Photovoltaic station transient voltage active suppression method based on droop control

Abstract

The invention discloses a droop control-based active transient voltage suppression method for a photovoltaic station, and relates to the field of active support capability control of new energy transient voltage, and the method comprises the steps: constructing a photovoltaic station overall model, and making a corresponding droop control strategy; according to a droop control strategy, operating the overall model of the photovoltaic station, and obtaining a corresponding reactive power parameter; based on the reactive power parameters and the overall model of the photovoltaic station, constructing a reactive power control model of the photovoltaic station; calculating a droop control coefficient based on the reactive power control model; and updating and operating the droop control strategy, and suppressing the transient voltage of the photovoltaic station. According to the method, when transient voltage fluctuation occurs in the direct-current power transmission system, by controlling active and reactive output of the power supply, frequency and voltage stability is achieved respectively, a droop control coefficient is calculated, the problem of unbalanced power distribution between inverters is prevented, transient fluctuation of a photovoltaic field station is effectively suppressed, and the stability of the direct-current power transmission system is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of active support capability control of renewable energy transient voltage, and in particular to a method for actively suppressing transient voltage in a photovoltaic station based on droop control. Background Art

[0002] The distribution characteristics of my country's new energy and electricity load are inversely distributed, with wind and photovoltaic power generation resources mainly concentrated in the northwest, and electricity load concentrated in the southeast. Since the two places are relatively far apart, in order to improve transmission efficiency and reduce losses during transmission, we usually use the method of increasing voltage for long-distance transmission. Through technologies such as ultra-high voltage direct current transmission, we can effectively achieve long-distance, large-capacity power transmission to meet the power demand between energy bases and load centers.

[0003] During operation, the DC transmission system may be affected by various factors and generate transient overvoltage. Transient overvoltage will not only damage the system equipment and reduce the service life of the equipment, but may also cause the system protection device to malfunction, resulting in serious consequences such as system power outages. Therefore, how to effectively suppress transient overvoltage in the DC transmission system has become an important issue that needs to be solved in the current field of renewable energy power generation and power grid operation. Summary of the invention

[0004] The object of the present invention is to provide a method for actively suppressing transient voltage in a photovoltaic station based on droop control, so as to improve the above technical problems.

[0005] In order to achieve the above-mentioned object of the invention, the embodiment of the present invention provides the following technical solutions:

[0006] A method for actively suppressing transient voltage in a photovoltaic station based on droop control, comprising:

[0007] Constructing a photovoltaic station overall model and formulating a droop control strategy for the photovoltaic station overall model;

[0008] According to the droop control strategy, the photovoltaic station overall model is run to obtain corresponding active and reactive power parameters;

[0009] Based on the active and reactive power parameters and the overall model of the photovoltaic station, a reactive power control model of the photovoltaic station is constructed;

[0010] Calculating a droop control coefficient based on the photovoltaic station reactive power control model;

[0011] Based on the droop control coefficient, the droop control strategy is updated; and the updated droop control strategy is run to suppress the transient voltage of the photovoltaic station.

[0012] Furthermore, the overall model of the photovoltaic station includes a station-level control model, a voltage ride-through state judgment module, a photovoltaic array model, a control module and a converter model; wherein:

[0013] Station-level control model, used to obtain station-level active power control instructions , Station-level reactive power control instructions , and input to the control module;

[0014] The voltage ride-through state judgment module is used to determine the voltage amplitude at the machine end. , Reactive power at the machine end , Machine-side active power Determine the voltage ride-through state of the overall model of the photovoltaic station and obtain the corresponding voltage ride-through state , and input to the control module;

[0015] Photovoltaic array model, used to calculate the , get the output power of the photovoltaic array , and input to the control module;

[0016] A control module is used to control the reactive power according to the station level reactive power control instruction. , Station-level active power control instructions , terminal voltage amplitude , Reactive power at the machine end , Machine-side active power , Voltage Ride-Through State , PV array output power , determine the control strategy of the overall model of the photovoltaic station, and output the active current control instruction , reactive current control command To the converter model; wherein the control strategy includes normal operation control, voltage ride-through control and current ride-through control.

[0017] A converter model for inputting active current control instructions according to the control strategy , reactive current control command , the output is the reactive current component , active current component .

[0018] Furthermore, the formula of the photovoltaic array model is:

[0019]

[0020] in, , , They represent the ambient temperature, ambient temperature difference and ambient temperature reference value of the photovoltaic station respectively. , , Respectively represent light intensity, light intensity difference, and light intensity reference value. , Represent the photovoltaic array model The short-circuit current and the corrected short-circuit current, , , represents the correction factor, , Represent the photovoltaic array model The open circuit current and the corrected open circuit current, , Represent the photovoltaic array model The maximum power point voltage and the revised maximum power point voltage, Indicated by natural constant The logarithmic function with base .

[0021] Furthermore, the photovoltaic station overall model is run according to the droop control strategy to obtain corresponding active and reactive power parameters, including:

[0022] The active power provided by the photovoltaic station in the overall photovoltaic station model , reactive power provided by photovoltaic stations ,Voltage ,frequency , Photovoltaic station active power set value , Photovoltaic station reactive power set value , PV station voltage set value Input to the station-level control model, and output the station-level active power control instruction , Station-level reactive power control instructions ;

[0023] The terminal voltage amplitude in the overall model of the photovoltaic station is , Reactive power at the machine end , Machine-side active power Input to the voltage ride-through state judgment module, and output the corresponding voltage ride-through state ;

[0024] The light intensity in the overall model of the photovoltaic station Input to the photovoltaic array model, and output the photovoltaic array output power ;

[0025] The station-level active power control instruction , the station-level reactive power control instruction , the photovoltaic array outputs active power , Voltage Ride-Through State Input to the converter model, and output the reactive current component , active current component , that is, active and reactive power parameters.

[0026] Furthermore, based on the active and reactive power parameters and the overall model of the photovoltaic station, a photovoltaic station reactive power control model is constructed, and the specific process is as follows:

[0027] Based on the active and reactive power parameters, the station-level control model and the converter model, a photovoltaic station reactive power control model is constructed; the photovoltaic station reactive power control model includes a photovoltaic station-level reactive power control model and a photovoltaic converter-level reactive power control model.

[0028] Furthermore, the formula of the photovoltaic station-level reactive power control model is:

[0029]

[0030] in, represents the differential operator in the complex frequency domain, Represents the reactive power output by reactive PI control, , Indicates the leading and lagging time constant of reactive power command, Indicates the time constant of the measurement filter link, , , They represent the proportional, integral and reactive droop coefficients of the PI controller of the converter model respectively. , Represent voltage deviation and reference voltage respectively.

[0031] Furthermore, the formula of the reactive power control model of the photovoltaic converter stage is:

[0032]

[0033] in, , They represent the reactive current control command and reactive current injection amount of the converter station respectively. , , Respectively represent reactive power reference value, station-level reactive power control instruction, and reactive power actual value. Indicates the station-level reactive power control instruction.

[0034] Furthermore, the droop control coefficient is calculated based on the photovoltaic station reactive power control model, including:

[0035] Running the photovoltaic station-level reactive power control model and the photovoltaic converter-level reactive power control model to obtain corresponding electrical quantities;

[0036] The droop control coefficient is calculated based on the electrical quantity, and the calculation formula is:

[0037]

[0038] in, , They represent the active power droop coefficient and reactive power droop coefficient respectively. , , , They respectively represent the rated angular frequency, rated active power, rated converter output voltage, and rated reactive power.

[0039] The present invention can achieve frequency and voltage stability by controlling the active and reactive outputs of the power supply respectively when transient voltage fluctuations occur in the DC transmission system, calculate the corresponding droop control coefficient, effectively distribute the power of the photovoltaic station, prevent the problem of unbalanced power distribution between inverters, effectively suppress the transient fluctuations of the photovoltaic station, and actively improve the stability of the DC transmission system. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0041] Figure 1 is a flow chart of the invention in an embodiment of the present invention;

[0042] Figure 2 Schematic diagram of the overall model structure of a photovoltaic station in an embodiment of the present invention;

[0043] Figure 3 is a droop characteristic curve diagram in an embodiment of the present invention;

[0044] Figure 4 is a control diagram of a photovoltaic station-level reactive power control model in an embodiment of the present invention;

[0045] Figure 5 is a control diagram of a reactive power control model of a photovoltaic converter stage in an embodiment of the present invention;

[0046] Figure 6 is a transient voltage curve diagram of the photovoltaic side machine end when no control strategy is adopted after DC blocking occurs in an embodiment of the present invention;

[0047] Figure 7 This is a transient voltage curve diagram of the photovoltaic side machine end after droop control is adopted in an embodiment of the present invention. DETAILED DESCRIPTION

[0048] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents the selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present invention.

[0049] See also Figure 1 This embodiment provides a method for actively suppressing transient voltage in a photovoltaic station based on droop control, which includes:

[0050] Constructing a photovoltaic station overall model and formulating a droop control strategy for the photovoltaic station overall model;

[0051] like Figure 2 As shown, the overall model of the photovoltaic station includes a station-level control model, a voltage ride-through state judgment module, a photovoltaic array model, a control module and a converter model; wherein:

[0052] Station-level control model, used to obtain station-level active power control instructions , Station-level reactive power control instructions , and input to the control module;

[0053] The voltage ride-through state judgment module is used to determine the voltage amplitude at the machine end. , Reactive power at the machine end , Machine-side active power Determine the voltage ride-through state of the overall model of the photovoltaic station and obtain the corresponding voltage ride-through state , and input to the control module;

[0054] Photovoltaic array model, used to calculate the , get the output power of the photovoltaic array , and input to the control module;

[0055] A control module is used to control the reactive power according to the station level reactive power control instruction. , Station-level active power control instructions , terminal voltage amplitude , Reactive power at the machine end , Machine-side active power , Voltage Ride-Through State , PV array output power , determine the control strategy of the overall model of the photovoltaic station, and output the active current control instruction , reactive current control command To the converter model; wherein the control strategy includes normal operation control, voltage ride-through control and current ride-through control.

[0056] A converter model for inputting active current control instructions according to the control strategy , reactive current control command , the output is the reactive current component , active power component .

[0057] like Figure 3 As shown, by simulating the droop characteristics of traditional generators as a control method, the photovoltaic station is controlled by controlling the active output and reactive output of the control power supply of the photovoltaic station to achieve frequency and voltage stability, that is, to formulate a droop control strategy for the overall model of the photovoltaic station. The calculation formula for frequency and voltage is:

[0058]

[0059] in, , They represent the actual frequency value and rated frequency value of the overall model of the photovoltaic station, , They represent the actual voltage value and rated voltage value of the overall model of the photovoltaic station, , They represent the active power droop coefficient and reactive power droop coefficient of the overall model of the photovoltaic station, , They represent the active power and reactive power of the overall model of the photovoltaic station respectively.

[0060] The photovoltaic array model simulates the current generated by photovoltaic cells under certain temperature and light intensity conditions, so the corresponding model formula is:

[0061]

[0062] Because the light intensity and temperature are constantly changing, the model formula of the photovoltaic array model needs to be revised. The revised formula is:

[0063]

[0064] in, , , They represent the ambient temperature, ambient temperature difference and ambient temperature reference value of the photovoltaic station respectively. , , Respectively represent light intensity, light intensity difference, and light intensity reference value. , Represent the photovoltaic array model The short-circuit current and the corrected short-circuit current, , , represents the correction factor, , Represent the photovoltaic array model The open circuit current and the corrected open circuit current, , Represent the photovoltaic array model The maximum power point voltage and the revised maximum power point voltage, Indicated by natural constant The logarithmic function with base .

[0065] Output current of photovoltaic array and light intensity , Input voltage and ambient temperature The relationship is:

[0066]

[0067] It represents the current output characteristics of the photovoltaic array under different light intensity, input voltage and temperature. To specify the value, the input and output of the photovoltaic array model adopt the per-unit system, and the input and output characteristic formula of the photovoltaic cell is calculated using the nominal system.

[0068] According to the droop control strategy, the photovoltaic station overall model is run to obtain the corresponding reactive power parameters. The corresponding specific process is:

[0069] According to the droop control strategy, the photovoltaic station overall model is run to obtain corresponding active and reactive power parameters, including:

[0070] The active power provided by the photovoltaic station in the overall photovoltaic station model , reactive power provided by photovoltaic stations ,Voltage ,frequency , Photovoltaic station active power set value , Photovoltaic station reactive power set value , PV station voltage set value Input to the station-level control model, and output the station-level active power control instruction , Station-level reactive power control instructions ;

[0071] The terminal voltage amplitude in the overall model of the photovoltaic station is , Reactive power at the machine end , Machine-side active power Input to the voltage ride-through state judgment module, and output the corresponding voltage ride-through state ;

[0072] The light intensity in the overall model of the photovoltaic station Input to the photovoltaic array model, and output the photovoltaic array output active power ;

[0073] The station-level active power control instruction , the station-level reactive power control instruction , the photovoltaic array outputs active power , Voltage Ride-Through State Input to the converter model, and output the reactive current component , active current component , that is, active and reactive power parameters.

[0074] Based on the active and reactive power parameters and the overall model of the photovoltaic station, a photovoltaic station reactive power control model is constructed, and the specific process is as follows:

[0075] Based on the active and reactive power parameters, the station-level control model and the converter model, a photovoltaic station reactive power control model is constructed; the photovoltaic station reactive power control model includes a photovoltaic station-level reactive power control model and a photovoltaic converter-level reactive power control model.

[0076] like Figure 4As shown, a photovoltaic station-level reactive power control model is established. The photovoltaic station-level reactive power control model includes station active power control and station reactive power control. Its control model belongs to the upper-level control of the wind farm. For example, the station reactive power control includes two control modes: 1) voltage PI control mode, 2) reactive power PI control mode. There are two control modes in the voltage PI control mode: constant voltage and reactive power droop. There are two control modes in the reactive power PI control mode: constant reactive power and constant power factor. The formula of the photovoltaic station-level reactive power control model is:

[0077]

[0078] in, represents the differential operator in the complex frequency domain, Represents the reactive power output by reactive PI control, , Indicates the leading and lagging time constant of reactive power command, Indicates the time constant of the measurement filter link, , , They represent the proportional, integral and reactive droop coefficients of the PI controller of the converter model respectively. , Represent voltage deviation and reference voltage respectively.

[0079] exist Figure 4 middle, Indicates the negative value of the deviation dead zone, Indicates a positive value of the deviation dead zone, , They represent the upper and lower limits of deviation respectively. Indicates the lower limit of reactive power control output, Indicates the upper limit of reactive power control output.

[0080] like Figure 5 As shown, a reactive power control model of the photovoltaic converter level is established. The converter-level control input can be a reactive power command calculated based on the initial power factor of the photovoltaic motor, or it can be the initial reactive power value of the photovoltaic generator or output under a certain station-level control mode. There are four control modes, namely open-loop control, reactive PI control, reactive / voltage coordinated control and constant reactive power control. In addition, the model also provides additional injection current control. Finally, the reactive current control command is output. The formula of the reactive power control model of the photovoltaic converter level is:

[0081]

[0082] in, , They represent the reactive current control command and reactive current injection amount of the converter station respectively. , , Respectively represent reactive power reference value, station-level reactive power control instruction, and reactive power actual value. Indicates the station-level reactive power control instruction.

[0083] exist Figure 5 middle, , , , Represents reactive power limit parameter, The reactive power after filtering, , Indicates the reactive current limit parameter.

[0084] Based on the reactive power control model of the photovoltaic station, the droop control coefficient is calculated to improve the transient stability of the DC transmission system. The specific process is as follows:

[0085] Running the photovoltaic station-level reactive power control model and the photovoltaic converter-level reactive power control model to obtain corresponding electrical quantities;

[0086] The droop control coefficient is calculated based on the electrical quantity, and the calculation formula is:

[0087]

[0088] in, , They represent the active power droop coefficient and reactive power droop coefficient respectively. , , , They respectively represent the rated angular frequency, rated active power, rated converter output voltage, and rated reactive power.

[0089] Based on the droop control coefficient, the droop control strategy is updated; and the updated droop control strategy is run to suppress the transient voltage of the photovoltaic station.

[0090] Photovoltaic array model The formula is:

[0091]

[0092] in, , , , respectively represent the output current, short-circuit current and maximum power point current of the photovoltaic array model, , They represent Changshu, , , They represent the open circuit voltage, output voltage and maximum power of the photovoltaic array model respectively. Indicated by natural constant The logarithmic function with base .

[0093] The present invention can achieve frequency and voltage stability by controlling the active and reactive outputs of the power supply respectively when transient voltage fluctuations occur in the DC transmission system, calculate the corresponding droop control coefficient, effectively distribute the power of the photovoltaic station, prevent the problem of unbalanced power distribution between inverters, effectively suppress the transient fluctuations of the photovoltaic station, and actively improve the stability of the DC transmission system.

[0094] A simulation example was built based on PSASP to verify the control strategy proposed in the present invention. The parameter design is shown in Table 1.

[0095] Table 1

[0096]

[0097] The steps of the verification method adopted by the present invention are:

[0098] The first step is to collect the electrical quantities of the required nodes based on the constructed simulation model;

[0099] The second step is to calculate the appropriate droop control coefficient;

[0100] The third step is to start the DC blocking device after the DC transmission system detects an abnormality or fault; the system cannot remove all filters in time, and a large amount of reactive power flows into the AC system, causing the reactive power capacity of the AC system to increase, causing the voltage at the sending end to rise. The scenario of DC blocking caused by DC disturbance is simulated, and the transient voltage rise on the photovoltaic side after DC blocking is recorded when droop control is not used;

[0101] The fourth step is to simulate the scenario of DC blocking caused by the droop control strategy adopted by the photovoltaic station, and then compare the transient overvoltage conditions on the photovoltaic station side before and after control.

[0102] In the operation scenario where the PV station does not use droop control, such as Figure 6 As shown, the bus voltage on the photovoltaic station side during normal operation is When DC blocking occurs, the transient voltage of the filter rises to , until it falls back after the filter is cut off.

[0103] By comparison Figure 6 and Figure 7The simulation results show that the DC transmission system adopts an active support strategy of photovoltaic stations based on droop control to suppress transient voltage. The transient voltage at the sending end is suppressed by controlling the reactive power output of the photovoltaic station. This method actively improves the stability of the DC transmission system.

[0104] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for actively suppressing transient voltage in a photovoltaic station based on droop control, characterized in that: include: Constructing a photovoltaic station overall model and formulating a droop control strategy for the photovoltaic station overall model; According to the droop control strategy, the photovoltaic station overall model is run to obtain corresponding active and reactive power parameters; Based on the active and reactive power parameters and the overall model of the photovoltaic station, a reactive power control model of the photovoltaic station is constructed; Calculating a droop control coefficient based on the photovoltaic station reactive power control model; Based on the droop control coefficient, the droop control strategy is updated; and the updated droop control strategy is run to suppress the transient voltage of the photovoltaic station.

2. A method for actively suppressing transient voltage in a photovoltaic station based on droop control according to claim 1, characterized in that: The overall model of the photovoltaic station includes a station-level control model, a voltage ride-through state judgment module, a photovoltaic array model, a control module and a converter model; wherein: Station-level control model, used to obtain station-level active power control instructions , Station-level reactive power control instructions , and input to the control module; The voltage ride-through state judgment module is used to determine the voltage amplitude at the machine end. , Reactive power at the machine end , machine end active power Determine the voltage ride-through state of the overall model of the photovoltaic station and obtain the corresponding voltage ride-through state , and input to the control module; Photovoltaic array model, used to calculate the , get the output power of the photovoltaic array , and input to the control module; A control module is used to control the reactive power according to the station level reactive power control instruction. , Station-level active power control instructions , terminal voltage amplitude , Reactive power at the machine end , machine end active power , Voltage Ride-Through State , PV array output power , determine the control strategy of the overall model of the photovoltaic station, and output the active current control instruction , reactive current control command to the converter model; wherein the control strategy includes normal operation control, voltage ride-through control and current ride-through control; A converter model for controlling the active current according to the input active current control command , reactive current control command , control strategy, output to obtain reactive current component , active current component .

3. A method for actively suppressing transient voltage in a photovoltaic station based on droop control according to claim 2, characterized in that: The formula of the photovoltaic array model is: in, , , They represent the ambient temperature, ambient temperature difference and ambient temperature reference value of the photovoltaic station respectively. , , Respectively represent light intensity, light intensity difference, and light intensity reference value. , Represent the photovoltaic array model The short-circuit current and the corrected short-circuit current, , , represents the correction factor, , Represent the photovoltaic array model The open circuit current and the corrected open circuit current, , Represent the photovoltaic array model The maximum power point voltage and the revised maximum power point voltage, Indicated by natural constant The logarithmic function with base .

4. A method for actively suppressing transient voltage in a photovoltaic station based on droop control according to claim 2, characterized in that: According to the droop control strategy, the photovoltaic station overall model is run to obtain corresponding active and reactive power parameters, including: The active power provided by the photovoltaic station in the overall photovoltaic station model , reactive power provided by photovoltaic stations ,Voltage ,frequency , Photovoltaic station active power set value , PV station reactive power set value , PV station voltage set value Input to the station-level control model, and output the station-level active power control instruction , Station-level reactive power control instructions ; The terminal voltage amplitude in the overall model of the photovoltaic station is , Reactive power at the machine end , machine end active power Input to the voltage ride-through state judgment module, and output the corresponding voltage ride-through state ; The light intensity in the overall model of the photovoltaic station Input to the photovoltaic array model, and output the photovoltaic array output active power ; The station-level active power control instruction , the station-level reactive power control instruction , the photovoltaic array outputs active power , Voltage Ride-Through State Input to the converter model, and output the reactive current component , active current component , that is, active and reactive power parameters.

5. A method for actively suppressing transient voltage in a photovoltaic station based on droop control according to claim 2, characterized in that: The reactive power control model of the photovoltaic station is constructed based on the active and reactive power parameters and the overall model of the photovoltaic station, and the specific process is as follows: Based on the active and reactive power parameters, the station-level control model and the converter model, a photovoltaic station reactive power control model is constructed; the photovoltaic station reactive power control model includes a photovoltaic station-level reactive power control model and a photovoltaic converter-level reactive power control model.

6. A method for actively suppressing transient voltage in a photovoltaic station based on droop control according to claim 4 or 5, characterized in that: The formula of the photovoltaic station-level reactive power control model is: ； in, represents the differential operator in the complex frequency domain, Represents the reactive power output by reactive PI control, , Indicates the leading and lagging time constant of reactive power command, Indicates the time constant of the measurement filter link, , , They represent the proportional, integral and reactive droop coefficients of the PI controller of the converter model respectively. , Represent voltage deviation and reference voltage respectively.

7. A method for actively suppressing transient voltage in a photovoltaic station based on droop control according to claim 6, characterized in that: The formula of the reactive power control model of the photovoltaic converter stage is: ； in, , They represent the reactive current control command and reactive current injection amount of the converter station respectively. , , Respectively represent reactive power reference value, station-level reactive power control instruction, and reactive power actual value. Indicates the station-level reactive power control instruction.

8. A method for actively suppressing transient voltage in a photovoltaic station based on droop control according to claim 5, characterized in that: The calculating of the droop control coefficient based on the photovoltaic station reactive power control model includes: Running the photovoltaic station-level reactive power control model and the photovoltaic converter-level reactive power control model to obtain corresponding electrical quantities; The droop control coefficient is calculated based on the electrical quantity, and the calculation formula is: ； in, , They represent the active power droop coefficient and reactive power droop coefficient respectively. , , , They respectively represent the rated angular frequency, rated active power, rated converter output voltage, and rated reactive power.

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