Transmission & Distribution
Electric power transmission or "high voltage electric transmission" is the bulk transfer of electrical energy, from generating plants (historically hydroelectric, nuclear or coal fired but now also wind, solar, geothermal and other forms of renewable energy) to substations located near to population centers. This is distinct from the local wiring between high voltage substations and customers, which is typically referred to as electricity distribution. Transmission lines, when interconnected with each other, become high voltage transmission networks.
Electricity distribution is the final stage in the delivery (before retail) of electricity to end users. A distribution system's network carries electricity from the transmission system and delivers it to consumers. Typically, the network would include medium-voltage (less than 50 kV) power lines, electrical substations and pole-mounted transformers, low-voltage (less than 1 kV) distribution wiring and sometimes electricity meters.
A key limitation in the distribution of electricity is the difficulty in storing significant quantities of electrical energy and in controlling voltage and VAr (volt-ampere reactive) flow. A sophisticated system of control is required to ensure the distribution VAr supply very closely matches the VAr demand. If distribution VAr supply and demand are not in balance, generation plants and transmission equipment must supply and transmit the required VArs. Regional unbalances of power or VAr supply/demand can cause inefficient operation which, in the worst cases, can lead to a major regional blackout.
Beckwith Electric designs and manufactures various Volt/VAr Management products to minimize losses and voltage variations in the distribution system, thus providing maximum power delivery capacity to the end user. Our line of transformer & regulator controls and digital capacitor bank controls provides the following efficiencies:
- Reduced System Losses
- Improved System Stability
- Reduced System-Wide Losses
- Increased Power Delivery Capacity (kW)
- Minimized Voltage Variations
- Maintaining Satisfactory Delivery Voltage
- Reduced Maintenance Costs
- Reduced/Deferred Capital Expenditure
- Reduced Operating Costs
- Flattened Voltage Profiles
- Volt /VAr Management Functions such as Conservation Voltage Control (CVC)
Reduction of system power losses is a fundamental key. Studies have shown that losses in the distribution system approach 8 to 10% and that correct and proper capacitor bank placement and operation can reduce these losses in the distribution system by as much as 10 to 25% or more.
If the annual load of a distribution system was 35.000GWh/yr, 8% losses would equate to 2800GWh/yr. At a cost of $0.05/kWh, the 2800kWh/yr would be a gross $140 million dollars wasted annually! Plus the associated loss of power delivery capacity! If proper and correct Volt/VAr Management Functions, including placement and operation of switched capacitor banks in the distribution system, can conservatively save 15% of those losses, then by rapid assessment it can be seen that annual savings from installing pole top cap banks exceeds 20 million 15% of $140 million = $21 million).
Loss reductions of this magnitude can defer or offset the need for additional generation by freeing up power delivery capacity.
Voltage drop on distribution lines also has a major effect on customer voltage levels. Distribution line capacitor “kVArs” have an influence on this circuit voltage profile that is 3 to 5 times greater than equal variations in kW loads. (with line x/r ratio = 4, 1kw produces a 1 volt drop while 1 kVAr produces a 4 volt drop). With less voltage variations, better voltage delivery to customers can be achieved.
Beckwith Electric also designs and manufactures various intertie, generation and transformer protection relays, that allow the interconnection of distribution systems and the connection of distributed generation. Such interconnections create the capability for more efficient and reliable distribution and transmission systems.
Beckwith’s familiarity with control products and their applications allows our team to rapidly and efficiently assist you with the selection and use of the proper product or engineered system to provide the right solution now and in the future. Beckwith products are specifically designed to meet the challenges of the above applications. We constantly learn and evolve from Standards participation, input from clients and our vast number of installations – 1000’s of units worldwide.