阅读说明：本技术 一种光伏逆变器的耦合电感电流优化、漏电流抑制的调制方法 (Modulation method for optimizing coupling inductance current and suppressing leakage current of photovoltaic inverter ) 是由 苏位峰 宇文博 高强 蒲绍宁 谢永昌 张旭方 冯哲 王茫 张东岳 于 2019-07-03 设计创作，主要内容包括：本发明公开了一种光伏逆变器的耦合电感电流优化、漏电流抑制的调制方法,包括如下步骤：S1：对光伏逆变器设置断路器和电压传感器,断路器和电压传感器均与控制器连接；S2：对光伏逆变器内部添加滤波电路；S3：对所述的滤波电路进行测试,控制不同开关的闭合,检测对应的光伏逆变器系统中共模电压的变化量；S4：光伏逆变器内部设置漏电流传感器,并将漏电流传感器与控制器相连接；本发明通过对光伏逆变器设置断路器、电压传感器、漏电流传感器、滤波电路以及控制器,通过滤波电路不同的开关闭合,带来电路中共模电压的变化,通过算法优化开关组合逻辑,从而抑制系统电压波动,对漏电流产生抑制。(the invention discloses a modulation method for optimizing coupling inductance current and inhibiting leakage current of a photovoltaic inverter, which comprises the following steps of: s1: a circuit breaker and a voltage sensor are arranged on the photovoltaic inverter, and both the circuit breaker and the voltage sensor are connected with a controller; s2: a filter circuit is added in the photovoltaic inverter; s3: testing the filter circuit, controlling the closing of different switches, and detecting the variation of common-mode voltage in the corresponding photovoltaic inverter system; s4: a leakage current sensor is arranged in the photovoltaic inverter and is connected with the controller; according to the invention, the photovoltaic inverter is provided with the circuit breaker, the voltage sensor, the leakage current sensor, the filter circuit and the controller, the common-mode voltage in the circuit is changed by closing different switches of the filter circuit, and the switch combination logic is optimized through an algorithm, so that the voltage fluctuation of the system is inhibited, and the leakage current is inhibited.)

1. A modulation method for optimizing coupling inductance current and suppressing leakage current of a photovoltaic inverter is characterized by comprising the following steps: comprises the following steps of (a) carrying out,

S1: a circuit breaker and a voltage sensor are arranged on the photovoltaic inverter, and both the circuit breaker and the voltage sensor are connected with a controller;

S2: a filter circuit is added in the photovoltaic inverter;

S3: testing the filter circuit, controlling the closing of different switches, and detecting the variation of common-mode voltage in the corresponding photovoltaic inverter system;

S4: and a leakage current sensor is arranged in the photovoltaic inverter and is connected with the controller.

2. The modulation method for optimizing the coupling inductance current and suppressing the leakage current of the photovoltaic inverter according to claim 1, wherein the modulation method comprises the following steps: in step S1, the circuit breaker, the voltage sensor, and the controller are connected by wire.

3. The modulation method for optimizing the coupling inductance current and suppressing the leakage current of the photovoltaic inverter according to claim 1, wherein the modulation method comprises the following steps: in the step S1, the circuit breaker and the photovoltaic inverter are connected in series and connected to a power supply; the photovoltaic inverter and the voltage sensor are connected in parallel.

4. the modulation method for optimizing the coupling inductance current and suppressing the leakage current of the photovoltaic inverter according to claim 1, wherein the modulation method comprises the following steps: in the step S2, the filter circuit is any one of a full H4 bridge topology circuit, an H5 topology circuit, a HERIC topology circuit, an H6 topology circuit, and an H6.5 topology circuit.

5. The modulation method for optimizing the coupling inductance current and suppressing the leakage current of the photovoltaic inverter according to claim 1, wherein the modulation method comprises the following steps: in step S3, all switch combination modes of the filter circuit are tested, the voltage sensors are used as test results, the voltage sensor results are in one-to-one correspondence with the switch combinations, and the switch combination logic is optimized through an algorithm in the controller.

6. The modulation method for optimizing the coupling inductance current and suppressing the leakage current of the photovoltaic inverter according to claim 1, wherein the modulation method comprises the following steps: in step S4, the circuit sensor detects the leakage current, is connected in series with the photovoltaic inverter, and is connected to the power line.

7. the modulation method for optimizing the coupling inductance current and suppressing the leakage current of the photovoltaic inverter according to claim 1, wherein the modulation method comprises the following steps: in step S4, the range of the leakage current sensor is 0.5-100 mA.

Technical Field

The invention relates to a modulation method for current optimization and leakage current suppression, in particular to a modulation method for coupling inductance current optimization and leakage current suppression of a photovoltaic inverter.

Background

In recent years, rapid growth of photovoltaic power generation, in which a photovoltaic inverter is a core component that converts direct current into alternating current, has played a great role in solving the problems of world energy shortage and environmental pollution.

However, the parasitic capacitance on the photovoltaic panel in the photovoltaic inverter system inevitably generates the leakage current. The leakage current can increase the electromagnetic interference of the system, so that the waveform of the output current is distorted, and huge potential safety hazards are brought to equipment and operators.

Disclosure of Invention

The invention aims to provide a modulation method for optimizing coupling inductance current and inhibiting leakage current of a photovoltaic inverter, so as to solve the problems in the background technology.

In order to achieve the purpose, the invention provides the following technical scheme: a modulation method for optimizing coupling inductance current and suppressing leakage current of a photovoltaic inverter comprises the following steps,

S1: a circuit breaker and a voltage sensor are arranged on the photovoltaic inverter, and both the circuit breaker and the voltage sensor are connected with a controller;

S2: a filter circuit is added in the photovoltaic inverter;

S3: testing the filter circuit, controlling the closing of different switches, and detecting the variation of common-mode voltage in the corresponding photovoltaic inverter system;

S4: and a leakage current sensor is arranged in the photovoltaic inverter and is connected with the controller.

preferably, in step S1, the circuit breaker, the voltage sensor, and the controller are connected by a wire.

Preferably, in step S1, the circuit breaker and the photovoltaic inverter are connected in series and connected to a power supply; the photovoltaic inverter and the voltage sensor are connected in parallel.

Preferably, in step S2, the filter circuit is any one of a full H4 bridge topology circuit, an H5 topology circuit, a HERIC topology circuit, an H6 topology circuit, and an H6.5 topology circuit.

Preferably, in step S3, all the switch combination modes of the filter circuit are tested, the voltage sensors are used as the test results, and the results of the voltage sensors correspond to the switch combinations one by one, and the switch combination logic is optimized through an algorithm in the controller.

preferably, in step S4, the circuit sensor detects a leakage current, is connected in series with the photovoltaic inverter, and is connected to a power line.

Preferably, in step S4, the range of the leakage current sensor is 0.5 to 100 mA.

compared with the prior art, the invention has the beneficial effects that: according to the photovoltaic inverter, the breaker, the voltage sensor, the leakage current sensor, the filter circuit and the controller are arranged on the photovoltaic inverter, the common-mode voltage in the circuit is changed by closing different switches of the filter circuit, and the switch combination logic is optimized through an algorithm, so that the voltage fluctuation of the system is restrained, the leakage current is restrained, and the safety of normal operation of equipment and the safety of maintenance workers are effectively guaranteed.

Drawings

FIG. 1 is a schematic flow chart of the steps of 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. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 1, the present invention provides a technical solution: a modulation method for optimizing coupling inductance current and suppressing leakage current of a photovoltaic inverter comprises the following steps,

s1: a circuit breaker and a voltage sensor are arranged on the photovoltaic inverter, and both the circuit breaker and the voltage sensor are connected with a controller;

S2: a filter circuit is added in the photovoltaic inverter;

S3: testing the filter circuit, controlling the closing of different switches, and detecting the variation of common-mode voltage in the corresponding photovoltaic inverter system;

S4: and a leakage current sensor is arranged in the photovoltaic inverter and is connected with the controller.

Further, in step S1, the circuit breaker, the voltage sensor, and the controller are connected by a wire.

Further, in the step S1, the circuit breaker and the photovoltaic inverter are connected in series and connected to a power supply; the photovoltaic inverter and the voltage sensor are connected in parallel.

Further, in the step S2, the filter circuit is any one of a full H4 bridge topology circuit, an H5 topology circuit, a HERIC topology circuit, an H6 topology circuit, and an H6.5 topology circuit.

Further, in step S3, all switch combination modes of the filter circuit are tested, the voltage sensors are used as test results, and the results of the voltage sensors correspond to the switch combinations one by one, and the switch combination logic is optimized through an algorithm in the controller.

Further, in step S4, the circuit sensor detects a leakage current, is connected in series with the photovoltaic inverter, and is connected to the power line.

further, in the step S4, the range of the leakage current sensor is 0.5 to 100 mA.

The working principle is as follows: in step S1, the photovoltaic inverter is provided with a circuit breaker and a voltage sensor for cutting off the inverter voltage and detecting the inverter common mode voltage, connected to the controller, and automatically controlled by the controller; in step S2, a filter circuit is provided for the photovoltaic inverter, and the common-mode voltage of the photovoltaic inverter is influenced by the filter circuit, so as to ensure that the common-mode voltage is maintained in a stable interval or value, thereby suppressing the leakage current; in step S3, the influence on the common mode voltage is detected by detecting different switch combinations, and the common mode voltage is optimized by an algorithm, so that the common mode voltage is maintained stable; in step S4, a leakage current sensor is provided, connected to the ground line, capable of detecting leakage current in the line; the detection range of the sensor is 0.5-100 mA, and the change of leakage current can be accurately captured; when the leakage current is too large, the signal is fed back to the controller, the circuit breaker is controlled to work through the controller, the power supply is disconnected, and finally, a fire disaster is avoided or damage is caused to maintenance workers.

The whole method detects the real-time state of the photovoltaic inverter, ensures the normal work of the photovoltaic inverter, enables the photovoltaic inverter to be maintained in a stable working state and ensures the working efficiency.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.