CN117648804A - Impedance design method for new energy hydrogen production equipment - Google Patents
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- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 title claims abstract description 50
- 229910052739 hydrogen Inorganic materials 0.000 title claims abstract description 50
- 239000001257 hydrogen Substances 0.000 title claims abstract description 50
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 48
- 238000000034 method Methods 0.000 title claims abstract description 30
- 238000013461 design Methods 0.000 title claims abstract description 18
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 22
- 238000013178 mathematical model Methods 0.000 claims abstract description 8
- 230000004044 response Effects 0.000 claims description 19
- 238000005868 electrolysis reaction Methods 0.000 claims description 12
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- 239000003990 capacitor Substances 0.000 claims description 8
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- 238000012360 testing method Methods 0.000 claims description 6
- 230000009466 transformation Effects 0.000 claims description 5
- 238000004364 calculation method Methods 0.000 claims description 3
- 230000003071 parasitic effect Effects 0.000 claims description 3
- 239000013598 vector Substances 0.000 claims description 3
- 238000011217 control strategy Methods 0.000 claims description 2
- 230000010363 phase shift Effects 0.000 claims description 2
- 230000001629 suppression Effects 0.000 claims description 2
- 238000010998 test method Methods 0.000 claims description 2
- 230000010355 oscillation Effects 0.000 description 7
- 230000007246 mechanism Effects 0.000 description 4
- 230000001808 coupling effect Effects 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 230000005611 electricity Effects 0.000 description 2
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- 238000004458 analytical method Methods 0.000 description 1
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- 239000011159 matrix material Substances 0.000 description 1
- 238000000819 phase cycle Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
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- 230000006641 stabilisation Effects 0.000 description 1
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/30—Hydrogen technology
- Y02E60/36—Hydrogen production from non-carbon containing sources, e.g. by water electrolysis
Abstract
The invention discloses a new energy hydrogen production equipment impedance design method, which comprises the following steps: step S1, establishing electrolytic water hydrogen production equipment comprising an electrolytic tank stack and a power electronic hydrogen production converter; s2, establishing an electrolytic cell model on the basis of an equivalent RC network of an equivalent electrolytic cell; s3, simplifying the sequence impedance modeling of the MMC, and establishing a mathematical model of a single-arm MMC average model; and S4, establishing a rectifier sequence impedance model by adopting a multi-harmonic linearization method, adding the rectifier sequence impedance model into an electrolytic tank impedance model, and finally obtaining an electrolytic water hydrogen production rectifying equipment impedance model.
Description
Technical Field
The invention relates to the technical field of hydrogen production equipment impedance, in particular to a new energy hydrogen production equipment impedance design method.
Background
The world is experiencing an unprecedented major bureau of energy technology, and the rapid development of energy technology brings about unprecedented competition. Under the background, china is greatly propelled to develop renewable energy, a novel power system characterized by clean energy supply and energy consumption and electricity is urgent, and the form of the Chinese power system is deeply changed by clean energy represented by wind and light. On one hand, the light energy and wind energy are utilized to generate electricity, and surplus electric energy is converted into hydrogen energy through water electrolysis to be stored, so that the method is an ideal outlet for future energy development; on the other hand, wind power and photovoltaic are connected into a power grid through a power electronic converter, and the duty ratio of power electronic equipment at the power supply side is continuously improved. Therefore, "high proportion renewable energy sources" and "high proportion power electronics" are the main trends of power systems.
However, the "dual high" power system stabilization mechanism is complex and safe and stable operation faces significant challenges. On the one hand, discontinuous links or nonlinear links such as a switch, a dead zone, a switch, a limiting and the like commonly exist in the power electronic equipment and a control loop thereof, and the influence of the links on the stability and the dynamic characteristics of the system is difficult to evaluate, so that the dynamic complexity of the power system is further increased. On the other hand, because the wind energy and solar energy resource concentrated areas are far away from the main network, the local power network presents weak power network characteristics, and after large-scale power electronic equipment is connected into the weak power network, the stability margin can be reduced, and the system resonance and even the instability phenomenon can be easily caused. At present, many times of oscillation accidents caused by the access of a large number of power electronic devices occur worldwide.
The impedance method plays a significant role in analyzing the oscillation mechanism when the power electronic equipment is interconnected with the weak electric network. The literature provides a stability analysis method based on a phase sequence domain impedance matrix model, and theoretically reveals a generation mechanism of the oscillation frequency coupling phenomenon of the wind power converter; the literature derives impedance models of the doubly-fed wind power plant and the soft direct wind power plant side converter station respectively, builds a doubly-fed fan model taking a phase-locked loop into consideration, and analyzes the mechanism of system subsynchronous oscillation and the influence of phase-locked loop parameters on system oscillation characteristics; the literature analyzes modeling and control of an N parallel grid-connected inverter adopting an LCL filter in a photovoltaic power station, and describes a coupling effect caused by grid impedance.
Aiming at the problem of modeling impedance of a hydrogen production system by electrolysis of water under a weak current network, an electric sub-model of the electrolysis cell is built by utilizing the theory of a circuit and a control system based on an equivalent RC network of the electrolysis cell, starting from the step response characteristic (such as rise time and sedimentation time) of the electrolysis cell; then, an impedance model of the electrolytic water hydrogen production equipment including the thyristor rectifier bridge and the control thereof is established through the mapping function.
Disclosure of Invention
The invention aims to solve the technical problem that oscillation instability exists when a high-power electronic new energy hydrogen production system is interconnected with a power grid, and the impedance design method of the new energy hydrogen production equipment is used for determining the impedance of the water electrolysis hydrogen production equipment under the condition of comprehensively considering a power electronic converter and an electrolytic tank, so that the stability of the grid-connected system of the water electrolysis hydrogen production equipment can be accurately analyzed.
In order to solve the technical problems, the invention adopts the following technical scheme:
the new energy hydrogen production equipment impedance design method comprises the following steps:
step S1, an electrolytic water hydrogen production device comprising an electrolytic tank stack and a power electronic hydrogen production converter is established, wherein the electrolytic tank is a PEM type electrolytic tank, the hydrogen production converter is a modular multilevel converter MMC rectifying device, and the MMC rectifying device adopts bridge arm voltage balance control, module voltage balance control, circulation suppression control strategy and carrier phase shift modulation to stably control the working point of the electrolytic tank;
step S2, on the basis of an equivalent RC network of an equivalent electrolytic cell, establishing an electrolytic cell model according to a stacking current and time curve obtained by a step-down experimental test of the electrolytic cell, and simultaneously, applying a control system theory and Laplace transformation to establish the electrolytic cell model;
s3, establishing a mathematical model of a single-arm MMC average model to simplify the sequence impedance modeling of the MMC;
and S4, establishing a PQ mode MMC sequence impedance model by adopting a multiple harmonic linearization method, establishing a small signal linear model of a nonlinear system by calculating small signal current response under corresponding voltage disturbance, and adding the small signal linear model into an electrolytic tank impedance model to finally obtain the impedance model of the water electrolysis hydrogen production equipment.
The technical scheme of the invention is further improved as follows: the MMC rectifying device in the step S1 comprises three phases, each phase is divided into an upper bridge arm and a lower bridge arm, wherein each bridge arm comprises N identical half-bridge sub-modules which are connected in series, L 0 And R is 0 Respectively representing the inductance and parasitic resistance of the bridge arm, I dc And V dc For DC side current and voltage, L d And C d The filter inductor and the filter capacitor are respectively arranged on the direct current side.
The technical scheme of the invention is further improved as follows: in the step S1, the MMC rectifying device adopts a double closed-loop control mode, so as to realize accurate control of the voltage and the current of the direct current side.
The technical scheme of the invention is further improved as follows: the specific operation of the step 2 is as follows:
obtaining the overall ramp up/down step response of the alkaline and PEM electrolytic battery according to the battery experimental test method; according to the control system theory, the alkaline stack current, i, passes through a voltage V relative to the input voltage t Is represented by a second order transfer function in which there are two real poles to the left of the complex plane, as follows:
wherein s1=p1, s2=p2, p1, p2<0 (|p1| > |p2|) is the pole of the cell transfer function; i(s) and Vt(s) are respectively Laplacian transformation of the current and the voltage of the electrolytic cell; trP and tsP are obtained from the measured values, then p1 and p2 are calculated from the following formula:
wherein 0.05 corresponds to a 5% quasi-steady state error in the stack current response at tsP and 0.5 corresponds to a 50% response value at trP; then, according to the pole calculation, a Gp(s) function is obtained; in order to obtain a viable circuit representation from any transfer function, the step difference between its numerator and denominator must be at most one, so the circuit representation of the PEM stack cannot be obtained from Gp(s) because its step difference between the numerator and denominator is 2; therefore, it is necessary to operate on Gp(s) so that the response of the modified transfer function Gmp(s) is as close as possible to that of Gp(s) while reducing the step difference between its numerator and denominator to 1; in particular by appropriately placing zeros in Gp(s), it is assumed that Gmp(s) is a modified version of Gp(s) that it includes one zero, namely:
the zero and the pole are calculated by the theory of the control system, and:
for PEM electrolysers, since the values of trP and tsP are small, one of the poles p1 is very far from the imaginary axis, which makes ls≡0, i.e. Ls can be ignored, then:
the equivalent input impedance to the PEM electrolyzer is obtained as:
when s=0, the double-layer capacitor is considered to be open, and the direct-current voltage source Vrev is equivalent to a resistor Vrev/Idc;
combining the direct current side filter circuit to obtain the direct current port impedance ZDC(s) of the electrolytic water hydrogen production equipment, which is expressed as,
the technical scheme of the invention is further improved as follows: the mathematical model of the single-arm MMC average model in step S3 is expressed as:
V mmc ＝m xu v xu
wherein V is mmc For series sub-module output voltage v xu For battery capacitance voltage, C m Is equivalent arm capacitance, i xu For upper arm current, m xu Is an upper arm index;
the arm current of MMC is divided into common mode CM component and differential mode DM component; the CM component of the upper arm current and the CM component of the lower arm current have identical amplitude and phase to form a circular current; the DM components of the upper arm current and the lower arm current have the same amplitude and opposite phases to form an output current; the same arm index has the same characteristics; the output current and the circulating current are expressed as:
i x ＝-i xu +i xl
according to the power circuit equations for the upper and lower arms, the upper arm current is expressed as:
based on the above equation, the output current is expressed as:
thus, the power level model of an MMC is equivalent to the upper arm model of an MMC.
The technical scheme of the invention is further improved as follows: the power level frequency domain small signal linear model in the step S4 is expressed as:
wherein I, V and M are matrices developed by steady-state harmonic vectors I, V and M, and are steady-state harmonic of arm current, arm index and capacitor voltage respectively; according to the control diagram, a control model of the MMC is established, and the control model of the MMC is expressed as follows:
in which Q i And Q c The coefficient matrixes of the phase current and the circulation control model are respectively expressed and are (2n+1) multiplied by (2n+1); q (Q) PLL And Q ol Representing phase-locked loop responseInfluence of MMC outer ring on impedance characteristics; since the order of harmonics in the arm current is infinite, theoretically Q i And Q c Are matrices with infinite order; phase current control and circulating current control are implemented in dq frames; assume that the phase current controller and the loop current controller are respectively expressed as:
wherein H is i (s) is the decoupling gain K d Phase current controller of H ic (s) is the decoupling gain K dc A circulating current controller of (2);
the phase-locked loop controller is in the form of:
substituting an MMC power level model, an MMC control model and an electrolytic tank impedance model of equivalent capacitance charging dynamics, wherein the electrolytic tank impedance model is a direct current port impedance ZDC(s) model of electrolytic water hydrogen production equipment, and then modeling the small signal response of the arm current to the alternating current end voltage disturbance is as follows:
Y＝(U+Y l ·Z dc ·(MZ c M+(MZ c I+V)(Q i +Q c ))) -1 ·(-Y l ·Z dc ·(MZ c I+V)(Q PLL +Q ol ))
the final positive and negative sequence impedance model of the hydrogen production device is:
wherein Y (n+1 ) is the (n+1 ) element of Y.
By adopting the technical scheme, the invention has the following technical progress:
1. the invention designs a new energy hydrogen production equipment impedance design method, which aims at the problem of oscillation instability when a high-power electronic new energy hydrogen production system is interconnected with a power grid.
2. The invention designs a new energy hydrogen production equipment impedance design method, which aims at accurately modeling impedance of an electrolytic tank with complex chemical characteristics, and establishes an electrolytic tank model by applying a stacking current and time curve obtained by an electrolytic tank depressurization experimental test.
3. The invention designs a new energy hydrogen production equipment impedance design method, which aims at solving the problem that complicated phase inversion process, high nonlinear characteristics and frequency coupling effect introduced by a control link cause difficulty in accurate modeling, simplifies MMC sequence impedance modeling, establishes a mathematical model of a single-arm MMC average model, establishes a rectifier sequence impedance model by adopting a multi-harmonic linearization method and adds the rectifier sequence impedance model into an electrolytic tank impedance model, and finally obtains the electrolytic water hydrogen production rectifying equipment impedance model.
Drawings
FIG. 1 is a circuit and control block diagram of the water electrolysis hydrogen plant of the present invention;
FIG. 2 is a circuit diagram of a PEM electrolyzer used in the present invention.
Detailed Description
The invention is further illustrated by the following examples:
as shown in FIG. 1, the circuit and control structure diagram of the water electrolysis hydrogen production equipment of the invention comprises the following specific steps:
step S1, the electrolytic cell is a PEM type electrolytic cell, the hydrogen production converter is a Modular Multilevel Converter (MMC) rectifying device, and electrolytic water hydrogen production equipment comprising an electrolytic cell stack and a power electronic hydrogen production converter is built. And a double closed-loop control mode is adopted to realize accurate control of direct-current side voltage and current. The circuit structure of the MMC rectifying device is shown in FIG. 1, wherein the MMC rectifying device comprises three phases, each phase is divided into an upper bridge arm and a lower bridge arm, each bridge arm comprises N identical half-bridge sub-modules connected in series, L 0 And R is 0 Respectively representing the inductance and parasitic resistance of the bridge arm, I dc And V dc For DC side current and voltage, L d And C d The filter inductor and the filter capacitor are respectively arranged on the direct current side.
Step S2, on the basis of an equivalent RC network of an equivalent electrolytic cell, a method for establishing an electrolytic cell model according to a stack current and time curve obtained by testing a step-down experiment of the electrolytic cell, and simultaneously, applying a control system theory and Laplacian transformation to establish the electrolytic cell model, wherein the specific method comprises the following steps:
FIG. 2 shows a PEM electrolyzer circuit used in the present invention.
And establishing an electrolytic cell model by using a stacking current and time curve obtained by the electrolytic cell depressurization experimental test. The overall ramp up/down step response of alkaline and PEM electrolysis cells was obtained from the cell stack experimental tests.
According to the control system theory, the alkaline stack current i can be calculated relative to the input voltage V t Is represented by a second order transfer function in which there are two real poles to the left of the complex plane, as follows:
wherein s1=p1, s2=p2, p1, p2<0 (|p1| > |p2|) is the pole of the cell transfer function; i(s) and Vt(s) are Laplace transforms of cell current and voltage, respectively. trP and tsP are obtained from the measured values, then p1 and p2 can be calculated from the following formulas:
where 0.05 corresponds to a 5% quasi-steady state error in the stack current response at tsP and 0.5 corresponds to a 50% response value at trP. Then, gp(s) functions can be obtained from pole calculations. In order to obtain a viable circuit representation from any transfer function, the step difference between its numerator and denominator must be at most one. Therefore, we cannot obtain a circuit representation of the PEM stack from Gp(s) because the step difference between its numerator and denominator is 2. Therefore, it is necessary to operate on Gp(s) so that the response of the modified transfer function Gmp(s) is as close as possible to that of Gp(s) while reducing the step difference between its numerator and denominator to 1. This can be achieved by appropriately placing zeros in Gp(s). Let us assume that Gmp(s) is a modified version of Gp(s) that includes a zero. Namely:
by the theory of the control system, the zero point and the pole can be calculated, and:
for PEM cellsFor t, due to rP And t sP So that one of the poles (p 1) is very far from the imaginary axis, which makes ls≡0, i.e. Ls can be ignored, then:
thus, the equivalent input impedance of the PEM electrolyzer is obtained as:
at s=0, the double layer capacitance may be considered to be open, and the direct current voltage source Vrev may be equivalent to the resistance Vrev/Idc.
In summary, by combining the DC side filter circuit, the DC port impedance Zdc(s) of the electrolytic water hydrogen production device can be obtained, which can be expressed as,
step S3, establishing a mathematical model of a single-arm MMC average model to simplify the sequence impedance modeling of the MMC, wherein the specific operation is as follows:
the mathematical model of the single-arm MMC average model is expressed as:
V mmc ＝m xu v xu
wherein V is mmc For series sub-module output voltage v xu For battery capacitance voltage, C m Is equivalent arm capacitance, i xu For upper arm current, m xu Is an upper arm index;
the arm current of MMC is divided into common mode CM component and differential mode DM component; the CM component of the upper arm current and the CM component of the lower arm current have identical amplitude and phase to form a circular current; the DM components of the upper arm current and the lower arm current have the same amplitude and opposite phases to form an output current; the same arm index has the same characteristics; the output current and the circulating current are expressed as:
i x ＝-i xu +i xl
according to the power circuit equations for the upper and lower arms, the upper arm current is expressed as:
based on the above equation, the output current is expressed as:
thus, the power level model of an MMC is equivalent to the upper arm model of an MMC.
S4, establishing a PQ mode MMC sequence impedance model by adopting a multiple harmonic linearization method, establishing a small signal linear model of a nonlinear system by calculating small signal current response under corresponding voltage disturbance, and adding the small signal linear model into an electrolytic tank impedance model to finally obtain an electrolytic water hydrogen production equipment impedance model; the specific operation is as follows:
the power level frequency domain small signal linear model is expressed as:
wherein I, V and M are matrices developed by steady-state harmonic vectors I, V and M, and are steady-state harmonic of arm current, arm index and capacitor voltage respectively; according to the control diagram, a control model of the MMC is established, and the control model of the MMC is expressed as follows:
in which Q i And Q c The coefficient matrixes of the phase current and the circulation control model are respectively expressed and are (2n+1) multiplied by (2n+1); q (Q) PLL And Q ol The influence of the phase-locked loop along with the MMC outer ring on the impedance characteristic is represented; since the order of harmonics in the arm current is infinite, theoretically Q i And Q c Are matrices with infinite order; phase current control and circulating current control are implemented in dq frames; assume that the phase current controller and the loop current controller are respectively expressed as:
wherein H is i (s) is the decoupling gain K d Phase current controller of H ic (s) is the decoupling gain K dc A circulating current controller of (2);
the phase-locked loop controller is in the form of:
substituting an MMC power level model, an MMC control model and an electrolytic tank impedance model of equivalent capacitance charging dynamics, wherein the electrolytic tank impedance model is a direct current port impedance ZDC(s) model of electrolytic water hydrogen production equipment, and then modeling the small signal response of the arm current to the alternating current end voltage disturbance is as follows:
Y＝(U+Y l ·Z dc ·(MZ c M+(MZ c I+V)·(Q i +Q c ))) -1 ·(-Y l ·Z dc ·(MZ c I+V)(Q PLL +Q ol ))
the final positive and negative sequence impedance model of the hydrogen production device is:
wherein Y (n+1 ) is the (n+1 ) element of Y.
Claims (6)
1. The impedance design method of the new energy hydrogen production equipment is characterized by comprising the following steps of:
step S1, an electrolytic water hydrogen production device comprising an electrolytic tank stack and a power electronic hydrogen production converter is established, wherein the electrolytic tank is a PEM type electrolytic tank, the hydrogen production converter is a modular multilevel converter MMC rectifying device, and the MMC rectifying device adopts bridge arm voltage balance control, module voltage balance control, circulation suppression control strategy and carrier phase shift modulation to stably control the working point of the electrolytic tank;
step S2, on the basis of an equivalent RC network of an equivalent electrolytic cell, establishing an electrolytic cell model according to a stacking current and time curve obtained by a step-down experimental test of the electrolytic cell, and simultaneously, applying a control system theory and Laplace transformation to establish the electrolytic cell model;
s3, establishing a mathematical model of a single-arm MMC average model to simplify the sequence impedance modeling of the MMC;
and S4, establishing a PQ mode MMC sequence impedance model by adopting a multiple harmonic linearization method, establishing a small signal linear model of a nonlinear system by calculating small signal current response under corresponding voltage disturbance, and adding the small signal linear model into an electrolytic tank impedance model to finally obtain the impedance model of the water electrolysis hydrogen production equipment.
2. The new energy hydrogen production equipment impedance design method according to claim 1, wherein the method comprises the following steps: the MMC rectifying device in the step S1 comprises three phases, each phase is divided into an upper bridge arm and a lower bridge arm, wherein each bridge arm comprises N identical half-bridge sub-modules which are connected in series, L 0 And R is 0 Respectively representing the inductance and parasitic resistance of the bridge arm, I dc And V dc For DC side current and voltage, L d And C d The filter inductor and the filter capacitor are respectively arranged on the direct current side.
3. The new energy hydrogen production equipment impedance design method according to claim 2, wherein the method comprises the following steps: in the step S1, the MMC rectifying device adopts a double closed-loop control mode, so as to realize accurate control of the voltage and the current of the direct current side.
4. The new energy hydrogen production equipment impedance design method according to claim 1, wherein the method comprises the following steps: the specific operation of the step 2 is as follows:
obtaining the overall ramp up/down step response of the alkaline and PEM electrolytic battery according to the battery experimental test method; according to the control system theory, the alkaline stack current, i, passes through a voltage V relative to the input voltage t Is represented by a second order transfer function in which there are two real poles to the left of the complex plane, as follows:
wherein s1=p1, s2=p2, p1, p2<0 (|p1| > |p2|) is the pole of the cell transfer function; i(s) and Vt(s) are respectively Laplacian transformation of the current and the voltage of the electrolytic cell; trP and tsP are obtained from the measured values, then p1 and p2 are calculated from the following formula:
wherein 0.05 corresponds to a 5% quasi-steady state error in the stack current response at tsP and 0.5 corresponds to a 50% response value at trP; then, according to the pole calculation, a Gp(s) function is obtained; in order to obtain a viable circuit representation from any transfer function, the step difference between its numerator and denominator must be at most one, so the circuit representation of the PEM stack cannot be obtained from Gp(s) because its step difference between the numerator and denominator is 2; therefore, it is necessary to operate on Gp(s) so that the response of the modified transfer function Gmp(s) is as close as possible to that of Gp(s) while reducing the step difference between its numerator and denominator to 1; in particular by appropriately placing zeros in Gp(s), it is assumed that Gmp(s) is a modified version of Gp(s) that it includes one zero, namely:
the zero and the pole are calculated by the theory of the control system, and:
for PEM electrolysers, since the values of trP and tsP are small, one of the poles p1 is very far from the imaginary axis, which makes ls≡0, i.e. Ls can be ignored, then:
the equivalent input impedance to the PEM electrolyzer is obtained as:
when s=0, the double-layer capacitor is considered to be open, and the direct-current voltage source Vrev is equivalent to a resistor Vrev/Idc;
combining the direct current side filter circuit to obtain the direct current port impedance ZDC(s) of the electrolytic water hydrogen production equipment, which is expressed as,
5. the new energy hydrogen production equipment impedance design method according to claim 4, wherein the method comprises the following steps: the mathematical model of the single-arm MMC average model in step S3 is expressed as:
V mmc ＝m xu v xu
wherein V is mmc For series sub-module output voltage v xu For battery capacitance voltage, C m Is equivalent arm capacitance, i xu For upper arm current, m xu Is an upper arm index;
the arm current of MMC is divided into common mode CM component and differential mode DM component; the CM component of the upper arm current and the CM component of the lower arm current have identical amplitude and phase to form a circular current; the DM components of the upper arm current and the lower arm current have the same amplitude and opposite phases to form an output current; the same arm index has the same characteristics; the output current and the circulating current are expressed as:
i x ＝-i xu +i xl
according to the power circuit equations for the upper and lower arms, the upper arm current is expressed as:
based on the above equation, the output current is expressed as:
thus, the power level model of an MMC is equivalent to the upper arm model of an MMC.
6. The new energy hydrogen production equipment impedance design method according to claim 5, wherein the method comprises the following steps: the power level frequency domain small signal linear model in the step S4 is expressed as:
wherein I, V and M are matrices developed by steady-state harmonic vectors I, V and M, and are steady-state harmonic of arm current, arm index and capacitor voltage respectively; according to the control diagram, a control model of the MMC is established, and the control model of the MMC is expressed as follows:
in which Q i And Q c The coefficient matrixes of the phase current and the circulation control model are respectively expressed and are (2n+1) multiplied by (2n+1); q (Q) PLL And Q ol The influence of the phase-locked loop along with the MMC outer ring on the impedance characteristic is represented; since the order of harmonics in the arm current is infinite, theoretically Q i And Q c Are matrices with infinite order; phase current control and circulating current control are implemented in dq frames; assume that the phase current controller and the loop current controller are respectively expressed as:
wherein H is i (s) is the decoupling gain K d Phase current controller of H ic (s) is the decoupling gain K dc A circulating current controller of (2);
the phase-locked loop controller is in the form of:
substituting an MMC power level model, an MMC control model and an electrolytic tank impedance model of equivalent capacitance charging dynamics, wherein the electrolytic tank impedance model is a direct current port impedance ZDC(s) model of electrolytic water hydrogen production equipment, and then modeling the small signal response of the arm current to the alternating current end voltage disturbance is as follows:
Y＝(U+Y l ·Z dc ·(MZ c M+(MZ c I+V)·(Q i +Q c ))) -1 ·(-Y l ·Z dc ·(MZ c I+V)(Q PLL +Q ol ))
the final positive and negative sequence impedance model of the hydrogen production device is:
wherein Y (n+1 ) is the (n+1 ) element of Y.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102969924A (en) * | 2012-11-07 | 2013-03-13 | 燕山大学 | Novel voltage type multi-level inverter |
| CN112953172A (en) * | 2021-01-28 | 2021-06-11 | 东南大学 | Method for modeling sequence impedance of modular multilevel converter under phase-locked loop coupling |
| CN114481215A (en) * | 2022-01-10 | 2022-05-13 | 清华大学 | Electrolytic hydrogen production device and control method thereof |
| CN114908356A (en) * | 2021-02-09 | 2022-08-16 | 江苏和网源电气有限公司 | Renewable energy source water electrolysis hydrogen production control system |
| CN116896272A (en) * | 2023-06-07 | 2023-10-17 | 北方工业大学 | Control method and device for new energy water electrolysis hydrogen production power supply |
-
2023
- 2023-11-15 CN CN202311525146.3A patent/CN117648804A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102969924A (en) * | 2012-11-07 | 2013-03-13 | 燕山大学 | Novel voltage type multi-level inverter |
| CN112953172A (en) * | 2021-01-28 | 2021-06-11 | 东南大学 | Method for modeling sequence impedance of modular multilevel converter under phase-locked loop coupling |
| CN114908356A (en) * | 2021-02-09 | 2022-08-16 | 江苏和网源电气有限公司 | Renewable energy source water electrolysis hydrogen production control system |
| CN114481215A (en) * | 2022-01-10 | 2022-05-13 | 清华大学 | Electrolytic hydrogen production device and control method thereof |
| CN116896272A (en) * | 2023-06-07 | 2023-10-17 | 北方工业大学 | Control method and device for new energy water electrolysis hydrogen production power supply |
Non-Patent Citations (2)
| Title |
|---|
| ZONGGEN YI等: "Deep reinforcement learnig based optmization for a tightly coupled nuclear reneable integrated energy system", 《ELSEVIER》, vol. 328, 15 December 2022 (2022-12-15), pages 1 - 33 * |
| 郭小强等: "新能源制氢电力电子变换器综述", 《电力系统自动化》, vol. 45, no. 20, 12 April 2021 (2021-04-12), pages 185 - 199 * |
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