Electronics Weekly Electronics Design & Components Tech News
A plug-in hybrid electric vehicle (PHEV) requires a power electronic system between the power grid and the high-voltage battery pack located inside the vehicle. This electronic system is split into two parts: a charging station, which is also called electric vehicle service equipment (EVSE) or an off-board charger, and an onboard charger inside the vehicle.
A charging station is part of the grid infrastructure installed along a street, parking lot or in a home garage; its primary purpose is to supply the power to the PHEV for charging the battery. An onboard charger is responsible for the final stage of charging the battery pack. It takes the AC power source from the EVSE and transforms the power into the required battery-charging profile.
Despite having separate functions for charging a vehicle, similarities in the naming conventions (“on-” and “off-” board chargers) have caused general confusion about these two types of systems. While the onboard charger has to condition (convert to high-voltage DC) power from the off-board AC charger (Figure 1) before supplying it to the battery management system (BMS), the off-board DC charger works without an onboard charger and interfaces directly with the BMS.
In this paper, we will attempt to explain onboard chargers, how they work and why they’re used. We will also explain charging stations and how they interact with onboard charger and EV BMS systems, along with various power-architecture implementations.
Stay ahead of the energy storage and solar game with bidirectional PFC and hybrid inverter solutions
Now coming out of its infancy, the residential energy storage market is on the brink of explosive growth. In the U.S. alone, this market has had 232% year-on-year growth since the first quarter of 2018, with behind-the-meter storage making up 46% of deployments in the first quarter of 2019. Today, the residential energy storage sector is comparatively smaller than utility-scale deployments. This global market is expected to grow from an estimated $6 billion in 2019 to $17.5 billion by 2024; that’s a compound annual growth rate of 22.88% (according to the latest Wood Mackenzie U.S. Energy Storage Monitor.
Companies worldwide have started to see the future growth potential for energy storage, with new players from a range of backgrounds and expertise entering the market.
A crucial design challenge for energy storage developers to overcome is system integration to ultimately enable lower system costs, smaller form factors and reduced number of components and subsystems. In the context of energy storage, system integration means combining two separate paths to charge and discharge the battery into one by moving from unidirectional to bidirectional power conversion stages.
Read more in our technical article
Benefits of using Sub-1 GHz connectivity for grid asset monitoring, protection and control
The evolution of the power grid necessitates the addition of wireless connectivity to existing wired connectivity for asset monitoring and control. The primary contributing factors for adding wireless connectivity include:
Adoption of decentralized microgrid model with distributed energy resources along with conventional generation, transmission and distribution.
The heightened need for health and status monitoring of remote power distribution and automation assets supervising the primary equipment to optimize power management; resource allocation; and fault location, isolation and service restoration (FLISR). Remote monitoring of the electrical network helps enable efficient operation of the power grid, reducing number of power outages and power outage time minimizing losses.
Data analytics of grid assets can help operators quickly identify faults while also enabling predictive maintenance for primary equipment, which is nearly nonexistent today. Deciding which specific wireless technology to employ, such as Sub-1 GHz, Bluetooth® Low Energy, Wi-Fi® or multi-standard protocols depends on factors such as data, bandwidth, distance between nodes, the number of connections needed, available power and the required response time.
Read more in our technical article
Enabling and integrating wired and wireless technologies for grid interoperability
If you want to know how old a tree is, you count its rings. If you want to know how old a power distribution grid is, find its oldest component – it’s likely been there for decades.
In fact, many grid components go back farther than 50 years. Some of these original mission-critical pieces still work, and thanks to an “if it ain’t broke, don’t fix it” philosophy, a key challenge in grid evolution is how to achieve interoperability. How do you incorporate tried-and-true technologies such as the RS-232 and RS-485 wired connectivity while continuing the transition to the latest Ethernet technologies and adopting wireless technologies such as Sub-1 GHz, Bluetooth® and Wi-Fi®? As the Internet of Things (IoT) in grid evolves, most of the underlying wired and wireless technologies necessary for creating a smart grid are well established. What’s needed is a framework to bring them all together.
How to Detect and Harden an Electricity Meter Against Tampering by Neutral Disconnection
Energy theft poses a significant challenge in the utility industry and can financially impact both utility companies and end consumers.
Accurately billing consumers for their electricity use requires that electricity meters measure energy consumption under normal operation and detect possible tampering to help prevent electricity theft.
Energy can be stolen through different meter tampering techniques to prevent meters from accurately registering consumption. One technique disconnects the neutral from a meter and connects the consumer’s load to earth instead. Hardening electricity meters against this technique is a proactive approach to reduce tampering and help prevent theft. Electricity meters must be able to either detect neutral disconnections and other types of tampering, or be hardened to prevent energy theft.
Learn more with these design resources:
- SAE J1772-compliant electric vehicle service equipment reference design for level 1 and 2 EV charger
- Bi-directional, dual active bridge reference design for level 3 electric vehicle charging stations
- Three-level, three-phase SiC AC-to-DC converter reference design
- 10kW 3-phase 3-level T-tie inverter reference design for solar string inverter
