We report on a power standard for measurement of electrical power of sinusoidal signals based on digitzers and a phase-controlled phantom power source. The voltage channel ranges up to 1000 V at 100 kHz, and 20 V at 1 MHz, the current channel ranges up to 100 A at 100 kHz and 1 A at 1 MHz. The phase can be set arbitrarily ±180 degrees. We present the design of the system, its components and preliminary performance and measurement uncertainties.