New smart transformer will push smart grid forward

The new smart transformer can quickly charge the car and reduce the power grid consumption by 3%, which is equivalent to several times the annual US solar panel power generation.

The new semiconductor-based device management grid power makes the "smart grid" smarter. They will quickly charge electric vehicles and allow utilities to consolidate large amounts of solar and wind power without causing power outages or power surges. The developers of these devices are many small institutions, some of which recently received new funds from the Advanced Research Projects Agency Energy Agency (ARPA-E) and the National Science Foundation.

Smart Transformer: A prototype of a smart solid-state electronic transformer developed by the Electric Power Research Institute. It is smaller and more versatile than today's transformers. The left module converts the high-voltage alternating current from the grid into direct current. On the right is a transformer that converts electricity into 120 volts AC, which is the standard wall outlet voltage. The right socket is the other two interfaces, one is 240 volts alternating current and the other is 400 volts direct current.

Utilities start to launch smart grids, which are focused on collecting information, such as measuring smart meters used in time to install electricity in homes and businesses. However, with the development of smart grids, they will add devices such as smart solid-state transformers, which will strengthen the control of the line power flow, said Alex Huang, a research center of the National Research Foundation. The director of this center will develop such equipment. "If the smart meter is the brain of a smart grid," he said, "solid-state transformer equipment is muscle." These devices will help change the grid, the original system power flow is one-way, that is, from the power station to the consumer, change After the system, owners and companies also generally generate electricity.

Today's transformers are single-function devices. They change the voltage from one level to another, such as from a high voltage to a low voltage, and the high voltage is the home's 120-volt or 240-volt power distribution level. The new solid-state transformer is much more flexible. They use transistors and diodes and other semiconductor-based devices, unlike the transistors used in computer chips, which are designed to handle high power levels and very fast switching. According to the signals of utility companies or households, they can change the voltage and other characteristics of the electricity they produce. They can output AC or DC power, or be integrated into AC and DC power from wind turbines and solar panels, and change the frequency and voltage to suit the needs of the grid. They have processors and built-in communications hardware that can connect utility operators, as well as other smart transformers and consumers.

This device is very flexible, and researchers are still studying how to use it best. There are several possibilities. Today, it takes many hours to recharge an electric car at home. Even if a dedicated charger is plugged in with a 220/240 volt circuit instead of the more common 110/120 volt outlet, it is slow. DC charger charging can save time, charging a battery full of 24 kilowatt hours, like the battery in the new Nissan Leaf, can be reduced from 8 hours to 30 minutes, but they are not efficient, it will waste about 10% to 12% of electricity is electricity that is charged. The new transformers can replace these dedicated chargers, and they are more efficient, wasting only about four percent of the electricity, said Arindam Maitra, senior project manager at the Electric Power Research Institute. This research institute is developing a smart transformer.

More importantly, because of the communication and processing capabilities of this type of transformer, if several neighbors switch on their cars while charging, the transformer can prevent the circuit from being overloaded because it can slow down or postpone charging, which is based on consumer preferences and Public utility price signal. The same equipment can also be used to deliver direct current, which is transmitted from the solar panels to the grid, which will abandon some of the equipment that is currently used to convert the power of solar panels and eliminate voltage fluctuations. These fluctuations may not be eliminated. Causes the panel to disconnect and stops generating electricity.

Power users such as large warehouse-type supermarkets are beginning to install more solar panels and storage equipment, so smart transformers are the key, because the electricity to be integrated comes from these sources and the power grid, Mettle said. Storage systems and distributed energy sources allow stores to determine when to draw electricity from the grid and when to send electricity to the grid, depending on the price of electricity at a particular moment. Smart transformers can coordinate this rapid change in voltage, which is the change from buying electricity to selling electricity, while keeping the grid stable and preventing the neighbor's lights from dimming. They can even allow people to buy electricity from their neighbors, Alex Huang said. "If you plug in an electric car at night, you can negotiate with some neighbors if you charge, if neighbors have excess power," he said. "You can actually pay for a neighbor. You don't have to pay for the utility."