CN-122026727-A - Converter suitable for energy conversion of direct current and alternating current power grid and control method thereof

CN122026727ACN 122026727 ACN122026727 ACN 122026727ACN-122026727-A

Abstract

The invention discloses a converter adapting to energy conversion of a direct current and alternating current power grid and a control method thereof, wherein the converter comprises a primary side control unit, a primary side switch unit, a secondary side control unit, a secondary side switch unit and a transformer; the secondary side of the transformer is provided with a tap, the power input end of the primary side switch unit is used for connecting a power supply, the output end of the primary side switch unit is respectively connected with the first acquisition end of the primary side control unit and the primary side of the transformer, the control input end of the primary side switch unit is connected with the first output end of the primary side control unit, the input end of the secondary side switch unit is connected with the secondary side of the transformer, the output end of the secondary side switch unit and the tap of the transformer are respectively used for being connected with two ends of a load to form a loop, the second acquisition end of the primary side switch unit is used for being connected with the load to acquire load electric signals, and the control input end of the secondary side switch unit is connected with the data output end of the primary side control unit or the primary side gate of the transformer to realize direct current-direct current conversion and direct current-alternating current conversion.

Inventors

REN CHUNGUANG
DONG TIANTIAN
WANG ZIXUAN
LI XINCHI
WU JINDE
HAN XIAOQING

Assignees

太原理工大学

Dates

Publication Date: 20260512
Application Date: 20260122

Claims (10)

1. The converter suitable for the energy conversion of the direct current and alternating current power grids is characterized by comprising a primary side control unit, a primary side switch unit, a secondary side control unit, a secondary side switch unit and a transformer, wherein a tap is arranged on the secondary side of the transformer; The power input end of the primary side switch unit is used for connecting a power supply, and the output end of the primary side switch unit is respectively connected with the first acquisition end of the primary side control unit and the primary side of the transformer; The input end of the secondary side switch unit is connected with the secondary side of the transformer, and the output end of the secondary side switch unit and the tap of the transformer are respectively connected with two ends of a load to form a loop; The second acquisition end of the primary side control unit is used for being connected with a load to acquire a load electric signal; and the control input end of the secondary side switch unit is connected with the data output end of the primary side control unit or the primary side gate of the transformer.
2. A method for controlling a converter adapted for dc and ac power grid energy conversion, applied to a converter adapted for dc and ac power grid energy conversion as claimed in claim 1, the method comprising: acquiring an output state instruction; The control input end of the secondary side switch unit is controlled to be connected with the data output end of the primary side control unit if the output state instruction is AC output, the primary side control unit generates a first switch signal according to the collected load electric signal and sends the first switch signal to the primary side switch unit, and the secondary side control unit generates a second switch signal according to the load electric signal and sends the second switch signal to the secondary side switch unit; And if the output state instruction is direct current output, controlling the control input end of the secondary side switch unit to be connected with the primary side of the transformer, generating a third switch signal by the primary side control unit according to the collected load electric signal and the current sampling value collected by the first collecting end, and sending the third switch signal to the primary side switch unit, collecting the primary side signal by the secondary side control unit, generating a fourth switch signal according to the primary side signal, and sending the fourth switch signal to the secondary side switch unit.
3. A method of controlling a converter adapted for dc and ac power grid energy conversion according to claim 2, wherein said primary side control unit generating a first switching signal from said load electrical signal comprises: The primary side control unit acquires a current signal in the load electric signal, carries out orthogonal signal processing on the current signal to obtain a stationary current orthogonal component corresponding to the current signal, and acquires a grid angle, a grid frequency and a rotating voltage orthogonal component in the load electric signal according to a phase-locked loop; and generating the first switching signal according to the stationary current quadrature component, the power grid angle, the power grid frequency and the voltage component.
4. A method of controlling a converter adapted for dc and ac grid energy conversion according to claim 3, wherein said generating said first switching signal based on said quiescent current quadrature component, grid angle, grid frequency and rotational voltage component comprises: Synchronizing the stationary current orthogonal component to the coordinate of the rotating voltage component according to the power grid angle to obtain a rotating current component; proportional integration is carried out on the rotating current component to obtain a first regulating voltage component; Performing voltage change on the rotating current component to obtain a second regulating voltage component; Superposing the first regulating voltage component and the second regulating voltage component to obtain a regulating voltage orthogonal component; And the primary side control unit acquires the resonant frequency and generates the first switching signal according to the orthogonal component of the regulating voltage, the resonant frequency and the rotating voltage component.
5. The method of controlling a converter adapted for dc and ac power grid energy conversion according to claim 4, wherein said proportional-integrating said rotating current component to obtain a first regulated voltage component comprises: the primary side control unit acquires a reference current component, calculates current deviation of the reference current component and the rotating current component, and performs proportional integral processing on the current deviation to obtain the first regulating voltage component.
6. The method of controlling a converter adapted for dc and ac power grid energy conversion according to claim 4, wherein said voltage varying said rotating current component to obtain a second regulated voltage component comprises: The primary side control unit obtains the angular speed of the power grid and the inductance value of the load; And carrying out voltage change on the rotating current component according to the angular speed and the inductance value of the power grid to obtain the second regulating voltage component.
7. The method of controlling a converter adapted for dc and ac power grid energy conversion according to claim 2, wherein said secondary side control unit generating a second switching signal from said load electrical signal comprises: The secondary side control unit acquires an adjusting voltage quadrature component and a power grid angle, calculates a phase angle according to the adjusting voltage quadrature component, stacks the power grid angle and the phase angle, then processes the power grid angle and the phase angle through a sine function to obtain a modulation wave, and inputs the modulation wave into the positive electrode of the comparator to obtain the second switching signal.
8. The method according to claim 2, wherein the primary control unit generates a third switching signal according to the collected load electrical signal and the current sampling value collected by the first collecting terminal, and the method comprises: The primary side control unit obtains a voltage sampling value and a voltage reference value according to the load electric signal; And obtaining the third switching signal according to the voltage sampling value, the voltage reference value and the current sampling value.
9. The method of claim 8, wherein obtaining the third switching signal from the voltage sample value, the voltage reference value, and the current sample value comprises: The primary side control unit performs proportional integral conversion on the deviation between the voltage sampling value and the voltage reference value to obtain a current reference value; calculating the current deviation of the current reference value and the current sampling value, and performing proportional-integral conversion on the current deviation to obtain a generated modulation voltage; Converting the modulation voltage into a switching frequency by a voltage-controlled oscillator in the primary side control unit; and generating the third switching signal by the PWM module in the primary side control unit.
10. The method of claim 2, wherein the secondary control unit collects primary signals, and generating a fourth switching signal according to the primary signals comprises: the secondary side control unit collects primary side current signals, the primary side current signals are input into the positive electrode of the comparator, and the comparator outputs the fourth switching signals.

Description

Converter suitable for energy conversion of direct current and alternating current power grid and control method thereof Technical Field The invention relates to the technical field of inverters, in particular to a converter adapting to energy conversion of a direct current and alternating current power grid and a control method thereof. Background In the prior art, in order to enable the power supply to have the capability of accessing an alternating current or direct current power grid at the same time, two independent sets of conversion devices (DC/DC and DC/AC) are generally required to be respectively configured. However, configuring two independent systems not only increases the configuration cost, but also increases the difficulty of system control. Disclosure of Invention The invention aims to solve the technical problem of providing a converter suitable for energy conversion of a direct current power grid and an alternating current power grid and a control method thereof, and the converter is used for realizing direct current-direct current conversion and direct current-alternating current conversion under different output requirement scenes based on one set of equipment. In order to solve the technical problems, the invention adopts the following technical scheme: The transformer is suitable for direct current and alternating current power grid energy conversion, a primary side control unit, a primary side switch unit, a secondary side control unit, a secondary side switch unit and a transformer are arranged on the secondary side of the transformer, a tap is arranged on the secondary side of the transformer, a power input end of the primary side switch unit is used for being connected with a power supply, an output end of the primary side switch unit is respectively connected with a first acquisition end of the primary side control unit and the primary side of the transformer, a control input end of the primary side switch unit is connected with a first output end of the primary side control unit, an input end of the secondary side switch unit is connected with the secondary side of the transformer, an output end of the secondary side switch unit and the tap of the transformer are respectively used for being connected with two ends of a load to form a loop, a second acquisition end of the primary side switch unit is used for being connected with the load to acquire a load electric signal, and a control input end of the secondary side switch unit is connected with a data output end of the primary side control unit or a primary side of the transformer to gate. In order to solve the technical problems, the invention adopts another technical scheme that: A control method of a converter adapted to dc and ac power grid energy conversion is applied to a converter adapted to dc and ac power grid energy conversion as described above, and the method includes: acquiring an output state instruction; The control input end of the secondary side switch unit is controlled to be connected with the data output end of the primary side control unit if the output state instruction is AC output, the primary side control unit generates a first switch signal according to the collected load electric signal and sends the first switch signal to the primary side switch unit, and the secondary side control unit generates a second switch signal according to the load electric signal and sends the second switch signal to the secondary side switch unit; And if the output state instruction is direct current output, controlling the control input end of the secondary side switch unit to be connected with the primary side of the transformer, generating a third switch signal by the primary side control unit according to the collected load electric signal and the current sampling value collected by the first collecting end, and sending the third switch signal to the primary side switch unit, collecting the primary side signal by the secondary side control unit, generating a fourth switch signal according to the primary side signal, and sending the fourth switch signal to the secondary side switch unit. The principle of the invention is as follows: When the output state instruction is AC output, the control input end of the secondary side switch unit is controlled to be connected with the data output end of the primary side control unit, at the moment, the primary side control unit generates a first switch signal (difference frequency control) according to the load electric signal to control the primary side switch unit, the primary side switch unit forms high-frequency AC current with low-frequency envelope on the primary side of the transformer through the difference frequency control, and the secondary side control unit generates a second switch signal according to the load electric signal to control the secondary side switch unit, so that the secondary side switch unit realizes synchronous rectification and polarity switching, and f