Low & Medium Voltage Distribution

Voltage classifications typically consist of high, medium, and low voltages. From an international perspective, these classifications and ranges will vary depending on where you live. Energy production, transmission and distribution is being changed by the Industrial Internet of Things (IIoT). Two-way communication makes resources more efficient and gives customers more control over their resource better utilization.

As the electricity distribution industry transforms, grid operators, regulators, suppliers, and consumers face a new set of opportunities and challenges. Transmission and power distribution product suppliers now need to meet new IIoT requirements, such as cybersecurity and interoperability.

As distributed energy resources (DERs) and renewable energy gain momentum, demand is increasing for proven technologies that can connect to the grid in a mutually beneficial way. As data analytics and artificial intelligence become more prevalent, they are changing the way system operators and consumers make critical decisions. And a record number of smart homes and cities are adopting smart power distribution devices.

Low & Medium voltage Distribution

Depending on the amount of energy required for a facility, it may be possible to deliver power at low voltage (LV: up to 1 kV), medium voltage (1 to 35 kV), or high voltage. For small and medium power consumers, low voltage has been the obvious choice.Real-world facilities include a mix of power consumers served at different voltage levels based on the needs of the equipment.

Low Voltage (LV) Distribution

A distribution system that operates on the voltage levels that are directly utilized without any further reduction. Alternatively, it's called low tension (LT) distribution system or secondary distribution system. The low voltage distribution system carries electrical power from the distribution transformer to the energy meter of the consumer as part of the electrical power distribution network.

The vast majority of low voltage distribution systems in India are operated with an AC rated voltage of 230/415 V at 50 Hz. A low-voltage distribution system consists of the following components: -

  • Distributor - A distributor is the conductor from which tapings are supplied to customers. Since tapings are taken at various points along its length, the current running through the distributor isn't constant.
  • Distribution Transformer - In a distribution transformer, the primary winding is delta-connected and the secondary winding is star-connected. It distributes power to the distribution centers.
  • Service Mains - Essentially, it is a small cable that connects the electricity meter of the consumer to the distributor.

Advantages of using low voltage

A low voltage supply is one with an alternating current of 600 volts or less. It's most commonly found in industrial plants. For convenience of use, low voltage is split into supply and control. Low-voltage direct current serves numerous benefits. Using low-voltage electrical devices, for instance, reduces costs while increasing safety. Low-voltage power helps energy efficiency as well. The majority of renewable energy sources, such as solar, hydro, and wind, produce low direct current power.

Some gadgets, on the other hand, use a combination of low and high voltage to boost performance. Despite this, the balance is moving in favor of low-voltage systems, particularly in lighting. This transition can be seen in the development of light-emitting diodes. Ambient light such as track and cove lighting is another illustration of the shifting balance.

Medium Voltage (MV) Distribution

When we talk about Medium Voltage; in the whole transmission and distribution system, the MV network plays an important role because it is the point at which users start consuming electricity.The major objective of the MV network is to convert power from the sub-transmission level, which is generally 66kV or 132kV, to the medium voltage level, which is either 6.6kV, 11kV, 17.5kV, 24kV, or 40kV in some countries.

Advantages of using medium voltage

Copper's price has gone up 400 percent in the last ten years, from $0.77 per lb to $4 per lb. Contractors, design engineers, and facility owners are looking for solutions to reduce the amount of copper in the distribution model as the cost rises. Implementing medium-voltage distribution systems is one method. The purpose of adopting medium-voltage distribution in this scenario is to bring the utilization voltage transformation closer to the load in order to benefit of the lower current at higher voltages. Smaller or fewer conductors are required to distribute power at lower current flow. The amount of copper used is reduced by using smaller or fewer conductors, which decreases the cost. Expenditures for conduit and operation are also lower.

The cost of maintaining 2,500 kVA for 100 feet at 480 V with 600 V cable versus running the same amount of power for the same range at 13.2 kV with 15 kV EPR cable is shown in the following example:

  • 480 V, 3,000 A needs eight sets of 3.5-in. conduit, each with three 500 kcmil phase conductors and one 500 kcmil ground conductor, and costs roughly $100,000.
  • One 4-in. conduit with three 2/0 phase conductors and one 2/0 ground conductor are needed to execute 13.2 kV, 110 A for 100 feet, and probably costs $12,000.

The use of medium-voltage distribution also aids in the reduction of voltage drop. Article 215.2 of the National Electrical Code (NEC) prescribes a voltage drop of no more than 5% from the utility service to the load. The basic relationship between voltage drops and power flow is described by Ohm's law (V=IR). The voltage drops increases in proportion to the load current and conductor impedance. Feeders must be expanded to compensate for conductor impedance in low-voltage facilities when the distribution system has long feeder runs. The power flow is smaller in medium-voltage distribution systems, resulting in less voltage drop. This lower voltage drop lessens the need for larger conductors, resulting in a more efficient solution.

When putting conductors underground, another way medium voltage might aid reduce cable sizes is by decreasing or removing ampacity adjustment factors. The cable manufacturers' and the NEC's ampacity figures are based on highly particular parameters. The ambience in which the wires are placed rarely matches those conditions in practise. This difference has a significant effect on the conductors' operating temperatures and serves as the foundation for adjustment parameters. The basic ampacity is changed by these adjustment parameters to fit the cable ampacity in that particular situation.

Secondary metering is another benefit of getting medium power from the utility rather than low voltage (metering on the primary side of the transformation). Primary metering can save up to 5% on kWh charges on average. To assess if primary metering is appropriate for the application, the potential energy rate savings must be weighed against the initial and ongoing costs of maintaining the transformation machinery.

Medium voltage implementation

Any enterprise that uses a significant amount of power, such as data centers and industrial sites, is a good option for medium voltage electricity. Backup generators and redundancy are included in data centre distribution systems to keep the facility functional during outages and eliminate single points of failure. The power distribution system's overall size can be effectively doubled due to the backup power and redundancy. To enhance efficiency, decrease expense, and comply with the NEC's criteria to restrict the number of substations, it's critical to relocate the conversion to voltage supplied (substations) as close to the load as possible.

Functionality, adaptability, and agility are three more key characteristics of data centres that make medium voltage appealing. With the advancement of technology, data centres will evolve and grow. The data centre must be planned in such a manner that it may expand and evolve without being disrupted over time. Multiple smaller power trains (grouped substations, UPS, and generators) enable for growth while lowering upfront construction costs. As the center grows, users can connect more power trains at a lesser cost by using medium-voltage distribution.

Distinctions between low and medium voltage

Operating space, overload protection, and device ratings are some of the key distinctions between low- and medium-voltage systems. These crucial facets must be counted when planning systems above 600V.

  • Operating space - Article 110 of the NEC requires the deepness of the working space in front of low-voltage device to be 3 to 4 ft depending on the formal voltage to base and whether the device on the contrary side of the working space is ungrounded, predicated, or amped. For medium-voltage device, that deepness of working space raises to a range of 3 to 12ft.NEC Article 450 has a precise vault and fire resistance conditions for voltages above35,000 V. To evade the charge of those conditions, voltages lesser than 35,000 V are usually not run into the structure.
  • Safeguard schemes - Another distinction between low-voltage and medium-voltage is overcurrent safeguard. Low-voltage circuit breakers bear both the switching operation and the overcurrent security in one device. Medium-voltage circuit breakers contain only the switching operation to open/ close and don't hold an built-in overcurrent shield device.

Two benefits of using defensive relays in medium-voltage operations are better collaboration and the capability to effortlessly allow discriminative security. In common, protective relays have advanced perfection and a broad range of settings, which allows the engineer to bust the forbearance and exclude belts of lapping between protection- device time-current bends. Differential protection is accounted superior to directional or phase protection due to its selectivity, perceptivity, and speed of operation. It uses the sum-of-all- currents in the zone of safeguard. impeccably, these aggregate equals zero until there's a failing within that zone.

Our Service overview for low and medium voltage distribution

We have been serving the Energy Power industry for many years. we have executed more than 100 projects in different parts of the globe in this industry. We serve our customers in Sub-station Automation Systems (SAS), Remote Terminal Units (RTU), Intelligent Electronic Devices (IED), HMI, testing & commissioning.

As our power allocation systems endure to develop and initiate technically, the need for safety, safeguard and trust ability remains of extreme significance. We support assure the delivery of secure, trustworthy, and affordable electricity to a majority of the world with:

  • Procedures involving thorough testing and evaluation that can benefit you in better understanding risk.
  • Specialized proficiency found around the globe, available when and where you require it most.
  • Services to maneuver and alleviate the impact of flexible origination on grid operations.
  • wide knowledge and understanding of original and public norms and codes makes us a premium resource to regulators.

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We have Platform Independent Engineering Services expertise across Siemens, Rockwell Automation, Honeywell, Schneider Electric, ABB, etc.

Our Energy Automation Services:

  • Develop a business case for substation automation
  • Evaluate existing systems and develop strategies to migrate to new applications and technologies
  • Design an overall solution to integrate substation equipment with communication systems and head-end applications
  • Specify detailed designs and help select all equipment from intelligent devices, substation servers, remote terminal units (RTUs), network switches, firewalls, wide area networks, head-end applications, and others
  • Estimate impacts on utility staff resources during implementation and post-implementation
  • Assist with configuration, integration, and testing of the solution

Enterprise Integration

  • Siemens
    S7- 400 H/ F, 300, S7-1200, S5, S7-1500, Fail-safe Controller, SINAMICS, SIMODRIVE
  • Rockwell Automation
    ControlLogix, CompactLogix, SLC-500 PLC 5, Power Flex drives, GuardLogix, Advance
  • GE Digital
    Working with real engineering systems on real onsite platforms at real project sites
  • Schneider Electric
    Quantum, Premium, M340, Altivar Drives, 1024 I/O multi-rack configuration
  • Honeywell
    MasterLogic, Safety Manager & Fail Safe
  • Mitsubishi
    MELSEC-Q, L & F Series
  • ABB
    AC500, AC800F, ACS 800 Drive

We commenced our technical services in 2015. We have a dedicated team of SCADA engineers who are having vast experience in the power sector, also our engineers undergo training facilities which enable them to acquire a wide range of skills on growing technology needs and achieving customer satisfaction by focusing on quality at work. We undertake Substation Testing and Commissioning of Protection Systems of all types of Relays including Electromechanical to Numerical Relays of all Manufacturers (ABB, Siemens, AREVA).

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