A power control device comprising: measurement means for measuring electrical power supplied to a load; and control means for controlling the power supplied to the load, correction means being for: adding a maximum plus measurement error of the measurement means to the measurement value to calculate a primary correction power value; determining whether the primary correction power value is greater than a power consumption upper limit, the power consumption upper limit being obtained by adding a designed reference power consumption value of the load and its maximum plus tolerance; setting the primary correction power value as the corrected power value in response to a determination that the primary correction power value is not greater than the power consumption upper limit, and setting the power consumption upper limit as the corrected power value in response to a determination that the primary correction power value is greater than the power consumption upper limit so that the corrected power value does not exceed the power consumption upper limit, wherein the control means is for controlling the power supplied to the load based on the corrected power value corrected by the correction means. measurement means for measuring electrical power supplied to a load; and control means for controlling the power supplied to the load, correction means being for: adding a maximum plus measurement error of the measurement means to the measurement value to calculate a primary correction power value; determining whether the primary correction power value is greater than a power consumption upper limit, the power consumption upper limit being obtained by adding a designed reference power consumption value of the load and its maximum plus tolerance; setting the primary correction power value as the corrected power value in response to a determination that the primary correction power value is not greater than the power consumption upper limit, and setting the power consumption upper limit as the corrected power value in response to a determination that the primary correction power value is greater than the power consumption upper limit so that the corrected power value does not exceed the power consumption upper limit, wherein the control means is for controlling the power supplied to the load based on the corrected power value corrected by the correction means. adding a maximum plus measurement error of the measurement means to the measurement value to calculate a primary correction power value; determining whether the primary correction power value is greater than a power consumption upper limit, the power consumption upper limit being obtained by adding a designed reference power consumption value of the load and its maximum plus tolerance; setting the primary correction power value as the corrected power value in response to a determination that the primary correction power value is not greater than the power consumption upper limit, and setting the power consumption upper limit as the corrected power value in response to a determination that the primary correction power value is greater than the power consumption upper limit so that the corrected power value does not exceed the power consumption upper limit, wherein the control means is for controlling the power supplied to the load based on the corrected power value corrected by the correction means.