Frank as a followup to this post, the following:
“ We need new tests and standards to prevent major failures”
The transition to renewable energy is accompanied by the widespread use of power electronics, such as inverters, which require a whole new way of testing smart equipment, says Theo Bosma, Program Director Power Systems & Electrification at DNV GL, one of the largest technical consultancies in the world. According to Bosma, the new power electronics are not adequately tested at the moment. “New technologies such as solar, wind, batteries and smart grids are driven by software. But as a sector we are still testing individual components instead of the brains of these systems.” He warns that “if we don’t change our methods and standards, this will cause major problems in the future, including blackouts”. DNV GL calls on the electricity sector to jointly develop new industry standards based on “hardware-in-the-loop” techniques.
- With the electric power system increasingly being taken over by software-driven “power electronics”, Theo Bosma, who leads a team of 20 researchers in labs in Singapore, Bristol, Copenhagen, Oslo and Arnhem, has a practical example showing how things can go seriously awry. In the business this is known as “the German 50.2 Hz problem”.
What happened was that in the southern part of Germany solar panels would all shut down when the frequency exceeded 50.2 Hz (this happens when the sun starts shining and all panels together produce too much electricity), and would all start producing again once the frequency went back to 50 Hz, after which they would all shut down again. This yo-yo effect was the result of many inverters reacting simultaneously to signals from the system. “Individually they all did what they had to do”, says Bosma, “but in combination the result was not what was expected or wanted.”
- Another example Bosma encountered in which “smart” components showed unexpected reactions was in the case of a medium-voltage transformer which contained power electronics keeping the voltage at a constant level. “This worked so well that a similar transformer a few kilometres away was put in place. But then the two started hunting each other. If one reduced the voltage, the other started increasing it, because there was no communication or coordination.”
Jim |
