Load management system and method for managing loads in a power distribution grid

Patent metadata

Field	Value
Publication number	US-11919417-B2
Application number	US-202017094043-A
Country	US
Kind code	B2
Filing date	Nov 10, 2020
Priority date	Nov 11, 2019
Publication date	Mar 5, 2024
Grant date	Mar 5, 2024

Abstract

A load management system for managing loads in a power distribution grid. The load management system includes a control unit and at least two current transformers, which are each connected to the control unit by a signal cable. A first current transformer of the at least two current transformers is arranged in the power distribution grid such that the first current transformer is suitable for measuring a current level that is dominant in a grid connecting line of the power distribution grid, which grid connecting line is connected to a power supply company. A second current transformer of the at least two current transformers is arranged in the power distribution grid such that the second current transformer is suitable for measuring the current level that is dominant in a power line of the power distribution grid, which power line feeds at least one charging station of the power distribution grid.

First claim

What is claimed:

1. A load management system for managing loads present in a power distribution grid, said load management system comprising:
a control unit;
at least three current transformers that are each connected to the control unit by a signal cable; and
a power-generating device connected to a supply line for the power distribution grid, wherein the power-generating device is a renewable power source for at least one charging station of the power distribution grid,
wherein:
a first current transformer of the at least three current transformers is arranged in the power distribution grid such that said first current transformer is configured for measuring a current level in a three-phase grid connecting line of the power distribution grid, said three-phase grid connecting line is-being connected to a power supply company,
a second current transformer of the at least three current transformers is arranged in the power distribution grid such that said second current transformer is configured for measuring a current level in a first power line of the power distribution grid, said first power line feeding the at least one charging station of the power distribution grid,
a third current transformer of the at least three current transformers is arranged in the power distribution grid and configured for measuring a current level in a second supply line for the power distribution grid, said second supply line being connected to the power-generating device via the third current transformer, and being configured to feed the at least one charging station of the power distribution grid as a primary power source,
wherein the control unit is configured to:
detect which individual phase of the three-phase grid connecting line supplies power to the at least one charging station of the power distribution grid by supplying a predetermined current level on a specific phase of the three-phase grid connecting line and measuring a reduced predetermined current level on the specific phase.

2. The load management system as claimed in claim 1 , wherein the control unit comprises a voltage measuring device configured for measuring a voltage that is present on a current phase of the three-phase grid connecting line.

3. The load management system as claimed in claim 2 , wherein the control unit is further configured to automatically detect an active power factor by using the first current transformer, the second current transformer, the third current transformer, and the voltage measuring device.

4. The load management system as claimed in claim 1 , wherein the current transformers are analog current transformers.

5. The load management system as claimed in claim 1 , wherein the control unit furthermore comprises a communication module for wired communication and/or for communication by way of radio signals.

6. The load management system as claimed in claim 5 , wherein the second current transformer is an internal current transformer inside the charging station, wherein measurement data obtained by the second current transformer are transmittable to the communication module of the control unit, by way of powerline communication.

7. The load management system as claimed in claim 1 , wherein the power-generating device comprises a photovoltaic installation connected in the power distribution grid.

8. The load management system as claimed in claim 1 , further comprising a load forecast and a solar power forecast, the load forecast and the solar power forecast contributing to a learned load behavior of the power distribution grid.

9. The load management system as claimed in claim 8 , wherein the learned load behavior combines present current and voltage values and weather data.

10. The load management system as claimed in claim 1 , wherein the control unit is further configured to perform asymmetric charging of an electrically operated motor vehicle based on which individual phase of the three-phase grid connecting line supplies power to the at least one charging station of the power distribution grid.

11. The load management system as claimed in claim 1 , wherein the control unit is further configured to perform an automatic phase detection by supplying the predetermined current level on the specific phase of the three-phase grid connecting line and measuring the reduced predetermined current level on the specific phase by one of the at least three current transformers, wherein the reduced predetermined current level on the specific phase indicates that one of the at least three current transformers is fed by the specific phase.

12. A method for controlling a load management system for managing loads present in a power distribution grid, said load management system including a control unit and at least three current transformers, which are each connected to the control unit by a signal cable, wherein a first current transformer of the at least three current transformers is arranged in the power distribution grid such that said first current transformer is configured for measuring a current level in a three-phase grid connecting line of the power distribution grid, said three-phase grid connecting line being connected to a power supply company, wherein a second current transformer of the at least three current transformers is arranged in the power distribution grid such that said second current transformer is configured for measuring a current level in a first power line of the power distribution grid, which first power line feeds at least one charging station of the power distribution grid, and wherein a third current transformer of the at least three current transformers is arranged in the power distribution grid and configured for measuring a current level in a second supply line for the power distribution grid, said second supply line being connected to a power-generating device connected to the second supply line for the power distribution grid, the method comprising:
continuously measuring the current level in the three-phase grid connecting line by way of the first current transformer;
reducing a charging current of the charging station if the current level measured in the three-phase grid connecting line is above a predetermined first threshold value;
deactivating the charging station when the charging current is below a predetermined minimum charging current;
continuously measuring the current level in the second supply line for the power distribution grid, by way of the third current transformer;
detecting which individual phase of the three-phase grid connecting line supplies power to the at least one charging station of the power distribution grid by supplying a predetermined current level on a specific phase of the three-phase grid connecting line and measuring a reduced predetermined current level on the specific phase;
switching the charging current of the charging station to the power-generating device connected to the second supply line for the power distribution grid, wherein the power-generating device is a renewable power source for the charging station and wherein the power-generating device is connected to the second supply line for the power distribution grid via the third current transformer; and
using renewable power from the renewable power source as a primary power source for the charging station.

13. The method as claimed in claim 12 , further comprising reducing the charging current of the charging station and/or disconnecting the charging station when an electricity tariff that applies to the three-phase grid connecting line is a peak tariff.

14. The method as claimed in claim 12 , further comprising increasing the charging curre

Assignees

• Porsche Ag

Inventors

• Heyne Raoul
• Schneider-Schaper Alexander
• Rezac Martin
• Sole Barry
• Chodura Hartmut
• Schlieben Ulf
• Rohilla Sunny

Classifications

• H02J2105/52

  for limitation of the power consumption in the networks or in one section of the networks, e.g. load shedding or peak shaving · CPC title

• B60L53/68 Primary

  Off-site monitoring or control, e.g. remote control · CPC title

• B60L53/11

  DC charging controlled by the charging station, e.g. mode 4 · CPC title

• B60L53/30

  Constructional details of charging stations · CPC title

• B60L53/51

  Photovoltaic means · CPC title