Penalties for Low Power Factor

With the in-depth implementation of "carbon peak" and "carbon neutrality" policies, distributed photovoltaic power stations in industries and commerce have emerged like mushrooms after rain, bringing not only green and clean energy to enterprises but also injecting new vitality into low-carbon living. However, in this green wave, an undeniable issue has gradually emerged - that is, the problem of power factor decline caused by photovoltaic grid connection.

I. The "Sweetness" and "Trouble" of Photovoltaic Power Stations

The grid connection of photovoltaic power stations undoubtedly brings significant economic and environmental benefits to industrial and commercial users. According to statistics, a distributed photovoltaic power station with a capacity of 1.2MW can reduce about 1,000 tons of carbon dioxide emissions annually. However, with the access of photovoltaic power stations, the reactive power issue of the power grid has gradually become prominent.

II. The "Root Cause" of the Power Factor Decline

So, what exactly causes the decline of the power factor? Taking the rooftop distributed photovoltaic power station project of a certain machinery company in Jiangsu as an example, we can find that before the grid connection of the photovoltaic power station, the power factor of the power grid was stable at around 0.95. However, since the grid connection of the photovoltaic power station, the power factor has gradually decreased to below 0.85, causing the company to be frequently fined by the power grid company.

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After in-depth analysis, we found that the root cause of the problem lies in the grid connection of the photovoltaic power station, which leads to a decrease in the active power output of the system, and the existing reactive power compensation system cannot accurately judge and compensate for the reactive power. Specifically, when the photovoltaic power station generates electricity, its output of active power is offset by the original load of the power grid, leading to a decrease in the active load of the power grid. However, the access of the photovoltaic power station also introduces additional reactive power, and the existing reactive power compensation system, due to technical limitations, cannot accurately judge and compensate for these reactive powers, thus leading to a decline in the power factor.Capacitive Power Factor Correction

III. Unveiling the "Culprit" Behind the Reduction of Power Factor

Characteristics of Photovoltaic Power Stations: Photovoltaic power generation produces direct current (DC), which is converted into alternating current (AC) by an inverter, and then there is a certain discrepancy in matching with the power grid. This discrepancy may lead to the generation and variation of reactive power. Statistics show that a 1.2MW photovoltaic power station may generate about 50kVar of reactive power per day.

Power Grid Environment and Load Conditions: Distributed photovoltaic power stations on the user side are usually connected to the internal power grid of enterprises, where inductive loads such as motors account for a large proportion. These loads generate reactive power during operation, and the connection of photovoltaic power stations changes the power supply load of the power grid, making the original reactive power compensation system unable to accurately judge and compensate for reactive power.

IV. Innovative Solutions

Faced with the problem of the decline in power factor, we propose the following innovative solutions:1. Intelligent Reactive Power Compensation System Upgrade: By introducing advanced sampling and computing technologies, the existing reactive power compensation system is upgraded to be intelligent. The new system can accurately collect real-time data of the power grid and photovoltaic power stations, and calculate the required reactive power compensation based on this data. According to tests, the new system can increase the power factor to above 0.92.

2. Photovoltaic Grid-Connected Specific Compensation Device: A specific compensation device designed and manufactured to match the photovoltaic grid-connected capacity. This device has the ability to monitor the power generation of photovoltaic power stations and the reactive power demand of the power grid in real time, and can automatically switch the parallel capacitor banks to meet the power factor requirements of the power grid. By accurately matching the power generation curve of the photovoltaic power station, dynamic balance of reactive power is achieved.

3. Harmonic Filtering and Compensation Integrated Device: For users with complex distribution network environments, multiple harmonic sources, and high difficulty in management, it is recommended to use a harmonic filtering and compensation integrated device. This device not only has the function of reactive power compensation but can also effectively filter out harmonics in the power grid, improving the quality of the power grid. Test data show that the device can reduce the harmonic content to below 5% while increasing the power factor to above 0.95.

The issue of power factor decline after the grid connection of photovoltaic power stations is not the fault of photovoltaic itself, but the result of multiple factors such as the power grid environment and load conditions. Through innovative solutions such as intelligent reactive power compensation system upgrades, photovoltaic grid-connected specific compensation devices, and harmonic filtering and compensation integrated devices, we can effectively address this issue, improve the power factor of the power grid, ensure the stable operation of the power grid, and protect the economic interests of users. Let us work together to create a green, low-carbon, and sustainable future!