The power sector has put strong focus on bridging the gap between power demand and supply, ensuring 24×7 supply and expanding electricity coverage to all consumer categories. While a number of programmes have been undertaken to achieve these ends, the issue of power quality has persisted for long. In the World Bank’s Global Competitiveness Report 2019, India ranked 108th amongst 141 countries on the reliability of electricity supply parameter, several notches lower than its 2018 ranking of 80th (amongst 137 economies). Further, as per a more recent survey of utilities by government think tank Niti Aayog, The Rockefeller Foundation and Smart Power India, while India has achieved 100 per cent household electrification, 28 per cent of consumers remain dissatisfied over the quality of electricity, that is, voltage fluctuations and power surges, and the resultant damage to appliances.
With the increasing penetration of renewables, the proliferation of electric vehicles (EVs) and charging facilities, and the rise of decentralised generation, the stress on the transmission and distribution grid has increased manyfold. This affects the quality of power supply, resulting in performance degradation, premature failure of electrical equipment, and increased systemic and financial losses. Further, the quality of power supply is hampered by natural calamities and increase in non-linear loads on the consumer side.
As per the Niti Aayog study, India may have achieved 100 per cent household electrification, but 28 per cent of consumers remain dissatisfied over the quality of electricity – voltage fluctuations and power surges – and the resultant damage to appliances. This means that customers have to either incur a higher additional cost for installing voltage stabilisers, or decide not to invest in electrical appliances that can be potentially damaged. The report finds that the problem increases during summer when consumers place a higher emphasis on the quality of electricity. Overall, only 55 per cent of the 25,000 surveyed customers expressed satisfaction with the quality of their electricity supply. The urban areas fared well with 66 per cent of consumers expressing satisfaction with the quality of electricity against 51 per cent in rural areas.
Gujarat West emerged as the best, with 95 per cent consumers expressing satisfaction over the quality of electricity. Karnataka was next, with three of five utilities – Karnataka Bangalore, Karnataka Mangalore and Karnataka Mysore – figuring in the top five utilities based on customer satisfaction, ranging from 82 per cent to 84 per cent. In Uttar Pradesh, except for Uttar Pradesh Kanpur, all the other four utilities were in the bottom five, with 70 per cent of consumers raising concerns over voltage fluctuations. Meghalaya stood last with only 12 per cent of consumers expressing satisfaction.
The proportion of satisfied consumers was the highest at 63 per cent in the institutional category, while the agricultural category had the lowest share of satisfied consumers at 51 per cent. In contrast, the majority, or 55 per cent, of household consumers reported satisfaction. Among agricultural customers, dissatisfaction with quality was the highest among farmers with a small and marginal land size (36 per cent each), and the least among farmers with large landholdings (4 per cent). For institutional customers, the proportion of satisfied customers is the lowest in the educational segment. Around 67 per cent of institutional customers from urban areas reported satisfaction with quality, while only 61 per cent of rural institutional customers were satisfied with their electricity quality.
Key PQ issues
Harmonics, one of the growing power quality issues, is caused by the non-linearity of customer loads. The harmonic currents flow upstream from non-linear loads through the impedance of cables and transformers, and create harmonic voltage distortion. Harmonic currents also create increased heating in electrical cables, leading to premature ageing, overstressed electrical insulation, nuisance tripping of protective devices, overheated conductors, etc.
With the expansion of EV charging infrastructure, power quality concerns such as brownouts, voltage issues and harmonics are also increasing. Meanwhile, discoms are struggling to strengthen the grid and maintain the high power quality environment given that they did not invest much capital in infrastructure earlier. Further, the absence of a robust grid and inefficient assets may also affect EV charging infrastructure. Besides the high cost of charging stations, power quality will define the reliability and sustainability of EV infrastructure.
The quality of supply and services significantly impacts customers’ perception and satisfaction level. The quality and reliability of supply relate to continuity, voltage and frequency variations, harmonics distortion, and power factor variations. Meanwhile, the quality of service relates to the overall customer experience. With increasing digitalisation and customer-focused business practices in other sectors, customer expectations from electric utilities have also increased. That said, both utilities and customers are affected by power supply quality and reliability issues. While utilities suffer from additional expenses due to frequent maintenance, repair of damaged equipment, loss of revenue, etc., customers have to deal with increased repairing costs of consumer electronics and unscheduled power cuts, leading to a high degree of inconvenience.
Standards and regulations
Customers are now becoming increasingly sensitive to the quality of supply and services. Even a small interruption in supply or voltage fluctuation is unacceptable and 24×7 supply is becoming the norm in most states. In view of this, various regulations have been issued by the Central Electricity Regulatory Commission and the Central Electricity Authority on power quality standards and parameters. Besides, power quality standards have been covered under various state regulations, standards of performance regulations and the grid code. These regulations prescribe limits for various quality- and reliability-related parameters such as the time duration for utilities to inform customers about scheduled outages, amount of compensation to be paid by utilities for unscheduled outages, and limits for voltage variations, limits for indices like system average interruption duration index and system average interruption frequency index.
However, these regulations are not uniform across the states and do not provide a comprehensive mechanism for monitoring the power quality and incentivising compliance, among other things. There are variations in similar power quality parameters specified by different state electricity regulatory commissions. Also, the penalties prescribed in case of non-compliance are low and there is a general lack of information pertaining to the amount of compensation actually paid by utilities to customers on account of such deficient services.
Owing to the absence of suitable metering infrastructure, electric utilities are not able to capture the quality and reliability of supply-related information at the customer’s end. Another stress factor is the cash-strapped distribution companies that manage power supply. They have no financial incentive to supply to the rural poor. Therefore, while physical connections have been added, the quality of power supply remains a concern.
The way ahead
To address these concerns, the Ministry of Power has recently announced the notification of the Electricity (Rights of Consumers) Rules, 2020. These rules lay down the rights of consumers, including a minimum standard of service for the supply of electricity, and the obligations of distribution licensees. They also cover parameters such as release of new connections and modification in the existing connection, metering arrangement, billing and payment. The rules specify that distribution licensees have to supply 24×7 power to all consumers. However, the commission may specify lower hours of supply for some categories of consumers such as agriculture. Distribution licensees have also been directed to put in place a mechanism, preferably with automated tools, for monitoring and restoring outages.
That said, specific power quality problems can be addressed through technical solutions. For instance, for inductive or capacitative loads (which cause voltage and current phase angles), power factor correction equipment can be
used. Harmonics due to non-linear loads can be addressed through static or dynamic filters. Similarly, transients can be addressed through the replacement of switches or transient suppression devices. Attending to the basics, such as earthing of systems and load balancing, is also important.
Apart from this, power quality improvement requires investments in power quality monitoring and technology assessment as well as strict enforcement of standards. Also, many industries are running inefficient motors, or heavy machines and induction motors. These could create a lot of grid disturbances and shocks such as overvoltages or undervoltages for a few seconds. In individual houses, too, a water pumping motor can cause voltage fluctuations. Hence, domestic users must be supported by stringent product standards issued by a national standards body such as the Bureau of Indian Standards. Also, capital investment in the distribution network is required to deliver quality power. Further, there is a need to bring consistency in the norms at the central and state levels by considering all relevant power quality parameters and aligning them with widely accepted international norms.
Power quality indices or key performance indicators (KPIs) need to be considered while evaluating the discoms’ standards of performance. Power quality KPIs include voltage variation, neutral voltage variation, voltage unbalance, dips, swells, transients, interruptions at the point of supply, and harmonics. Further, the uptake of smart systems must be mandated for networks to communicate real-time information and power quality deviations in upstream and downstream to all stakeholders.
The measurement and monitoring of harmonics is a largely ignored area. Therefore, specific provisions need to be created by the regulators to limit harmonics injection by consumers and utilities. Further, the penalties imposed on discoms for not complying with the voltage and harmonics limit should be increased. Penalties should be large enough to deter offenders of the regulations. Going forward, distribution utilities need to design and implement awareness programmes for consumers by engaging with them periodically through structured awareness programmes.