Federal Reserve Chairman Jerome Powell said Tuesday that he sees no need to drop the central bank’s current gradual approach to raising interest rates. Powell said the combination of steady, low inflation and very low unemployment shows the country is going through “extraordinary times.” The central bank is trying to make sure it doesn’t raise rates too quickly and push the country into a recession, or move too slowly and set off higher inflation, he said. He added that the Fed’s goal of gradual increases in interest rates is an effort to balance those risks and extend the current expansion, now the second longest in U.S. history. Powell’s comments, delivered to the annual conference of the National Association of Business Economics, came a week after the central bank approved a third quarter-point hike in its benchmark policy rate, pushing it to a level of 2 percent to 2.25 percent. It …