The Department of Energy yesterday set voluntary state-by-state targets for gasoline use during April, May and June in line with the goal President Carter announced last week of holding consumption to no more than 7 million barrels a day in 1980.

The District of Columbia was asked to use 9.8 percent less gasoline than it did in the same three months last year, even though lines at gas stations were at their height last May and June. Only Puerto Rico and Alaska are expected to cut use by greater amounts.

Virginia's target is 3.7 percent below its use in the three months last year, while Maryland's is 4.1 percent lower.

The national target is a 3.4 percent reduction.

Chuck Clinton, the D.C. government's energy chief, expressed unhappiness that "some additional burden is being placed on residents of the District . . . I do not see why there is such a discrepancy between the targets for us and our neighbors.

Clinton added, however, that gasoline sales in the District are now running 8 to 10 percent below a year ago. That could change, as comparisons have to be made with the period in which long lines cut use sharply in 1979.

Before setting the new targets, DOE made several adjustments to actual consumption figures for the second quarter of 1979. They included the trend in gasoline consumption over the last four years, population growth, and previous efforts at conservation.

None of the adjustments helped the District very much, since its adjusted base for the second quarter of last year turned out to be only slightly higher than its actual use.

Nationally, the target set by Carter represents a 6.7 percent cut once all the adjustments are made. That is, if last year had been a normal year, the reduction expected now would be 6.7 percent, not 3.4 percent.

Energy experts were uncertain whether the new national target would require additional measures to discourage use, since higher prices have already caused motorists to cut back.

Meanwhile, gasoline inventories are at record levels, and industry officials are confident that there will be no recurrance of lines at stations this year. Prices, on the other hand, are expected to keep climbing because of higher crude oil costs, increases in gasoline taxes in Virginia and possibly D.C., and the new oil import fee.

While the new targets are voluntary, DOE said it intends to monitor state compliance closely. But it warned that last year's Emergency Energy Conservation Act gives the president authority to make the targets mandatory if he determines that a severe energy supply interruption exists or is imminent. The act defines such a shortage as being at least 8 percent of expected use.

It is up to each state to decide what steps it will take to meet the targets. DOE said it will keep a running total of monthly use to determine whether a state is meeting its target. Also, at any one time, DOE will allow a state a cumulative margin of 2 percent of its annual consumption target before it would be considered out of compliance.

The national target, if met, would mean a 400,000-barrel-a-day cut in gasoline use compared with 1979, or a 5.5 percent reduction for the year as a whole.

Clinton said the District "is examining every possible proposal" for cutting gasoline use, but would mention specifically only attempts to increase car-pooling.

When preliminary targets were announced in December, Virginia and Maryland state energy officials said motorists in their states were already using 7 to 9 percent less than the year before, so that reductions in that range could be met with little difficulty.

After adjustments to normalize the base period, Virginia's target represents a 6.9 percent drop and Maryland's a 7.6 percent decline.