Three design schemes of compensation currents for D-STATCOM in delta connection used for unbalanced load compensation are introduced. They are the schemes based on compensation principle of admittance， no zero sequence component design and an optional design method of maximum minimizing phase current. Comparisons are made considering technical indexes and engineering significance among the proposed three schemes. In serious unbalanced operating conditions， the obvious difference in amplitude among the compensation currents in three phases may lead to one or two phase overloading and the compensation capability is restricted. The optional design makes the compensation currents in three phases to be equal or close to each other as possible as it can， which is helpful to ensure the D-STATCOM having high-usage and desirable compensation effect. Similar performance can be obtained to some extent with the simpler scheme of no zero sequence component design.