阅读说明：本技术 光伏逆变器控制方法 (Photovoltaic inverter control method ) 是由 王凯 于 2019-10-11 设计创作，主要内容包括：本发明公开了光伏逆变器控制方法,包括DC/AC变换器模块和DC/AC逆变器模块,所述DC/AC变换器模块电路采用推挽式电路,DC/DC变换器由推挽逆变电路、高频变压器、整流电路和滤波电感构成,它将太阳能电池板输出的62V的直流电压转换成400V的直流电压,DC/AC逆变器的主电路采用全桥式结构,由4个MOS管构成,所述MOS管内部寄生了反并联的二极管,它将400V的直流电转换成为220V/50Hz的工频交流电,所述DC/AC变换器控制电路是以集成电路SG3525为核心,由SG3525输出的两路50kHz的驱动信号,经门极驱动电路加在推挽电路开关管Q1和Q2的门极上。本发明实现限制输出过流过压的保护功能,保障太阳能发电的设备安全以及负载的使用寿命,输出电流能够很好地跟踪电网电压波形。(The invention discloses a photovoltaic inverter control method, which comprises a DC/AC converter module and a DC/AC inverter module, the DC/AC converter module circuit adopts a push-pull circuit, the DC/DC converter is composed of a push-pull inverter circuit, a high-frequency transformer, a rectifying circuit and a filter inductor and converts 62V direct current voltage output by a solar panel into 400V direct current voltage, a main circuit of the DC/AC converter adopts a full-bridge structure and is composed of 4 MOS tubes, an anti-parallel diode is parasitized in the MOS tube, 400V direct current is converted into 220V/50Hz power frequency alternating current, the DC/AC converter control circuit takes an integrated circuit SG3525 as a core, and two paths of 50kHz driving signals output by SG3525 are applied to gates of switching tubes Q1 and Q2 of a push-pull circuit through a gate driving circuit. The invention realizes the protection function of limiting output overcurrent and overvoltage, ensures the safety of solar power generation equipment and the service life of a load, and can well track the voltage waveform of a power grid by output current.)

1. The photovoltaic inverter control method is characterized in that a DC/AC converter module circuit adopts a push-pull circuit, the DC/DC converter is composed of a push-pull inverter circuit, a high-frequency transformer, a rectifying circuit and a filter inductor and converts 62V direct current voltage output by a solar panel into 400V direct current voltage, a main circuit of the DC/AC inverter adopts a full-bridge structure and is composed of 4 MOS (metal oxide semiconductor) tubes, and anti-parallel diodes are parasitized in the MOS tubes and convert the 400V direct current into 220V/50Hz power frequency alternating current.

2. the method of claim 1, wherein the DC/AC converter control circuit is based on an integrated circuit SG3525, and two 50kHz driving signals outputted from SG3525 are applied to gates of the push-pull switching transistors Q1 and Q2 through a gate driving circuit.

3. In order to keep the output voltage of the DC/DC converter stable, the detected output voltage is compared with the command voltage, the error voltage controls the duty ratio of the output driving signal of SG3525 after passing through a PI regulator, when the output current of the DC/DC converter is detected to be overlarge, SG3525 reduces the width of a gate pulse and the output voltage, and when the output voltage is overhigh, the operation of the DC/DC converter is stopped.

4. The pv inverter control method of claim 1, wherein the core DC/AC inverter control chip is a TMS320F240 chip, and the TMS320F240 chip control software includes four programs, i.e., a main program, a T1 underflow interrupt program, a T2 underflow interrupt program, and a sync interrupt program.

5. The pv inverter control method of claim 3 wherein the T1 underflow interrupt routine occurs once every 50 μ β, the routine being primarily for generating PWM waves.

6. The pv inverter control method of claim 3 wherein the T2 underflow interrupt routine occurs once every 10ms, the routine being used primarily to generate the current command.

7. The pv inverter control method of claim 3 wherein the sync break routine occurs every 10ms to 30 ms.

Technical Field

The invention relates to the field of photovoltaic power generation, in particular to a photovoltaic inverter control method.

Background

Photovoltaic power generation is a technology of directly converting light energy into electric energy by using the photovoltaic effect of a semiconductor interface. The solar energy power generation system mainly comprises a solar panel, a controller and an inverter, and the main components of the system are electronic components.

The photovoltaic inverter is an important element in the photovoltaic power generation process, the main function of the inverter is to connect the solar energy converted into electric energy with a power grid or a load, and the inverter has an important transition function.

Disclosure of Invention

the invention aims to solve the defects in the prior art and provides a photovoltaic inverter control method.

In order to achieve the purpose, the invention adopts the following technical scheme:

The photovoltaic inverter control method comprises a DC/AC converter module and a DC/AC inverter module, wherein the DC/AC converter module circuit adopts a push-pull circuit, the DC/DC converter is composed of a push-pull inverter circuit, a high-frequency transformer, a rectifying circuit and a filter inductor and converts 62V direct current voltage output by a solar panel into 400V direct current voltage, a main circuit of the DC/AC inverter adopts a full-bridge structure and is composed of 4 MOS tubes, and anti-parallel diodes are parasitized in the MOS tubes and convert the 400V direct current into 220V/50Hz power frequency alternating current.

Preferably, the DC/AC converter control circuit is based on an integrated circuit SG3525, and two 50kHz driving signals output from SG3525 are applied to gates of the push-pull switching transistors Q1 and Q2 through a gate driving circuit. In order to keep the output voltage of the DC/DC converter stable, the detected output voltage is compared with the command voltage, the error voltage controls the duty ratio of the output driving signal of SG3525 after passing through a PI regulator, when the output current of the DC/DC converter is detected to be overlarge, SG3525 reduces the width of a gate pulse and the output voltage, and when the output voltage is overhigh, the operation of the DC/DC converter is stopped.

Preferably, the core control chip of the DC/AC inverter adopts a TMS320F240 chip, and the TMS320F240 chip control software includes four programs, namely a main program, a T1 underflow interrupt program, a T2 underflow interrupt program and a synchronous interrupt program.

Preferably, the T1 underflow interrupt routine occurs every 50 μ s, and the routine is primarily used to generate PWM waves.

Preferably, the T2 underflow interrupt routine occurs every 10ms, and the routine is primarily used to generate a current command.

Preferably, the sync interrupt routine occurs every 10ms to 30 ms.

The invention has the beneficial effects that:

1. When the DC/DC converter output current is detected to be overlarge, SG3525 reduces the width of a gate pulse, reduces the output voltage and further reduces the output current. When the output voltage is too high, the DC/DC converter stops working, so that the protection function of limiting output overcurrent and overvoltage is realized, and the safety of solar power generation equipment and the service life of a load are guaranteed.

2. the topological structure of the DC/DC controller adopts a push-pull circuit, and is controlled by a chip SG3525, the circuit effectively prevents magnetic biasing, the DC/AC inverter is a full-bridge inverter circuit and is controlled by a DSP, and the output current of the inverter can well track the voltage waveform of a power grid because the computing speed of the DSP is higher.

Drawings

Fig. 1 is a schematic circuit block diagram of a photovoltaic inverter control method according to the present invention;

FIG. 2 is a topological diagram of a DC/AC converter of the photovoltaic inverter control method according to the present invention;

Fig. 3 is a flow chart of TMS320F240 software control of the pv inverter control method according to the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.