The crucial role of regulations in maintaining power quality
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IBT: Can you please tell us about Clariant Power System Limited?
Baldev Raj Narang: Clariant Power System Limited (CPSL) is a rapidly expanding company specializing in power quality and reactive power management. We provide comprehensive solutions and design systems across various sectors, including industry, utilities, renewables, and OEMs, serving both substantial electricity consumers and producers. CPSL has harnessed my extensive experience gained from working in various public and private enterprises. I initiated my career at BRPL (Bongaigaon Refinery and Petrochemicals Limited), a pioneering integrated oil refinery and petrochemicals project in India, executed by Engineers India Limited. Subsequently, I transitioned to Century Enka Limited, a Birla Group company engaged in polyester, nylon, and tire yarn production with international collaborations. My association with CPSL has allowed me to leverage my expertise. Although CPSL was already established, it has become one of the fastest-growing companies in its sector, and I am thrilled to contribute to its growth journey.
IBT: With the increasing penetration of renewable energy sources into the grid, what are the primary challenges or issues the energy industry faces in transitioning from conventional sources to renewables? Also, what remedies or strategies can address these challenges?
Baldev Raj Narang: The integration of renewable energy into the grid presents a significant challenge, with issues related to grid stability, power quality, and voltage stability. In 2022, there were 28 instances of renewable energy source isolation from the grid, resulting in a loss of over 1000 megawatts of power. The Central Authority (CA) recognized this and mandated changes, emphasizing the need for reactive power support, particularly dynamic support. While STATCOM (Static Synchronous Compensator) is a better solution than traditional switch capacitor banks, the problems run deeper.
These isolations often occur after faults, and the weak grid infrastructure in remote areas where renewable sources are located exacerbates the issue. Faults are not cleared in a timely manner due to poor short-circuit ratios and inertia. This leads to systems going out of synchronization. Addressing the problem comprehensively involves adding synchronous generators to improve grid stability, especially in areas with weak grids. Grid inverters need to be grid-forming rather than grid-following to enhance inertia. Strengthening the grid and ensuring proper inverter selection, tuning, and system modelling is crucial for sustainable renewable energy integration.
In summary, simply adding renewable sources without addressing grid stability concerns will not yield the desired results. Comprehensive measures are required to ensure a sustainable and reliable grid with renewable energy integration.
IBT: What is the current power quality status in the energy sector and how do renewable energy sources impact power quality? Also, sir, what measures can mitigate any negative effects?
Baldev Raj Narang: The current power quality status in the energy sector is poor, primarily due to a high concentration of nonlinear loads. In the past, linear loads were dominant, but the situation has reversed, with nonlinear loads now making up the majority. These nonlinear loads generate harmonics, which are a significant cause of power quality issues. These harmonics are mainly produced at the consumer end and need to be mitigated at the load end. If left unaddressed, these harmonics propagate back into the system as current harmonics, converting into voltage harmonics and affecting various nodes in the grid.
The issue with power quality is that consumers often do not take action unless these harmonics become a problem for them. Mitigating these harmonics requires regulatory measures because investments in such solutions depend on a clear return on investment (ROI). Currently, regulations related to power quality are nearly non-existent in most states. Tamil Nadu is an exception, having implemented tariff structures with penalties for feeding harmonics to the grid beyond specific IEEE 519 guidelines. This approach proved effective in driving action among consumers. However, other states have only been discussing such measures without implementing them in regulations or tariff structures. Thus, power quality issues persist, and regulations are essential to drive necessary investments and actions.
Regarding the impact of renewable energy sources on power quality, these sources also generate harmonics, but they tend to produce higher-order harmonics, typically from the 23rd harmonic and onwards. Unlike the lower-order harmonics generated by standard industry loads, these higher-order harmonics are more challenging to compensate. Active solutions for these high-order harmonics at the 33 kV level, where renewable sources are connected, are not readily available. Passive solutions, such as standard harmonics filters, are not suitable for higher-order harmonics. Specialized solutions are required, but as of now, there have been limited installations in India effectively addressing these issues.
While there are successful solutions in Australia and South Africa, India is still in the early stages of implementing measures to mitigate these higher-order harmonics generated by renewable energy sources. Progress is being made, but tangible results on the ground have yet to be observed.
IBT: What innovative solutions or technologies hold promise for enhancing grid voltage stability and addressing power quality issues resulting from the integration of renewable energy sources?
Baldev Raj Narang: The solutions for addressing power quality issues are not considered innovative; they are standard and well-established practices. In India, particularly at the 33 kV level for voltage stability, active solutions, like dynamic voltage support systems (such as STATCOMs), are still emerging and can be considered innovative. The Central Authority (CA) has recently mandated STATCOMs for voltage support. These solutions provide fast, dynamic responses, typically within milliseconds, to maintain voltage stability. However, they have not yet been widely implemented in actual installations.
On the other hand, passive solutions for voltage stability have been available and implemented. These solutions rely on reactive power support to maintain voltage levels. However, earlier renewable energy installations lacked reactive power support, and there was no mandate for such support within their premises. This led to a deficiency of reactive power support in the grid. While utilities have their own reactive power installations, they cannot accommodate the significant addition of renewable power without support from renewable energy sources.
To address this issue, CA has mandated that renewable energy sources should provide approximately 33% reactive power support. The requirement has led to some confusion about whether this support should be dynamic, active, passive, or a hybrid of these solutions. In general, there is a preference for dynamic support, but it may vary on a case-by-case basis. However, people tend to adopt these solutions only when they are essential. For instance, in Madhya Pradesh (MP), a tariff structure charges for the consumed reactive energy, which has incentivized the adoption of these solutions. In other cases, regulatory mandates or specific tariff structures may be necessary to drive the adoption of reactive power support solutions.
Importantly, dynamic support solutions are preferable for their speed and effectiveness. However, they have not yet been widely adopted in India because the country does not manufacture 33 kV dynamic support systems domestically. Renewable energy systems are typically connected at 33 kV, and they may need to rely on imported solutions. Over time, there may be a shift towards indigenous manufacturing in this field.
IBT: During the transition to renewable energy, what strategies or best practices can utilities adopt to ensure a smooth transition while maintaining high power quality standards?
Baldev Raj Narang: Two years ago, when we began addressing power quality and reactive power management, the regulations and guidelines were in place, but they were not being effectively implemented. As a result, developers and stakeholders did not voluntarily incorporate reactive power support or power quality measures into their systems. These initiatives are typically not taken up without regulatory compulsion or incentives.
The key to improving the situation is the implementation and enforcement of regulations. Properly designed and enforced regulations can drive the adoption of better voltage and power quality standards. Regulatory authorities should take the lead in initiating these strategies, and they can introduce penalties for non-compliance or offer incentives through tariff structures to encourage adherence to the regulations.
Without these regulatory measures, the power quality situation is likely to remain unchanged, and there is a risk of further disruptions and outages due to the lack of support systems, as has been observed with numerous grid isolations.
IBT: In the context of grid voltage, stability and power quality, how do regulatory frameworks and government policies influence the transition to sustainable energy sources? How can they be optimized to support reliability and sustainability while minimizing disruptions to pass supply?
Baldev Raj Narang: Government policies and regulatory frameworks play a crucial role in driving investments in power quality and ensuring that power quality is maintained. Without these policies and regulations, there is often a lack of incentive for stakeholders to invest in power quality measures. For instance, the Central Authority (CA) has mandated that power quality measures be in place before allowing connections to the grid, and these regulations are essential for improving power quality.
Nonlinear loads are a primary cause of power quality deterioration. To address this, regulatory frameworks and incentives can be used. There is already an emphasis on energy efficiency, which is a self-driven concept because it offers a return on investment (ROI). However, energy efficiency measures often introduce nonlinear loads, negatively impacting power quality. While consumers may seek ROI on power quality measures, power quality improvements typically have little to no ROI. Therefore, it is essential to have a regulatory framework in place to encourage investments in power quality.
Maintaining power quality is not only essential for preventing disruptions but also for safety. For instance, issues with poor power quality, such as harmonics and neutral conductor problems, can lead to fires in commercial buildings. To mitigate these risks, it is necessary to mandate and enforce regulations related to cabling networks, conductor sizing, and other safety aspects.
In summary, regulatory frameworks and government policies are critical to ensure that power quality is maintained and that investments are made to improve power quality, despite the challenges of ROI. These regulations not only benefit the stability of the power system but also enhance safety in various installations.