New energy grid-connected detection platform adjustable reactance control method

Abstract

The invention relates to an adjustable reactance control method for a new energy grid-connected detection platform, and belongs to the technical field of adjustable reactance. The method comprises the following five steps: defining a switching function; calculating a voltage value of a secondary winding; calculating a voltage value of a primary winding and a current value of the primary winding; calculating impedance of the primary winding; the impedance of the adjustable reactor can be changed by changing the duty ratio # imgabs0 #. When the # imgabs 1 # is increased, the impedance mode of the adjustable reactor is reduced; and when the # imgabs2 is reduced, the impedance of the adjustable reactor is increased. According to the method, the reactance can be linearly adjusted, the structure is simple, and engineering implementation is easy.

Description

Technical Field

[0001] The present invention belongs to the technical field of adjustable reactance control, and in particular relates to an adjustable reactance control method for a new energy grid-connected detection platform. Background Art

[0002] As one of the key industries for achieving the dual goals of "carbon peak and carbon neutrality", the power industry has the primary task of promoting low-carbon transformation of energy and realizing a new power system with green energy as the main body. Wind and solar power will become an important source of power supply. However, with the continuous increase in the penetration rate of new energy and the proportion of power electronic equipment in the system, the power grid has gradually shifted from a synchronous machine-dominated system to a converter-dominated system. The reduction in system inertia and the significant decrease in the short-circuit ratio of the common coupling point, the long-distance transmission lines and multi-stage transformers have led to a significant increase in grid impedance, and other characteristics, making the power grid present the characteristics of a weak grid or even an extremely weak grid. Therefore, the power grid has put forward higher requirements for the access of new energy and power electronic equipment. In order to simulate its reaction characteristics under external power grid faults, the application of a new energy grid-connected detection platform that simulates different fault states of the power grid is of great significance.

[0003] As a basic device in the new energy grid-connected detection platform, the adjustable reactor plays an important role in the stability and safety of the system. In addition, many problems such as harmonic suppression, overvoltage and overcurrent limitation can be solved by using adjustable impedance. Therefore, the new energy grid-connected detection platform should have the function of linearly adjustable reactance. However, it is currently difficult to accurately control the traditional turn-type reactor, so it cannot be continuously adjustable.

[0004] On May 10, 2024, Chinese invention patent application CN118017531A disclosed a method for controlling an adjustable reactance. The method uses controllable devices to adjust the primary side reactance winding by controlling the switch of the thyristor and the output current of the transistor, thereby achieving arbitrary adjustment of the impedance. The switch control of the thyristor achieves coarse adjustment of the adjustable reactance, and the transistor output current control achieves fine adjustment of the adjustable reactance. Although this method can perform coarse and fine adjustments on the adjustable reactor, the number of devices used is large and the cost is high, the volume is large and the control is relatively complex, which makes it difficult to implement in the new energy grid-connected detection platform.

[0005] On April 19, 2024, China's invention patent CN117912820A disclosed a PWM-type series resonant adjustable reactor for vector inspection and its control method. The adjustable capacitor and adjustable inductor under PWM chopping control form a series resonant circuit to compress the volume of the adjustable reactor; and a freewheeling loop is provided in the adjustable reactor topology structure. Under high-frequency PWM control, the sinusoidal current output by the adjustable reactor has low harmonic content and will not affect the system to be tested, solving the technical problem of coupling high-frequency harmonics in PWM chopping control. Although this method is continuously adjustable for the reactance and compresses the volume, it requires the use of multiple IGBTs, MOSFETs and other devices, and the control system is relatively complex.

[0006] Therefore, how to overcome the shortcomings of the existing technology is an urgent problem to be solved in the field of adjustable reactance control technology. Summary of the invention

[0007] The purpose of the present invention is to solve the deficiencies of the prior art and to provide a method for controlling an adjustable reactance of a new energy grid-connected detection platform to achieve linear regulation of the reactance of the new energy grid-connected test platform.

[0008] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0009] A method for controlling an adjustable reactance of a new energy grid-connected detection platform, wherein the new energy grid-connected detection platform comprises a rectifier unit, a DC power supply, an inverter unit, an adjustable reactance and a transformer;

[0010] The three-phase input voltage is connected to the DC power supply through the rectifier unit, the DC power supply is connected to the DC side of the inverter unit, and the AC side of the inverter unit is connected to the device under test through the transformer after being output by the adjustable reactance;

[0011] The adjustable reactance includes an S1 tube, an S2 tube, a primary winding and a secondary winding. The S1 tube and the S2 tube are both composed of an IGBT and an anti-parallel diode. The S1 and S2 tubes are reversely connected in series in the circuit; the emitter of the S1 tube IGBT is connected to the emitter of the S2 tube IGBT, the collectors of the two IGBTs are connected to the two ends of the secondary winding, and the gate of the S1 tube IGBT and the gate of the S2 tube IGBT are respectively connected to a PWM generator;

[0012] The adjustable reactance control method of the new energy grid-connected detection platform comprises the following steps:

[0013] Step (1), defining a switching function f to control the on / off of the S1 IGBT and the S2 IGBT, and the S1 IGBT and the S2 IGBT are turned on complementary to each other;

[0014]

[0015] Perform Fourier expansion on f:

[0016]

[0017] In the formula, α is the duty cycle of the IGBT conduction, k is the ratio of the secondary winding voltage period to the PWM wave period, F(α, k) is the Fourier expansion term; n is an integer in [1,∞], ω is the angular frequency, and t is time;

[0018] F(α,k)=sin(nωτ)+sin[nω(T c +τ)]-sinnωT c +sin[nω(2T c +τ)]

[0019] In the formula, τ is the conduction time of the PWM wave, ω is the voltage angular frequency, T c is the period of the PWM wave;

[0020] Step (2), when the PWM wave is used to control the on and off of the IGBT tube, the S1 tube and the S2 tube are alternately turned on and off. The actual voltage value of the secondary winding is calculated by step (1), ignoring the high-order harmonics and only considering the fundamental wave to obtain:

[0021] u2=fU N sinωt=αU N sinωt

[0022] Where u2 is the actual voltage of the secondary winding, U N is the rated voltage of the secondary winding, and the impedance value of the secondary winding is Z2, and the current value i2 of the secondary winding is obtained:

[0023]

[0024] Step (3), according to step (2), the current of the secondary winding is obtained, and the turns ratio of the primary winding to the secondary winding is set to N, and the voltage U of the primary winding is obtained. N1 and the current value i1 of the primary winding;

[0025] Step (4): According to step (3), the voltage U of the primary winding is obtained. N1 The impedance Z1 of the primary winding is obtained by calculating the current value i1 of the primary winding;

[0026] Step (5), according to the result obtained in step (4), pulses with different duty cycles are sent through the PWM generator, and the current of the secondary winding of the adjustable inductor is changed by changing the conduction and shutdown of the S1 tube and the S2 tube. The generated reverse magnetic flux changes the core magnetic resistance of the adjustable inductor, thereby realizing continuous adjustable inductance value.

[0027] Further, preferably, the inverter unit is a DC / AC inverter unit.

[0028] Further, preferably, the transformer is an isolation step-up transformer.

[0029] Furthermore, preferably, the equipment under test is a wind turbine, a photovoltaic device, or an energy storage device.

[0030] Further, preferably, in step (3), the voltage U of the primary winding is N1 The calculation formula of the primary winding current value i1 is as follows:

[0031]

[0032] Therefore, the primary winding current is:

[0033]

[0034] Further, preferably, in step (4), the impedance Z1 of the primary winding is calculated by the following formula:

[0035]

[0036] The present invention can change the impedance of the adjustable reactor by changing the duty cycle α. When α increases, the modulus of the impedance of the adjustable reactor decreases; when α decreases, the impedance of the adjustable reactor increases.

[0037] In the present invention, when the S1 tube IGBT is fully turned on, the current of the secondary winding is the maximum, thereby making the current of the primary winding the maximum, and the resistance of the adjustable reactor becomes smaller. Similarly, when the S1 tube IGBT is fully turned off, the secondary winding is equivalent to a circuit breaker and no current is generated, the current of the primary winding reaches the minimum value, and the resistance of the adjustable reactor reaches the maximum at this time. By changing the duty cycle of the IGBT, the adjustable reactor can be continuously adjusted within the power supply cycle, which is the core of the technology of the present invention.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] The present invention provides an adjustable reactance control method for a new energy grid-connected detection platform. The method can linearly adjust the reactance, has a simple structure, and is easy to implement in engineering. The IGBT tube is used. The device is small in size and is a high-frequency switching device with a fast response speed. Only a small LC filter is required to remove high-order harmonics, which reduces harmonic pollution. Figure 3 The simulation model of the adjustable reactor of the new energy grid-connected detection platform shown in Table 1 can obtain the impedance data under different duty cycles.

[0040] Table 1 Simulation data under different duty cycles

[0041] PWM duty cycle α <![CDATA[Primary winding voltage U N1 > <![CDATA[Primary winding current i1]]> <![CDATA[Adjustable reactor impedance Z1]]> 0 193.0V 0.054A 3574.07Ω 0.2 190.7V 0.065A 2933.85Ω 0.5 170.2V 0.167A 1019.16Ω 0.8 146.1V 0.288A 507.29Ω 1 88.38V 0.577A 153.17Ω

[0042] It can be seen from Table 1 that as the duty cycle of the PWM wave increases, the primary winding voltage of the adjustable reactor decreases, the primary winding current increases as the duty cycle increases, and the primary winding impedance value of the adjustable reactor decreases as the duty cycle increases, thus achieving linear adjustability of the adjustable reactor. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 This is the topology diagram of the new energy grid-connected detection platform;

[0044] Figure 2 This is the control principle diagram of the adjustable reactor of the new energy grid-connected detection platform;

[0045] Figure 3 This is a simulation diagram of the adjustable reactor of the new energy grid-connected detection platform. DETAILED DESCRIPTION

[0046] The present invention is further described in detail below in conjunction with embodiments.

[0047] Those skilled in the art will appreciate that the following examples are only used to illustrate the present invention and should not be considered to limit the scope of the present invention. If no specific techniques or conditions are specified in the examples, the techniques or conditions described in the literature in the art or the product specifications are used. If the manufacturer of the materials or equipment used is not specified, they are all conventional products that can be purchased.

[0048] Example 1

[0049] A method for controlling an adjustable reactance of a new energy grid-connected detection platform, wherein the new energy grid-connected detection platform comprises a rectifier unit, a DC power supply, an inverter unit, an adjustable reactance and a transformer;

[0050] The three-phase input voltage is connected to the DC power supply through the rectifier unit, the DC power supply is connected to the DC side of the inverter unit, and the AC side of the inverter unit is connected to the device under test through the transformer after being output by the adjustable reactance;

[0051] The adjustable reactance includes an S1 tube, an S2 tube, a primary winding and a secondary winding. The S1 tube and the S2 tube are both composed of an IGBT and an anti-parallel diode. The S1 and S2 tubes are reversely connected in series in the circuit; the emitter of the S1 tube IGBT is connected to the emitter of the S2 tube IGBT, the collectors of the two IGBTs are connected to the two ends of the secondary winding, and the gate of the S1 tube IGBT and the gate of the S2 tube IGBT are respectively connected to a PWM generator;

[0052] The adjustable reactance control method of the new energy grid-connected detection platform comprises the following steps:

[0053] Step (1), defining a switching function f to control the on / off of the S1 IGBT and the S2 IGBT, and the S1 IGBT and the S2 IGBT are turned on complementary to each other;

[0054]

[0055] Perform Fourier expansion on f:

[0056]

[0057] In the formula, α is the duty cycle of the IGBT conduction, k is the ratio of the secondary winding voltage period to the PWM wave period, F(α, k) is the Fourier expansion term; n is an integer in [1,∞], ω is the angular frequency, and t is time;

[0058] F(α,k)=sin(nωτ)+sin[nω(T c +τ)]-sinnωT c +sin[nω(2T c +τ)]

[0059] In the formula, τ is the conduction time of the PWM wave, ω is the voltage angular frequency, T c is the period of the PWM wave;

[0060] Step (2), when the PWM wave is used to control the on and off of the IGBT tube, the S1 tube and the S2 tube are alternately turned on and off. The actual voltage value of the secondary winding is calculated by step (1), ignoring the high-order harmonics and only considering the fundamental wave to obtain:

[0061] u2=fU N sinωt=αU N sinωt

[0062] Where u2 is the actual voltage of the secondary winding, U N is the rated voltage of the secondary winding, and the impedance value of the secondary winding is Z2, and the current value i2 of the secondary winding is obtained:

[0063]

[0064] Step (3), according to step (2), the current of the secondary winding is obtained, and the turns ratio of the primary winding to the secondary winding is set to N, and the voltage U of the primary winding is obtained. N1 and the current value i1 of the primary winding;

[0065] Step (4): According to step (3), the voltage U of the primary winding is obtained. N1 The impedance Z1 of the primary winding is obtained by calculating the current value i1 of the primary winding;

[0066] Step (5), according to the result obtained in step (4), pulses with different duty cycles are sent through the PWM generator, and the current of the secondary winding of the adjustable inductor is changed by changing the conduction and shutdown of the S1 tube and the S2 tube. The generated reverse magnetic flux changes the core magnetic resistance of the adjustable inductor, thereby realizing continuous adjustable inductance value.

[0067] Example 2

[0068] A method for controlling an adjustable reactance of a new energy grid-connected detection platform, wherein the new energy grid-connected detection platform comprises a rectifier unit, a DC power supply, an inverter unit, an adjustable reactance and a transformer;

[0069] The three-phase input voltage is connected to the DC power supply through the rectifier unit, the DC power supply is connected to the DC side of the inverter unit, and the AC side of the inverter unit is connected to the device under test through the transformer after being output by the adjustable reactance;

[0070] The adjustable reactance includes an S1 tube, an S2 tube, a primary winding and a secondary winding. The S1 tube and the S2 tube are both composed of an IGBT and an anti-parallel diode. The S1 and S2 tubes are reversely connected in series in the circuit; the emitter of the S1 tube IGBT is connected to the emitter of the S2 tube IGBT, the collectors of the two IGBTs are connected to the two ends of the secondary winding, and the gate of the S1 tube IGBT and the gate of the S2 tube IGBT are respectively connected to a PWM generator;

[0071] The adjustable reactance control method of the new energy grid-connected detection platform comprises the following steps:

[0072] Step (1), defining a switching function f to control the on / off of the S1 IGBT and the S2 IGBT, and the S1 IGBT and the S2 IGBT are turned on complementary to each other;

[0073]

[0074] Perform Fourier expansion on f:

[0075]

[0076] In the formula, α is the duty cycle of the IGBT conduction, k is the ratio of the secondary winding voltage period to the PWM wave period, F(α, k) is the Fourier expansion term; n is an integer in [1,∞], ω is the angular frequency, and t is time;

[0077] F(α,k)=sin(nωτ)+sin[nω(T c +τ)]-sinnωT c +sin[nω(2T c +τ)]

[0078] In the formula, τ is the conduction time of the PWM wave, ω is the voltage angular frequency, Tc is the period of the PWM wave;

[0079] Step (2), when the PWM wave is used to control the on and off of the IGBT tube, the S1 tube and the S2 tube are alternately turned on and off. The actual voltage value of the secondary winding is calculated by step (1), ignoring the high-order harmonics and only considering the fundamental wave to obtain:

[0080] u2=fU N sinωt=αU N sinωt

[0081] Where u2 is the actual voltage of the secondary winding, U N is the rated voltage of the secondary winding, and the impedance value of the secondary winding is Z2, and the current value i2 of the secondary winding is obtained:

[0082]

[0083] Step (3), according to step (2), the current of the secondary winding is obtained, and the turns ratio of the primary winding to the secondary winding is set to N, and the voltage U of the primary winding is obtained. N1 and the current value i1 of the primary winding;

[0084] Step (4): According to step (3), the voltage U of the primary winding is obtained. N1 The impedance Z1 of the primary winding is obtained by calculating the current value i1 of the primary winding;

[0085] Step (5), according to the result obtained in step (4), pulses with different duty cycles are sent through the PWM generator, and the current of the secondary winding of the adjustable inductor is changed by changing the conduction and shutdown of the S1 tube and the S2 tube. The generated reverse magnetic flux changes the core magnetic resistance of the adjustable inductor, thereby realizing continuous adjustable inductance value.

[0086] The inverter unit is a DC / AC inverter unit.

[0087] The transformer is an isolation step-up transformer.

[0088] The equipment under test is wind turbine, photovoltaic and energy storage equipment.

[0089] In step (3), the voltage U of the primary winding N1 The calculation formula of the primary winding current value i1 is as follows:

[0090]

[0091] Therefore, the primary winding current is:

[0092]

[0093] In step (4), the impedance Z1 of the primary winding is calculated as follows:

[0094]

[0095] Example 3

[0096] like Figure 1 As shown, a method for controlling an adjustable reactance of a new energy grid-connected detection platform is provided, wherein the new energy grid-connected detection platform comprises a rectifier unit, a DC power supply, an inverter unit, an adjustable reactance and a transformer; the inverter unit is a DC / AC inverter unit. The transformer is an isolation step-up transformer. The equipment under test is a wind turbine, a photovoltaic device and an energy storage device.

[0097] The three-phase input voltage is connected to the DC power supply through the rectifier unit, the DC power supply is connected to the DC side of the DC / AC inverter unit, and the AC side of the DC / AC inverter unit is connected to the device under test through an isolation step-up transformer after the adjustable reactance filter output, wherein the device under test is a wind turbine, photovoltaic or energy storage device;

[0098] like Figure 2 As shown, the sampling bidirectional IGBT tube is turned on and off by PWM control, thereby realizing the control of the secondary winding current, and the purpose of adjusting the inductance of the adjustable reactor is achieved by changing the size of the reverse magnetic flux generated by the secondary winding.

[0099] Step (1), defining a switching function f to control the on / off of the S1 IGBT and the S2 IGBT, and the S1 IGBT and the S2 IGBT are turned on complementary to each other;

[0100]

[0101] Perform Fourier expansion on f:

[0102]

[0103] In the formula, α is the duty cycle of the IGBT conduction, k is the ratio of the secondary winding voltage period to the PWM wave period, F(α, k) is the Fourier expansion term; n is an integer in [1,∞], ω is the angular frequency, and t is time;

[0104] F(α,k)=sin(nωτ)+sin[nω(T c +τ)]-sinnωT c +sin[nω(2T c +τ)]

[0105] In the formula, τ is the conduction time of the PWM wave, ω is the voltage angular frequency, T c is the period of the PWM wave;

[0106] Step (2), when the PWM wave is used to control the on and off of the IGBT tube, the S1 tube and the S2 tube are alternately turned on and off. The actual voltage value of the secondary winding is calculated by step (1), ignoring the high-order harmonics and only considering the fundamental wave to obtain:

[0107] u2=fU N sinωt=αU N sinωt

[0108] Where u2 is the actual voltage of the secondary winding, U N is the rated voltage of the secondary winding, and the impedance value of the secondary winding is Z2, and the current value i2 of the secondary winding is obtained:

[0109]

[0110] Step (3), according to step (2), the current of the secondary winding is obtained, and the turns ratio of the primary winding to the secondary winding is set to N, and the voltage U of the primary winding is obtained. N1 With current value i1:

[0111]

[0112] Therefore, the primary winding current is:

[0113]

[0114] Step (4), according to step (3), the voltage and current values ​​of the primary winding are obtained, and the impedance Z1 of the primary winding is obtained by calculation, and the calculation formula is as follows:

[0115]

[0116] Step (5), according to the result obtained in step (4), pulses with different duty cycles are sent through PWM, and the current of the secondary winding of the adjustable reactor is changed by changing the on and off of S1 and S2. The generated reverse magnetic flux changes the core magnetic resistance of the adjustable reactor, thereby realizing continuous adjustable inductance. The impedance of the adjustable reactor can be changed by changing the duty cycle α. When α increases, the modulus of the impedance of the adjustable reactor decreases; when α decreases, the impedance of the adjustable reactor increases.

[0117] The present invention provides an adjustable reactance control method for a new energy grid-connected detection platform. The method can linearly adjust the reactance, has a simple structure, and is easy to implement in engineering. The IGBT tube is used. The device is small in size and is a high-frequency switching device with a fast response speed. Only a small LC filter is required to remove high-order harmonics, which reduces harmonic pollution. Figure 3 The simulation model of the adjustable reactor of the new energy grid-connected detection platform shown in Table 1 can obtain the impedance data under different duty cycles.

[0118] Table 1 Simulation data under different duty cycles

[0119] PWM duty cycle α <![CDATA[Primary winding voltage U N1 > <![CDATA[Primary winding current i1]]> <![CDATA[Adjustable reactor impedance Z1]]> 0 193.0V 0.054A 3574.07Ω 0.2 190.7V 0.065A 2933.85Ω 0.5 170.2V 0.167A 1019.16Ω 0.8 146.1V 0.288A 507.29Ω 1 88.38V 0.577A 153.17Ω

[0120] It can be seen from Table 1 that as the duty cycle of the PWM wave increases, the primary winding voltage of the adjustable reactor decreases, the primary winding current increases as the duty cycle increases, and the primary winding impedance value of the adjustable reactor decreases as the duty cycle increases, thus achieving linear adjustability of the adjustable reactor.

[0121] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for controlling adjustable reactance of a new energy grid-connected detection platform, characterized in that: The new energy grid-connected detection platform includes a rectifier unit, a DC power supply, an inverter unit, an adjustable reactor and a transformer; The three-phase input voltage is connected to the DC power supply through the rectifier unit, the DC power supply is connected to the DC side of the inverter unit, and the AC side of the inverter unit is connected to the device under test through the transformer after being output by the adjustable reactance; The adjustable reactance includes an S1 tube, an S2 tube, a primary winding and a secondary winding. The S1 tube and the S2 tube are both composed of an IGBT and an anti-parallel diode. The S1 and S2 tubes are reversely connected in series in the circuit; the emitter of the S1 tube IGBT is connected to the emitter of the S2 tube IGBT, the collectors of the two IGBTs are connected to the two ends of the secondary winding, and the gate of the S1 tube IGBT and the gate of the S2 tube IGBT are respectively connected to a PWM generator; The adjustable reactance control method of the new energy grid-connected detection platform comprises the following steps: Step (1), defining a switching function f to control the on / off of the S1 IGBT and the S2 IGBT, and the S1 IGBT and the S2 IGBT are turned on complementary to each other; Perform Fourier expansion on f: In the formula, α is the duty cycle of the IGBT conduction, k is the ratio of the secondary winding voltage period to the PWM wave period, F(α, k) is the Fourier expansion term; n is an integer in [1,∞], ω is the angular frequency, and t is time; F(α,k)=sin(nω)+sin[nω(T c +τ)]-sinnωT c +sin[nω(2T c +t)] In the formula, τ is the conduction time of the PWM wave, ω is the voltage angular frequency, T c is the period of the PWM wave; Step (2), when the PWM wave is used to control the on and off of the IGBT tube, the S1 tube and the S2 tube are alternately turned on and off. The actual voltage value of the secondary winding is calculated by step (1), ignoring the high-order harmonics and only considering the fundamental wave to obtain: u2=fU N sinωt=αU N sinωt Where u2 is the actual voltage of the secondary winding, U N is the rated voltage of the secondary winding, and the impedance value of the secondary winding is Z2, and the current value i2 of the secondary winding is obtained: Step (3), according to step (2), the current of the secondary winding is obtained, and the turns ratio of the primary winding to the secondary winding is set to N, and the voltage U of the primary winding is obtained. N1 and the current value i1 of the primary winding; Step (4): According to step (3), the voltage U of the primary winding is obtained. N1 The impedance Z1 of the primary winding is obtained by calculating the current value i1 of the primary winding; Step (5), according to the result obtained in step (4), pulses with different duty cycles are sent through the PWM generator, and the current of the secondary winding of the adjustable inductor is changed by changing the conduction and shutdown of the S1 tube and the S2 tube. The generated reverse magnetic flux changes the core magnetic resistance of the adjustable inductor, thereby realizing continuous adjustable inductance value.

2. The adjustable reactance control method of the new energy grid-connected detection platform according to claim 1 is characterized in that: The inverter unit is a DC / AC inverter unit.

3. The adjustable reactance control method of the new energy grid-connected detection platform according to claim 1 is characterized in that: The transformer is an isolation step-up transformer.

4. The adjustable reactance control method of the new energy grid-connected detection platform according to claim 1 is characterized in that: The equipment under test is wind turbine, photovoltaic and energy storage equipment.

5. The adjustable reactance control method of the new energy grid-connected detection platform according to claim 1 is characterized in that: In step (3), the voltage U of the primary winding N1 The calculation formula of the primary winding current value i1 is as follows: Therefore, the primary winding current is:

6. The adjustable reactance control method of the new energy grid-connected detection platform according to claim 1 is characterized in that: In step (4), the impedance Z1 of the primary winding is calculated as follows:

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