A voltage error correction system includes a voltage converter, a first and a second analog to digital converters, a subtracter, an adder, and a digital voltage generator. The voltage converter adjusts an input voltage proportionally, adds the adjusted input voltage to a reference voltage to obtain a positive voltage, and outputs the positive voltage. The first analog to digital converter converts the positive voltage into a first digital voltage, the second analog to digital converter converts the reference voltage into a second digital voltage, the subtracter subtracts the second digital voltage from the first digital voltage and outputs a difference voltage, and the adder outputs a corrected voltage by adding the difference voltage of the subtracter to a compensation voltage.