Power Quality

Many types of loads and network conditions can introduce power quality issues. Inductive loads, such as AC motors, draw significant reactive power, which can result in a low power factor¹. Non-linear loads like any electronic equipment, arc welders, arc furnaces, motor drives, cooling systems of data centers and others can introduce harmonics. Connection or disconnection of large loads and integration of renewables may additionally cause significant voltage variations.

_{1. Excessive capacitive loads like very long transmission lines on very low load can also impact power factor.}

Poor power quality significantly affects grid reliability and operational efficiency. Excessive stress due to harmonics and voltage instability affects lifetime of connected equipment and may cause premature failures which require unplanned maintenance and replacement activities.

Additionally, power quality issues limit the grid’s capacity to integrate renewables and hampers the effective running of sensitive installations like processing facilities, hospitals, and data centers. They also contribute to increased losses, which in turn cause extra heating in transformers, cables and components.

Hitachi Energy offers a wide range of solutions, from passive products such as capacitors and reactors, including passive filters and Metal Enclosed Capacitor Bank solutions, to advanced power electronics-based active harmonic filters, STATCOM’s and static var compensators (SVC). We also offer phase-shifting transformers and special transformers equipped with power quality features. Each power quality challenge requires a tailored solution. As a technology leader, Hitachi Energy can diagnose the power quality issue(s) the customer is facing and offer the best-suited solution from its low, medium and high- voltage portfolio.

Good power quality is an enabler for an efficient and effective electrical system and customer operations. Voltages remain stable resulting in loads running smoother and producing with higher quality, and currents remain within design limits minimizing the risk of supply interruptions. Renewable sources can inject clean power into the grid more efficiently. Additional benefits include the ability to integrate higher loads without excessive infrastructure investments. Optimized power quality also minimizes the need for additional power generation, possibly leading to lower CO₂ emissions. Improving power quality reduces costs for both consumers and producers, while also extending the lifespan of equipment. 

Yes. Poor power quality can adversely affect renewable energy systems, just as it does with conventional electrical installations.  In addition, renewable energy systems can be a source of poor power quality, which needs to be managed. When power generation and power need are not in balance, grid voltage will fluctuate, affecting all loads connected to the same grid.  Harmonic pollution generated by solar and wind inverters aggregate at the connection point and creates background distortion, often at higher frequencies. Finally, the renewable farms require reactive power that needs to be managed.