OR gate outputs an off-network enabling signal.
Because the FPGA has parallel output capability, the synchronous time error is in nanosecond level, which is far smaller than the control period of the energy storage converters, the frequency difference of the output voltage can not be caused, the phase angle synchronous signals received by each energy storage converter are identical, the generated electrical angles are identical, and the calculated off-grid voltage phase angles are identical.
Based on the above-mentioned off-grid synchronous switching control device of multiple energy storage converters, the invention provides a control method for realizing the off-grid synchronous switching function of multiple energy storage converters, comprising the following steps:
and step 1, an FPGA controller of the off-grid synchronous switching control device of the plurality of energy storage converters receives a power grid phase angle signal, a power grid amplitude signal and an off-grid enabling signal through a control signal input circuit.
In the step, the off-grid synchronous switching control device of the energy storage converters is connected with an external power grid, an upper computer and a high-voltage cabinet through a control signal input port and acquires a power grid phase angle signal, a power grid amplitude signal and an off-grid enabling signal.
And 2, generating off-grid phase angle synchronous signals and off-grid enabling signals by the FPGA controller of the off-grid synchronous switching control device of the plurality of energy storage converters through the phase angle output unit and the enabling output unit, and outputting the off-grid phase angle synchronous signals and the off-grid enabling signals to the plurality of energy storage converters at the same time.
The specific implementation method of the steps is as follows:
step 2.1, the phase angle output unit generates an off-grid phase angle synchronous signal under the control of the FPGA controller, and the specific method comprises the following steps:
in a comparator A1, when the output value of a counter A2 is larger than a parameter K1, the counter A2 is reset, counting is started from 0, and the counter A2 is counted circularly to generate a phase angle signal with fixed power grid frequency, the counter A2 can be counted by the rising edge of an off-grid enabling signal, the power grid phase angle is arranged in the counter A2, the counter A2 starts counting from the current power grid phase angle, tracking of the power grid phase angle is realized by the output phase angle, when the output value of the counter A2 is smaller than the parameter K2, the comparator A3 outputs a high level, and then the comparator A3 outputs a synchronous phase angle signal with fixed power grid frequency to the comparator A7;
secondly, the comparator A4 and the monostable register A5 generate phase angle synchronous signals according to the actual power grid phase angle, the comparator A4 compares the power grid phase angle with the parameter K3 to judge the zero crossing position of the actual power grid phase angle, and the monostable register A5 generates high-level signals of the parameter T1 time so as to obtain the synchronous signals of the actual power grid phase angle and output the synchronous signals to the comparator A7;
according to the switching logic generated by the power grid amplitude and the off-grid enabling signal, the switching logic module A6 realizes the switching of the actual power grid phase angle and the fixed power grid phase angle through the comparator A7.
The specific switching method of the switching logic module A6 is as follows:
(1) when the energy storage converter operates in a grid-connected state, no off-grid enabling signal exists, a phase angle synchronous signal is generated by an actual power grid phase angle, a comparator A9 compares the power grid amplitude with a parameter K4, the off-grid enabling signal is 0, an RS register A18 is set to be 1, and an output switching signal is 1;
(2) when the energy storage converter is switched from grid connection to off-grid operation, an off-grid enabling signal is generated, after the rising edge delay A13 passes through a parameter T3 (T3 is smaller than 20ms of a power grid period), the output of an OR gate A17 is 1, an RS register A10 is set to 0, the output switching signal becomes 0, and a phase angle synchronous signal becomes a fixed power grid phase angle to generate;
(3) when the energy storage converter is switched from off-grid to grid operation, an off-grid enabling signal is cleared, a falling edge delayer A10 passes through a parameter T2 (T2 can be set according to the time of switching from off-grid to grid), an AND gate A12 outputs 1, an RS register A18 is set to 1, and a phase angle synchronous signal is generated by an actual power grid phase angle;
(4) the energy storage converter operates under the condition that no power grid exists and off-grid operation needs to be started, the comparator A15 compares the power grid amplitude with the parameter K5, meanwhile, no off-grid enabling signal exists, the AND gate A16 outputs 1, the RS register A18 is set to 0 and 0, and the phase angle synchronous signal is changed into the fixed power grid phase angle to be generated.
The phase angle synchronous signals selected by the switching logic module are output to 12 paths of optical fiber ports of the phase angle output unit through corresponding pins of the FPGA controller, and reach the energy storage converter through optical fibers connected with the energy storage converter. Because the FPGA controller has parallel output capability, the consistency of output signals can be ensured, and the synchronous time error is in nanosecond level and is far smaller than the control period of the energy storage converter, so that the frequency difference of output voltage can not be caused.
Step 2.2, the enabling output unit outputs multipath off-network enabling signals under the control of the FPGA controller, wherein the following three modes are included:
the method comprises the steps that a grid voltage signal is collected, the grid voltage signal enters an FPGA average value operation circuit after passing through a voltage sampling circuit and an AD conversion circuit on a main control board, and an off-grid enabling signal is calculated through logic operation of an FPGA controller;
secondly, receiving an off-network enabling signal issued by an upper computer through a DP port circuit (Profibus-DP port), and analyzing the off-network enabling signal through a DP protocol circuit of the FPGA controller;
the method comprises the steps of collecting a signal of switching off of a high-voltage cabinet by using an I/O port circuit, processing the signal by a signal processing circuit of an FPGA controller, and outputting the processed signal to obtain an off-grid enabling signal.
The OR gate of the enabling output unit carries out OR logic operation on the 3 signals, and if only one signal is changed to be high level, the optical fiber output port of the corresponding enabling output unit sends the signal to the energy storage converter.
And 3, generating an off-grid phase angle of the energy storage converters after the plurality of energy storage converters receive the off-grid phase angle synchronous signals, and switching the energy storage converters into an off-grid running state after the plurality of energy storage converters receive the off-grid enabling signals.
In the step, the off-grid phase angle synchronous signal output by the control device is output to the energy storage converter, and the energy storage converter receives the phase angle synchronous signal and generates the self off-grid phase angle. As shown in fig. 6, each energy storage converter receives a phase angle synchronization signal, and generates a phase angle corresponding to the frequency of the power grid through the controller, wherein the phase angle is 0 to 16383, which corresponds to 0 to 2 pi, the phase angle of the off-grid voltage is calculated, each energy storage converter generates a corresponding off-grid voltage according to the off-grid phase angle, and because the phase angle synchronization signals received by each energy storage converter are identical, the generated electrical angles are identical, and the calculated off-grid voltage phase angles also have to be identical. Therefore, the off-grid voltages generated by all the energy storage converters receiving the phase angle synchronization are the same, and the large-scale off-grid operation is satisfied.
After the energy storage converters receive the off-grid enabling signals, all the energy storage converters receiving the off-grid enabling signals are simultaneously switched into an off-grid running state.
In addition, the phase angle output unit and the enabling output unit can output 12 paths of off-grid phase angle synchronous signals and 12 paths of off-grid enabling signals respectively. The 12-channel off-grid phase angle synchronous signals and the 12-channel off-grid enabling signals can be output to the 12 energy storage converters to control the energy storage converters, the 11-channel signals can be output to the 11 energy storage converters to control the energy storage converters, and the other-channel signals are output to the off-grid synchronous switching control device of the next-stage energy storage converters, so that the cascade function is realized. As shown in fig. 7, one output port of the phase angle signal output unit of one main control board and one output port of the enabling output unit are connected to the optical fiber input port of the main control board of the next stage, so that the two control devices share 23 paths of phase angle synchronous signals and 23 paths of off-grid enabling signals. And so on, more device extensions can be made, up to hundreds of output ports. The calculation formula of the number of the energy storage converters corresponding to each group of ports is as follows:
P＝12+(n-1)×11
wherein P is the number of output ports, and n is the number of control devices.
It should be emphasized that the examples described herein are illustrative rather than limiting, and therefore the invention includes, but is not limited to, the examples described in the detailed description, as other embodiments derived from the technical solutions of the invention by a person skilled in the art are equally within the scope of the invention.
Claims (7)
1. A control method for realizing off-grid synchronous switching function of a plurality of energy storage converters is characterized by comprising the following steps: the method comprises the following steps:
step 1, an FPGA controller receives a power grid phase angle signal, a power grid amplitude signal and an off-grid enabling signal through a control signal input circuit;
step 2, the FPGA controller generates an off-grid phase angle synchronous signal and an off-grid enabling signal through a phase angle output unit and an enabling output unit and outputs the off-grid phase angle synchronous signal and the off-grid enabling signal to a plurality of energy storage converters at the same time;
step 3, the energy storage converters receive the off-grid phase angle synchronous signals and generate own off-grid phase angles, and the energy storage converters receive off-grid enabling signals and then switch into an off-grid running state;
the phase angle output unit comprises a phase angle output unit and comprises a comparator A1, a counter A2, a comparator A3, a comparator A4, a monostable register A5, a switching logic module A6 and a comparator A7, and the generation method of the phase angle output unit comprises the following steps:
in a comparator A1, when the output value of a counter A2 is larger than a parameter K1, the counter A2 is reset, counting is started from 0, and the counter A2 is counted circularly to generate a phase angle signal with fixed power grid frequency, the counter A2 can be counted by the rising edge of an off-grid enabling signal, the power grid phase angle is arranged in the counter A2, the counter A2 starts counting from the current power grid phase angle, tracking of the power grid phase angle is realized by the output phase angle, when the output value of the counter A2 is smaller than the parameter K2, the comparator A3 outputs a high level, and then the comparator A3 outputs a synchronous phase angle signal with fixed power grid frequency to the comparator A7;
secondly, the comparator A4 and the monostable register A5 generate phase angle synchronous signals according to the actual power grid phase angle, the comparator A4 compares the power grid phase angle with the parameter K3 to judge the zero crossing position of the actual power grid phase angle, and the monostable register A5 generates high-level signals of the parameter T1 time so as to obtain the synchronous signals of the actual power grid phase angle and output the synchronous signals to the comparator A7;
thirdly, the switching logic module A6 realizes the switching of the actual power grid phase angle and the fixed power grid phase angle through the comparator A7 according to the switching logic generated by the power grid amplitude and the off-grid enabling signal;
the parameter K1 is a power grid period, the parameter K2 is a pulse width of a high level, the parameter K3 is a minimum detection value when a power grid phase angle is zero, and the parameter T1 is a high level duration of a phase angle synchronous signal.
2. The control method for realizing the off-grid synchronous switching function of a plurality of energy storage converters according to claim 1, wherein the control method comprises the following steps: and step 1, acquiring a power grid phase angle signal, a power grid amplitude signal and an off-grid enabling signal through an external power grid, an upper computer and a high-voltage switch cabinet.
3. The control method for realizing the off-grid synchronous switching function of a plurality of energy storage converters according to claim 1, wherein the control method comprises the following steps: the switching logic module A6 includes a comparator A9, a falling edge delay a10, an not gate a11, an and gate a12, a rising edge delay a13, an not gate a14, a comparator a15, an and gate a16, an or gate a17 and an RS register a18, and the switching implementation method of the switching logic module is as follows:
(1) when the energy storage converter operates in a grid-connected state, no off-grid enabling signal exists, a phase angle synchronous signal is generated by an actual power grid phase angle, a comparator A9 compares the power grid amplitude with a parameter K4, the off-grid enabling signal is 0, an RS register A18 is set to be 1, and an output switching signal is 1;
(2) when the energy storage converter is switched from grid connection to off-grid operation, an off-grid enabling signal is generated, after the rising edge delay A13 passes through the parameter T3, the output of the OR gate A17 is 1, the RS register A10 is set to 0, the output switching signal is changed to 0, and the phase angle synchronous signal is changed to be generated at a fixed grid phase angle;
(3) when the energy storage converter is switched from off-grid to grid operation, an off-grid enabling signal is cleared, after the falling edge time delay A10 passes through the parameter T2, the output of the AND gate A12 is 1, the RS register A18 is set to be 1, and a phase angle synchronous signal is generated by the actual phase angle of the power grid;
(4) the energy storage converter operates under the condition that no power grid exists and off-grid operation needs to be started, the comparator A15 compares the power grid amplitude with the parameter K5, meanwhile, no off-grid enabling signal exists, the AND gate A16 outputs 1, the RS register A18 is set to 0, and the phase angle synchronous signal is changed into the fixed power grid phase angle to be generated;
the parameter T2 is set according to the time from off-grid switching to grid connection; the parameter T3 is smaller than the grid period of 20ms.
4. The control method for realizing the off-grid synchronous switching function of a plurality of energy storage converters according to claim 1, wherein the control method comprises the following steps: the method for generating off-network enabling signals by the enabling output unit comprises the following three modes:
the method comprises the steps that a power grid voltage signal is collected, and the power grid voltage signal enters an average value operation circuit and a logic operation circuit to be operated after passing through a voltage sampling circuit and an AD conversion circuit, and then an off-grid enabling signal is output;
secondly, receiving an off-network enabling signal issued by the upper computer through the DP port circuit, and analyzing the off-network enabling signal through the DP protocol circuit;
acquiring a signal of switching off of a high-voltage cabinet switch by using an I/O port circuit, and outputting an off-grid enabling signal after processing the signal by a signal processing circuit;
and finally, performing OR logic operation on the off-grid enabling signals obtained in the three modes by an OR gate, and sending signals to the energy storage converter through the optical fiber output ports of the corresponding enabling output units.
5. The control method for realizing the off-grid synchronous switching function of a plurality of energy storage converters according to claim 1, wherein the control method comprises the following steps: the specific implementation method of the step 3 is as follows: each energy storage converter receives the phase angle synchronous signal, and produces a phase angle corresponding to the frequency of the power grid through the controller, wherein the phase angle is 0 to 16383 and corresponds to 0 to 2 pi, the phase angle of off-grid voltage is calculated, and the off-grid voltage generated by all the energy storage converters receiving the phase angle synchronous signal is the same.
6. The control method for implementing off-grid synchronous switching function of multiple energy storage converters according to any one of claims 1 to 5, wherein the method comprises the following steps: the phase angle output unit and the enabling output unit respectively output 12 paths of off-grid phase angle synchronous signals and 12 paths of off-grid enabling signals to the 12 energy storage converters.
7. The control method for implementing off-grid synchronous switching function of multiple energy storage converters according to any one of claims 1 to 5, wherein the method comprises the following steps: the phase angle output unit and the enabling output unit respectively generate 12 paths of off-grid phase angle synchronous signals and 12 paths of off-grid enabling signals, wherein 11 paths of signals are output to 11 energy storage converters, and the other 1 path of signals are output to a control signal input circuit of the next-stage FPGA controller.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103560535A (en) * | 2013-11-20 | 2014-02-05 | 北京四方继保自动化股份有限公司 | Micro-grid operation mode seamless switching method based on energy storage current transformer |
| WO2015070493A1 (en) * | 2013-11-15 | 2015-05-21 | 许继电气股份有限公司 | Island switching control method for modular multi-level converter |
| WO2015096586A1 (en) * | 2013-12-24 | 2015-07-02 | 中国西电电气股份有限公司 | Seamless switching method and system for micro-grid system |
| CN106771879A (en) * | 2017-01-18 | 2017-05-31 | 阳光电源股份有限公司 | A kind of electric network state detecting method, device and static switching switch cubicle |
| CN108039716A (en) * | 2017-12-25 | 2018-05-15 | 上海电气集团股份有限公司 | A kind of control system and method based on intelligent micro-grid |
-
2020
- 2020-03-20 CN CN202010199990.1A patent/CN111463832B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2015070493A1 (en) * | 2013-11-15 | 2015-05-21 | 许继电气股份有限公司 | Island switching control method for modular multi-level converter |
| CN103560535A (en) * | 2013-11-20 | 2014-02-05 | 北京四方继保自动化股份有限公司 | Micro-grid operation mode seamless switching method based on energy storage current transformer |
| WO2015096586A1 (en) * | 2013-12-24 | 2015-07-02 | 中国西电电气股份有限公司 | Seamless switching method and system for micro-grid system |
| CN106771879A (en) * | 2017-01-18 | 2017-05-31 | 阳光电源股份有限公司 | A kind of electric network state detecting method, device and static switching switch cubicle |
| CN108039716A (en) * | 2017-12-25 | 2018-05-15 | 上海电气集团股份有限公司 | A kind of control system and method based on intelligent micro-grid |
Non-Patent Citations (1)
| Title |
|---|
| 唐酿 ; 盛超 ; 赵天扬 ; 袁敞 ; .虚拟同步发电机并离网无缝切换控制策略研究.可再生能源.2016,(11),全文. * |
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