Power quality management of photovoltaic equipment
The addition of photovoltaic power generation equipment to an enterprise can bring many benefits to the enterprise. Enterprise users use the original idle factory roof to install photovoltaic power generation systems, which not only utilizes idle resources, but also reduces the energy consumption of the enterprise, plays a role in energy conservation and emission reduction. The enterprise can ease energy consumption expenses, and the excess electricity can be sold online, bringing economic benefits to the enterprise.
However, after adding photovoltaic power generation equipment, the system power factor is greatly reduced, causing electricity bill fines. In addition, the photovoltaic inverter will generate harmonics and transmit them to the power grid, which will deteriorate the power quality of the power grid, increase system losses, and affect power distribution and production safety. Therefore, while photovoltaic power generation, it is necessary to add SVG static reactive generators. While compensating for the reactive power of the system, it can manage a small number of low-order harmonics generated by photovoltaics, thereby purifying the power grid, saving energy and reducing consumption, and reducing electricity bills.
Power quality problems caused by photovoltaic equipment
Photovoltaic can cause a significant decrease in the power supply system's power factor. The main reason is that the active power required by the load is supplied by photovoltaics, which greatly reduces the active power output by the transformer, thereby greatly reducing the power factor of the high voltage metering point, causing the power factor to be seriously substandard when the power supply company assesses the power factor. In addition, when the photovoltaic installed capacity is large, a small part of reactive power will be accompanied by the output of active power, resulting in reactive power reverse transmission. This part of reactive power flows to the power grid, causing the power factor to be over-compensated.
In addition, the inverter is the main component of photovoltaic power generation equipment, and the inverter rectifier circuit is a common harmonic source in the power grid. When photovoltaics is working, harmonics, mainly 5th and 7th harmonics, are generated in the distribution system, and the harmonic current distortion rate is about 5% to 20%.
Pain points of power quality management of photovoltaic equipment
After the enterprise adds photovoltaic equipment, the power factor is reduced, and the photovoltaic power generation changes frequently. The original capacitor compensation speed is slow, and the capacity is insufficient, which cannot meet the requirements. This directly causes the power supply company to fine users and increase users' electricity bills.
After the increase of photovoltaic power, the harmonics generated by the photovoltaic inverter flow to the power grid, causing safety hazards. For effective management, filtering equipment must be added.
Power quality management plan for photovoltaic equipment
The harmonic current generated by photovoltaic power is not large, but it causes the system power factor to be very low, so the management plan is mainly to compensate for reactive power and to manage harmonics as a supplement. Shanghai Xixing Technology EasyPQ-SVG series static reactive generator can compensate for system reactive power and can compensate the power factor to 0.99. At the same time, it can also manage 2~13 harmonics, and the harmonic filtering rate reaches 90%, which comprehensively solves the power quality problems generated by photovoltaic power.
