CN110323763B - Inverter frequency modulation method integrating rotation inertia simulation and primary frequency modulation control - Google Patents
Inverter frequency modulation method integrating rotation inertia simulation and primary frequency modulation control Download PDFInfo
- Publication number
- CN110323763B CN110323763B CN201910648874.0A CN201910648874A CN110323763B CN 110323763 B CN110323763 B CN 110323763B CN 201910648874 A CN201910648874 A CN 201910648874A CN 110323763 B CN110323763 B CN 110323763B
- Authority
- CN
- China
- Prior art keywords
- inverter
- power supply
- frequency modulation
- frequency
- power
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- 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
-
- 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
- H02J2203/00—Indexing scheme relating to details of circuit arrangements for AC mains or AC distribution networks
- H02J2203/20—Simulating, e g planning, reliability check, modelling or computer assisted design [CAD]
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Inverter Devices (AREA)
- Control Of Eletrric Generators (AREA)
Abstract
The invention discloses an inverter frequency modulation method integrating rotational inertia simulation and primary frequency modulation control, wherein the primary frequency modulation detects the real-time frequency of an inverter power supply through a phase-locked loop, correspondingly changes the output of a generator set according to the detected frequency variation of the inverter power supply and the set difference modulation coefficient of the generator set, controls the frequency of the inverter power supply and the voltage of the inverter power supply by adjusting active power and reactive power, and belongs to droop control; the simulation of the rotational inertia is to calculate the electromagnetic power of the inverter power supply in real time as the feedback quantity of control and calculate the frequency variation quantity of the corresponding inverter power supply by utilizing a rotor motion equation, thereby realizing the rapid sampling of the internal frequency of the inverter power supply; therefore, the simulation of the rotational inertia is to control the output frequency of the inverter power supply through the energy change in the inverter power supply system, and is essentially the control of the falling.
Description
Technical Field
The invention relates to an inverter frequency modulation method integrating rotation inertia simulation and primary frequency modulation control, and belongs to the technical field of primary frequency modulation control of inverters.
Background
With the increasing severity of the problems caused by the consumption of traditional fossil energy, renewable energy power generation and grid connection technologies are widely concerned at home and abroad, and the actual grid connection capacity and proportion are higher and higher. The grid-connected inverter is used as an important device for connecting photovoltaic power generation and a large power grid, and has excellent performance in steady grid connection, but when a system is in transient conditions such as faults, the poor dynamic performance of the grid-connected inverter is not beneficial to the stability of the power grid. After a large-scale new energy is connected into a power grid in an isolated mode, the inertia of the whole system can be reduced due to the characteristics of the new energy, and therefore the actual frequency modulation capacity of the system is insufficient. When large-amplitude disturbance occurs due to sudden accidents in the system, the stability of the system frequency is often difficult to guarantee, so that the research on the photovoltaic inverter power supply comprehensive control system considering equivalent rotational inertia and primary frequency modulation is carried out, and the theoretical research significance and the engineering application value are achieved.
The patent provides an inverter frequency modulation method integrating rotation inertia simulation and primary frequency modulation control for primary frequency modulation of an inverter power supply. Under the control of the inverter power supply, when the system generates small disturbance within the dead zone, the system is supported only by the equivalent rotation inertia, and when the system generates large disturbance outside the dead zone, the equivalent rotation inertia and the primary frequency modulation control both play roles.
Disclosure of Invention
The inverter frequency modulation method for the comprehensive rotation inertia simulation and primary frequency modulation control is capable of enabling an inverter power supply to accurately and not excessively perform primary frequency modulation tracking control, approaching the mechanical inertia of a synchronous generator and achieving a grid-connected friendly condition.
In order to achieve the aim, the invention provides an inverter frequency modulation method integrating rotational inertia simulation and primary frequency modulation control, wherein the primary frequency modulation detects the real-time frequency of an inverter power supply through a phase-locked loop, correspondingly changes the output of a generator set according to the detected frequency variation of the inverter power supply and the set difference modulation coefficient of the generator set, controls the frequency of the inverter power supply and the voltage of the inverter power supply by adjusting active power and reactive power, and belongs to droop control; the simulation of the rotational inertia is to calculate the electromagnetic power of the inverter power supply in real time as the feedback quantity of control and calculate the frequency variation quantity of the corresponding inverter power supply by utilizing a rotor motion equation, thereby realizing the rapid sampling of the internal frequency of the inverter power supply; therefore, the simulation of the rotational inertia is to control the output frequency of the inverter power supply through the energy change in the inverter power supply system, and is essentially the control of the falling.
Preferentially, the simulation of the rotation inertia and the control of the primary frequency modulation are coordinated by setting a primary frequency modulation dead zone; when the frequency change of the inverter power supply is in the set primary frequency modulation dead zone after small disturbance occurs, only a rotation inertia link acts at the moment; when the frequency change of the inverter power supply exceeds the set primary frequency modulation dead zone after large disturbance occurs, the inverter power supply is mainly controlled by primary frequency modulation; the simulation link of the rotational inertia responds inside and outside the primary frequency modulation control dead zone and is irrelevant to the action of the primary frequency modulation control link;
preferably, the method comprises the following steps:
firstly, when a system is disturbed, a rotating inertia simulation link starts to act, firstly, voltage and current signals of PCC (point of common coupling) are collected in real time at a high speed, and real-time electromagnetic power P of a three-phase power supply is calculated in real time k ：
P k ＝u a i a +u b i b +u c i c ，
Wherein u is a 、u b 、u c Voltages of three-phase power supplies, i a 、i b And i c Are each u a 、u b 、u c (ii) a A corresponding current; thereby obtaining real-time electromagnetic power P k Then the real-time electromagnetic power P obtained by the preliminary calculation is used k Obtaining stable output real-time stable electromagnetic power P through low-pass filter k * ；
Considering the actually measured electromagnetic power P of a three-phase power supply e Has random fluctuation, and n real-time stable electromagnetic powers P before the moment are calculated in real time in order to inhibit the influence of the random fluctuation k * Obtain the average value P of power ave As a digital filter, averaging the power P ave And real-time stabilization of the electromagnetic power P k * Calculating difference to obtain Δ P e (ii) a Wherein the electromagnetic power P is stabilized in real time k * And the average value P of the first n powers ave The calculation formula of (a) is as follows:
step two, according to the small signal model under the per unit value of the rotor motion equation, defining the deviation amount of the electromagnetic power in the rotor motion equation as:
ΔP e ＝-(P k ＊ -P ave )
when Δ Pe is less than 0, the energy storage element inside the inverter absorbs excess energy, which is accompanied by an increase in frequency; when Δ Pe >0, the energy storage element inside the inverter should release the stored energy.
Preferentially, the internal frequency characteristic of the inverter power supply is considered in the simulation of the rotation inertia and the control of the primary frequency modulation, the rotor motion equation is used, and the relevance of a control strategy is enhanced; the difference between the simulation of the rotational inertia and the control of the primary frequency modulation is that the rotor motion equation in the control of the primary frequency modulation performs the frequency control of the power-frequency response; in the simulation of the rotation inertia, the rotor motion equation is used for realizing the rapid sampling of the internal frequency of the inverter power supply and carrying out the deviation control of the angular frequency by the rapid change of the internal energy storage of the inverter.
Preferably, the second step further comprises the steps of: in order to reduce the complexity of the model, the controller selects a second-order model of the synchronous generator:
j is mechanical moment of inertia, T m Is the mechanical torque of the prime mover, T e Is the electromagnetic torque of the generator, omega is the actual angular velocity, t is the time, P T Is the mechanical power of the generator, P e For electromagnetic power of generators, ω n Is a rated rotating speed;
during primary frequency modulation, establishing a primary frequency modulation droop controller model of the inverter:
P T ＝P ref +(f-f ref )/δ
in the formula, P ref Is given a reference mechanical power, f is the real-time frequency, f ref A given reference frequency is adopted, and delta refers to a difference adjustment coefficient of the generator set; when the power supply system of the inverter is stable, the difference value is 0, and when disturbance occurs on the network side, the delta P is e Not equal to 0; taking into account the electromagnetic power P e Negative coefficient terms in the equation of motion of the rotor, and thus taken before the amount of deviationAnd (5) minus sign, establishing a small signal model under a per unit value of a rotor motion equation:
ΔP e ＝-(P k ＊ -P ave )，
in the formula, Δ Pe refers to the deviation of the electromagnetic power in the rotor motion equation; p k Refers to real-time electromagnetic power; p ave Means the average power value; Δ Pm refers to the amount of change in mechanical power; Δ ω' is the internal angular frequency variation; when the rotational inertia is simulated, the delta P is calculated e Sending the angular frequency variation delta omega 'into a rotor motion equation to realize the calculation of the internal angular frequency variation delta omega'; wherein P is ave Equivalent to electromagnetic power, and after linearization near the stable operating point during small perturbations, consider Δ P m The corresponding internal rotational speed/angular frequency change can then be calculated from the above equation.
Preferably, the second step further comprises the steps of: when the inverter power supply system is disturbed, the phase-locked loop starts to detect the real-time frequency of the inverter power supply, the difference is made between the acquired real-time frequency f of the inverter power supply and the rated frequency fn, and the absolute value is compared with the dead zone threshold value; and when the absolute value of the delta f is larger than the dead zone threshold, the primary frequency modulation control link starts to act to calculate the external angular frequency variation delta omega.
Preferably, in step three, the internal angular frequency change amount Δ ω' and the external angular frequency change amount Δ ω in step two are used as phase commands of the inverter power supply output voltage, and the phase commands are used for coordinate conversion of the inner ring.
Preferentially, the step four: comprehensively considering a power grid voltage feedforward term and a current feedback term to obtain a d-axis component U of a reference voltage of an expected output grid-connected point md And q-axis component U mq And combining the phase instruction to realize inverse Park conversion from dq coordinates to abc coordinates, and then sending the converted data to PWM to generate a control signal.
Preferentially, the step five: and correcting the ratio of the deviation delta Pe of the electromagnetic power in the rotor motion equation in the step two to the initial power of the inverter to serve as correction of the voltage signal in the step four.
Preferentially, step six: and correspondingly, the active increment is obtained through calculation according to the frequency variation delta f and the adjustment coefficient delta of the inverter power supply, at the moment, the reference value Pref of the photovoltaic output power is changed, and the power tracking point is adjusted through non-MPPT control, namely, the output power is increased or reduced so as to participate in the control of primary frequency modulation.
The invention achieves the following beneficial effects:
according to the inverter power supply capable of comprehensively simulating rotation inertia and controlling primary frequency modulation, when small disturbance occurs in a primary frequency modulation control dead zone, the inertia effect similar to that of a synchronous generator is realized through the change of stored energy, and the inverter only performs internal control when the rotation inertia is simulated; and when the dead zone range of the primary frequency modulation is exceeded, correspondingly changing the output according to the detected frequency variation and the set difference modulation coefficient, thereby carrying out primary frequency modulation control. Therefore, the inverter power supply prevents jitter or excessive tracking control, so that the control of the system is more accurate and is more friendly to grid connection.
Drawings
FIG. 1 is a functional block diagram of the present invention;
fig. 2 is a control block diagram of the present invention.
Detailed Description
The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.
Referring to fig. 1, the primary frequency modulation link is implemented by detecting a frequency through a PLL (phase locked loop), comparing the detected frequency with a rated value and then with a set dead zone, thereby determining whether to start a primary frequency modulation measure, and correspondingly changing a power according to a detected frequency variation and a set difference modulation coefficient, thereby adjusting the frequency; and the rotation inertia simulation link is based on the deviation of the load instantaneous power and the average power as the basis for energy conversion of the internal energy storage element: when the delta P is less than 0, the internal frequency is reduced, and at the moment, an energy storage element in the inverter power supply releases energy storage; when Δ P >0, the internal frequency rises. The two controls both use a rotor motion equation, and the relevance of control strategies is strengthened.
When the system generates load disturbance, the rotation inertia simulation link responds correspondingly no matter whether the primary frequency modulation control link acts or not, and the characteristic that the inverter power supply participates in power balance can be more accurately represented without completely depending on the control of collecting external frequency signals. When the frequency change after disturbance is in the set primary frequency modulation dead zone, only the rotating inertia link acts at the moment, and when the frequency change exceeds the set primary frequency modulation dead zone, the control is mainly carried out by means of primary frequency modulation.
A frequency modulation method of an inverter integrating rotational inertia simulation and primary frequency modulation control is characterized in that the primary frequency modulation detects the real-time frequency of an inverter power supply through a phase-locked loop, correspondingly changes the output of a generator set according to the detected frequency variation of the inverter power supply and the set difference modulation coefficient of the generator set, controls the frequency of the inverter power supply and the voltage of the inverter power supply by adjusting active power and reactive power, and belongs to droop control; the simulation of the rotational inertia is to calculate the electromagnetic power of the inverter power supply in real time as the feedback quantity of control and calculate the frequency variation quantity of the corresponding inverter power supply by utilizing a rotor motion equation, thereby realizing the rapid sampling of the internal frequency of the inverter power supply; therefore, the simulation of the rotational inertia is to control the output frequency of the inverter power supply through the energy change in the inverter power supply system, and is essentially the control of the falling.
Furthermore, the simulation of the rotation inertia and the control of primary frequency modulation are coordinated by setting a primary frequency modulation dead zone; when the frequency change of the inverter power supply is in the set primary frequency modulation dead zone after small disturbance occurs, only a rotation inertia link acts at the moment; when the frequency change of the inverter power supply exceeds the set primary frequency modulation dead zone after large disturbance occurs, the inverter power supply is mainly controlled by primary frequency modulation; the simulation link of the rotational inertia responds inside and outside the primary frequency modulation control dead zone and is irrelevant to the action of the primary frequency modulation control link;
further, the method comprises the following steps:
firstly, when a system is disturbed, a rotating inertia simulation link starts to act, firstly, voltage and current signals of PCC (point of common coupling) are collected in real time at a high speed, and real-time electromagnetic power P of a three-phase power supply is calculated in real time k ：
P k ＝u a i a +u b i b +u c i c ，
Wherein u is a 、u b 、u c Voltages of three-phase power supplies, i a 、i b And i c Are each u a 、u b 、u c (ii) a A corresponding current; thereby obtaining real-time electromagnetic power P k Then the real-time electromagnetic power P obtained by the preliminary calculation is used k Obtaining stable output real-time stable electromagnetic power P through low-pass filter k * ；
Considering the actually measured electromagnetic power P of a three-phase power supply e Has random fluctuation, and in order to inhibit the influence of the random fluctuation, n real-time stable electromagnetic powers P before the moment are calculated in real time k * Obtain the average value P of power ave As a digital filter, averaging the power P ave And real-time stabilization of the electromagnetic power P k * Calculating the difference to obtain Δ P e (ii) a Wherein the electromagnetic power P is stabilized in real time k * And the average value P of the first n powers ave The calculation formula of (a) is as follows:
Step two, according to the small signal model under the per unit value of the rotor motion equation, defining the deviation amount of the electromagnetic power in the rotor motion equation as:
ΔP e ＝-(P k ＊ -P ave )
when Δ Pe is less than 0, the energy storage element inside the inverter absorbs excess energy, which is accompanied by an increase in frequency; when Δ Pe >0, the energy storage element inside the inverter should release the stored energy.
Furthermore, the internal frequency characteristic of the inverter power supply is considered in the simulation of the rotation inertia and the control of the primary frequency modulation, the rotor motion equation is used, and the relevance of a control strategy is enhanced; the difference between the simulation of the rotational inertia and the control of the primary frequency modulation is that the rotor motion equation in the control of the primary frequency modulation performs the frequency control of the power-frequency response; in the simulation of the rotation inertia, the rotor motion equation is used for realizing the rapid sampling of the internal frequency of the inverter power supply and carrying out the deviation control of the angular frequency by the rapid change of the internal energy storage of the inverter.
Further, the second step further comprises the following steps: in order to reduce the complexity of the model, the controller selects a second-order model of the synchronous generator:
j is mechanical moment of inertia, T m Is the mechanical torque of the prime mover, T e Is the electromagnetic torque of the generator, omega is the actual angular velocity, t is the time, P T Is the mechanical power of the generator, P e Being electromagnetic power of the generator, omega n Is a rated rotating speed;
during primary frequency modulation, establishing a primary frequency modulation droop controller model of the inverter:
P T ＝P ref +(f-f ref )/δ
in the formula, P ref Is given a reference mechanical power, f is the real-time frequency, f ref A given reference frequency is adopted, and delta refers to a difference adjustment coefficient of the generator set; when the power supply system of the inverter is stable, the difference value is 0, and when disturbance occurs on the network side, the delta P is e Not equal to 0; taking into account the electromagnetic power P e And a negative coefficient term is used in the rotor motion equation, so that a negative sign is taken before the deviation value, and a small signal model under the per unit value of the rotor motion equation is established:
ΔP e ＝-(P k ＊ -P ave )，
in the formula, Δ Pe refers to the deviation of the electromagnetic power in the rotor motion equation; p is k Refers to real-time electromagnetic power; p ave Means the average power value; Δ Pm refers to the amount of change in mechanical power; Δ ω' is the internal angular frequency variation; when the rotational inertia is simulated, the delta P is calculated e Sending the angular frequency variation delta omega 'into a rotor motion equation to realize the calculation of the internal angular frequency variation delta omega'; wherein P is ave Equivalent to electromagnetic power, and after linearization near the stable operating point during small perturbations, consider Δ P m The corresponding internal rotational speed/angular frequency change can then be calculated from the above equation.
Further, the second step further comprises the following steps: when the inverter power supply system is disturbed, the phase-locked loop starts to detect the real-time frequency of the inverter power supply, the difference is made between the acquired real-time frequency f of the inverter power supply and the rated frequency fn, and the absolute value is compared with the dead zone threshold value; and when the absolute value of the delta f is larger than the dead zone threshold, the primary frequency modulation control link starts to act to calculate the external angular frequency variation delta omega.
Further, in step three, the internal angular frequency change amount Δ ω' and the external angular frequency change amount Δ ω in step two are used as phase commands of the inverter power supply output voltage, and the phase commands are used for coordinate conversion of the inner ring.
Further, step four: comprehensively considering a power grid voltage feedforward term and a current feedback term to obtain a d-axis component U of a reference voltage of an expected output grid-connected point md And q-axis component U mq And combining the phase instruction to realize inverse Park conversion from dq coordinates to abc coordinates, and then sending the converted data to PWM to generate a control signal.
Further, step five: and correcting the ratio of the deviation delta Pe of the electromagnetic power in the rotor motion equation in the step two to the initial power of the inverter to serve as correction of the voltage signal in the step four.
Further, step six: and correspondingly, the active increment is obtained through calculation according to the frequency variation delta f and the adjustment coefficient delta of the inverter power supply, at the moment, the reference value Pref of the photovoltaic output power is changed, and the power tracking point is adjusted through non-MPPT control, namely, the output power is increased or reduced so as to participate in the control of primary frequency modulation.
And in the simulation link of the rotation inertia, the internal angular frequency is quickly estimated through a rotor motion equation and is used as a phase command of the output voltage of the inverter, and the command is used for the coordinate transformation of the inner ring. In addition, the power deviation amount delta P can be obtained after the difference is made between the current time power and the average power, and the ratio of the power deviation amount delta P to the initial power is corrected to serve as the correction of the voltage signal.
The port frequency of the system is the result of the combined action of the internal frequency and the external frequency, and the requirement of droop consistency is lowered; the external frequency refers to that the primary frequency modulation control link detects the frequency through a phase-locked loop, and carries out droop control to change the output according to the detected frequency variation, so as to adjust the frequency; the internal frequency refers to that the analog link of the rotational inertia is the basis for energy conversion of an internal energy storage element according to the deviation amount of the load instantaneous power and the average power, when the delta P is less than 0, the internal frequency is reduced, and at the moment, the energy storage element in the inverter power supply releases energy storage; when Δ P >0, the internal frequency rises.
ΔP e ＝-(P k -P ave ) With minus brackets is the amount of deviation of the electromagnetic power in the rotor equation of motion and is therefore a per unit state.
The dead zone threshold value is defined as a value serving as a dead zone critical value, namely the critical value, and the difference adjustment coefficient delta is the difference adjustment coefficient delta of the (new energy) generator set.
The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.
Claims (4)
1. The inverter frequency modulation method is characterized in that the primary frequency modulation detects the real-time frequency of an inverter power supply through a phase-locked loop, correspondingly changes the output of a generator set according to the detected frequency variation of the inverter power supply and the set difference coefficient of the generator set, controls the frequency of the inverter power supply and the voltage of the inverter power supply by adjusting active power and reactive power, and belongs to droop control; the simulation of the rotational inertia is to calculate the electromagnetic power of the inverter power supply in real time as the feedback quantity of control and calculate the frequency variation quantity of the corresponding inverter power supply by utilizing a rotor motion equation, thereby realizing the rapid sampling of the internal frequency of the inverter power supply; therefore, the simulation of the rotation inertia is to control the output frequency of the inverter power supply through the energy change in the inverter power supply system, and essentially belongs to the falling control;
when small disturbance occurs in the primary frequency modulation control dead zone, the inertia effect similar to that of a synchronous generator is realized through the change of stored energy, and the inverter only performs internal control when simulating the rotation inertia; when the frequency exceeds the dead zone range of primary frequency modulation, correspondingly changing the output according to the detected frequency variation and the set difference modulation coefficient, thereby carrying out primary frequency modulation control;
the simulation of the rotation inertia and the control of primary frequency modulation are coordinated by setting a primary frequency modulation dead zone; when the frequency change of the inverter power supply is in the set primary frequency modulation dead zone after small disturbance occurs, only a rotation inertia link acts at the moment; when the frequency change of the inverter power supply exceeds the set primary frequency modulation dead zone after large disturbance occurs, the inverter power supply is mainly controlled by primary frequency modulation; the simulation link of the rotational inertia responds inside and outside the primary frequency modulation control dead zone and is irrelevant to the action of the primary frequency modulation control link;
firstly, when a system is disturbed, a rotating inertia simulation link starts to act, firstly, voltage and current signals of PCC (point-to-point control) of a grid-connected point are acquired in real time at a high speed, and real-time electromagnetic power P of a three-phase power supply is calculated in real time k ：
P k ＝u a i a +u b i b +u c i c ，
Wherein u is a 、u b 、u c Voltages of three-phase power supplies, i a 、i b And i c Are each u a 、u b 、u c A corresponding current; thereby obtaining real-time electromagnetic power P k Then the real-time electromagnetic power P obtained by the preliminary calculation is used k Obtaining stable output real-time stable electromagnetic power P through low-pass filter k * ；
Considering the actually measured electromagnetic power P of a three-phase power supply e Has random fluctuation, and in order to inhibit the influence of the random fluctuation, n real-time stable electromagnetic powers P before the moment are calculated in real time k * Obtain the average value P of power ave As a digital filter, averaging the power P ave And real-time stabilization of the electromagnetic power P k * Calculating the difference to obtain Δ P e (ii) a Wherein the first n power average values P ave The calculation formula of (a) is as follows:
step two, according to the small signal model under the per unit value of the rotor motion equation, defining the deviation amount of the electromagnetic power in the rotor motion equation as follows:
when Δ Pe is less than 0, the energy storage element inside the inverter absorbs excess energy, which is accompanied by an increase in frequency; when Δ Pe >0, the energy storage element inside the inverter should release the stored energy;
the second step also comprises the following steps: in order to reduce the complexity of the model, the controller selects a second-order model of the synchronous generator:
j is mechanical moment of inertia, T m Is the mechanical torque of the prime mover, T e Is the electromagnetic torque of the generator, omega is the actual angular velocity, t is the time, P T Is the mechanical power of the generator, P e Being electromagnetic power of the generator, omega n Is a rated rotating speed;
during primary frequency modulation, establishing a primary frequency modulation droop controller model of the inverter:
P T ＝P ref +(f-f ref )/δ
in the formula, P ref Means that a reference mechanical power is given, f means a real-time frequency, f ref A given reference frequency is adopted, and delta refers to a difference adjustment coefficient of the generator set; when the power supply system of the inverter is stable, the difference value is 0, and when disturbance occurs on the network side, the delta P is e Not equal to 0; taking into account the electromagnetic power P e And a negative coefficient term is used in the rotor motion equation, so that a negative sign is taken before the deviation value, and a small signal model under the per unit value of the rotor motion equation is established:
in the formula, Δ Pe refers to the deviation of the electromagnetic power in the rotor motion equation; p k Refers to real-time electromagnetic power; p ave Means the average power value; Δ Pm refers to the amount of change in mechanical power; Δ ω' is the internal angular frequency variation; when the rotational inertia is simulated, the delta P is calculated e Sending the angular frequency variable quantity delta omega 'into a rotor motion equation to realize the calculation of the internal angular frequency variable quantity delta omega'; wherein P is ave Equivalent to electromagnetic power, and after linearization near the stable operating point during small perturbations, consider Δ P m When the rotational speed is 0, the corresponding internal rotational speed/angular frequency can be calculated according to the above formula(ii) a change;
the second step also comprises the following steps: when the inverter power supply system is disturbed, the phase-locked loop starts to detect the real-time frequency of the inverter power supply, the difference is made between the acquired real-time frequency f of the inverter power supply and the rated frequency fn, and the absolute value is compared with the dead zone threshold value; when the absolute value of delta f is larger than the dead zone threshold, the primary frequency modulation control link starts to act, and the external angular frequency variation delta omega is calculated;
and step three, taking the internal angular frequency change amount delta omega' and the external angular frequency change amount delta omega in the step two as phase commands of the output voltage of the inverter power supply, wherein the phase commands are used for the coordinate transformation of the inner ring.
2. The inverter frequency modulation method integrating the rotation inertia simulation and the primary frequency modulation control as claimed in claim 1, wherein the step four: comprehensively considering a power grid voltage feedforward term and a current feedback term to obtain a d-axis component U of a reference voltage of an expected output grid-connected point md And q-axis component U mq And combining the phase instruction to realize inverse Park conversion from dq coordinates to abc coordinates, and then sending the converted data to PWM to generate a control signal.
3. The inverter frequency modulation method integrating the rotation inertia simulation and the primary frequency modulation control as claimed in claim 1, wherein the step five: and correcting the ratio of the deviation delta Pe of the electromagnetic power in the rotor motion equation in the step two to the initial power of the inverter to serve as correction of the voltage signal in the step four.
4. The inverter frequency modulation method integrating the rotation inertia simulation and the primary frequency modulation control as claimed in claim 1, wherein the step six: calculating according to the frequency variation delta f and the difference adjustment coefficient delta of the inverter power supply to obtain corresponding active increment, wherein the reference value of the photovoltaic output power at the moment is as follows: giving a reference mechanical power P ref And changing to adjust the power tracking point through non-MPPT control, namely increasing or reducing the output power so as to participate in the control of primary frequency modulation.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910648874.0A CN110323763B (en) | 2019-07-18 | 2019-07-18 | Inverter frequency modulation method integrating rotation inertia simulation and primary frequency modulation control |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910648874.0A CN110323763B (en) | 2019-07-18 | 2019-07-18 | Inverter frequency modulation method integrating rotation inertia simulation and primary frequency modulation control |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110323763A CN110323763A (en) | 2019-10-11 |
| CN110323763B true CN110323763B (en) | 2022-09-16 |
Family
ID=68123908
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910648874.0A Active CN110323763B (en) | 2019-07-18 | 2019-07-18 | Inverter frequency modulation method integrating rotation inertia simulation and primary frequency modulation control |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110323763B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112421658B (en) * | 2020-10-20 | 2022-09-09 | 浙江大学 | Inertia link control method of energy storage inverter in emergency microgrid scene |
| CN113162122B (en) * | 2021-02-26 | 2022-08-02 | 华中科技大学 | Virtual synchronous machine control method and system based on consistency algorithm |
| US11715958B2 (en) * | 2021-07-29 | 2023-08-01 | General Electric Company | System and method for power control of an inverter-based resource with a grid-forming converter |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106684921A (en) * | 2017-03-20 | 2017-05-17 | 重庆大学 | Inverter secondary-frequency-regulation control circuit based on virtual synchronous generator |
| CN107482939A (en) * | 2017-09-08 | 2017-12-15 | 中南大学 | A kind of inverter control method |
| CN109672190A (en) * | 2019-01-15 | 2019-04-23 | 燕山大学 | A kind of control method and system of wind-electricity integration inverter frequency modulation |
-
2019
- 2019-07-18 CN CN201910648874.0A patent/CN110323763B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106684921A (en) * | 2017-03-20 | 2017-05-17 | 重庆大学 | Inverter secondary-frequency-regulation control circuit based on virtual synchronous generator |
| CN107482939A (en) * | 2017-09-08 | 2017-12-15 | 中南大学 | A kind of inverter control method |
| CN109672190A (en) * | 2019-01-15 | 2019-04-23 | 燕山大学 | A kind of control method and system of wind-electricity integration inverter frequency modulation |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110323763A (en) | 2019-10-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110970933B (en) | Active support control-based virtual inertia compensation method for light-storage combined power generation system | |
| CN111146809B (en) | Grid-connected inverter transient stability control method based on improved phase-locked loop | |
| CN110323763B (en) | Inverter frequency modulation method integrating rotation inertia simulation and primary frequency modulation control | |
| CN105790297B (en) | The inertia control method and device of total power wind-driven generator based on built-in potential response | |
| CN110912158A (en) | Multi-terminal flexible direct-current power transmission system frequency stability control method with wind power participating in frequency modulation | |
| CN112217235A (en) | Voltage source type full-power wind turbine generator control method based on energy storage coordination control | |
| CN108462203B (en) | Cooperative control method for accessing offshore wind farm to conventional high-voltage direct-current system | |
| WO2022198764A1 (en) | Control method and system for offshore wind power grid-connected system | |
| CN111162560B (en) | Method for improving active support control fault ride-through capability based on virtual impedance FCL | |
| CN112350381B (en) | Time-sharing coordination control method and system during MPPT operation of PMSG fan | |
| WO2023077740A1 (en) | Direct-current capacitor synchronous control system for grid-connected converter, and control method | |
| CN110350551B (en) | Direct current amplitude-frequency control method and system for voltage source type grid-connected conversion device | |
| CN113193605B (en) | Active power direct control method of voltage control type new energy converter | |
| CN110829461A (en) | Inverter controller with function of participating in system low-frequency oscillation suppression | |
| CN113346562A (en) | Control method for low voltage ride through of permanent magnet direct drive type wind turbine generator | |
| Dey et al. | A coordinated control of grid connected PMSG based wind energy conversion system under grid faults | |
| CN110460113B (en) | Mechanical inertia simulation method of inverter power supply | |
| CN114243787B (en) | Control method and system for improving transient synchronization stability of wind power grid-connected system | |
| CN113852099B (en) | Rapid frequency response control system and method for direct-driven wind turbine generator | |
| CN115579966A (en) | Network-building type doubly-fed wind turbine generator control method based on hybrid synchronization | |
| CN115065068A (en) | Virtual synchronous machine control method for photovoltaic system without energy storage configuration at source end | |
| CN114421498A (en) | Medium-voltage wind power system fluctuation power stabilizing method and system based on energy router | |
| Liu et al. | Adaptive Virtual Impedance Current Limiting Strategy for Grid-Forming Converter | |
| CN110829483B (en) | Phase-shifting phase-locked loop method based on back electromotive force observer | |
| CN110661281A (en) | Coordination control method and system for light-storage integrated virtual synchronous generator |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |