A flicker measurement apparatus comprising: at least one light source; a signal input/output module connected to at least one power supply unit, PSU, the PSU adapted to supply a dimming signal based on a dimming control signal received through the signal input/output module to the at least one light source; a light detecting module adapted to detect a light emitted from the at least one light source; a signal processing module adapted to convert the detected light into an electrical signal; and a control module; characterized in that the signal processing module is further adapted to process the electrical signal so as to generate a frequency signal comprising an alternating current, AC, component and a direct current, DC component; and the control module comprises: a first controller adapted to generate the dimming control signal, a signal transmitter adapted to transmit the dimming control signal to the signal input/output module, a signal receiver adapted to receive the frequency signal from the signal processing module, and a second controller adapted to separate the AC component and the DC component from the frequency signal, to compute a ratio of the AC component to the DC component as a measurement of flicker of the at least one light source, and to determine a state of the at least one PSU based on the computed ratio, wherein when the computed ratio is less than a predetermined threshold, the second controller determines the at least one PSU to be in a normal state, and when the computed ratio is equal to or greater than the predetermined threshold, the second controller determines the at least one PSU to be in an abnormal state. at least one light source; a signal input/output module connected to at least one power supply unit, PSU, the PSU adapted to supply a dimming signal based on a dimming control signal received through the signal input/output module to the at least one light source; a light detecting module adapted to detect a light emitted from the at least one light source; a signal processing module adapted to convert the detected light into an electrical signal; and a control module; characterized in that the signal processing module is further adapted to process the electrical signal so as to generate a frequency signal comprising an alternating current, AC, component and a direct current, DC component; and the control module comprises: a first controller adapted to generate the dimming control signal, a signal transmitter adapted to transmit the dimming control signal to the signal input/output module, a signal receiver adapted to receive the frequency signal from the signal processing module, and a second controller adapted to separate the AC component and the DC component from the frequency signal, to compute a ratio of the AC component to the DC component as a measurement of flicker of the at least one light source, and to determine a state of the at least one PSU based on the computed ratio, wherein when the computed ratio is less than a predetermined threshold, the second controller determines the at least one PSU to be in a normal state, and when the computed ratio is equal to or greater than the predetermined threshold, the second controller determines the at least one PSU to be in an abnormal state. a first controller adapted to generate the dimming control signal, a signal transmitter adapted to transmit the dimming control signal to the signal input/output module, a signal receiver adapted to receive the frequency signal from the signal processing module, and a second controller adapted to separate the AC component and the DC component from the frequency signal, to compute a ratio of the AC component to the DC component as a measurement of flicker of the at least one light source, and to determine a state of the at least one PSU based on the computed ratio, wherein when the computed ratio is less than a predetermined threshold, the second controller determines the at least one PSU to be in a normal state, and when the computed ratio is equal to or greater than the predetermined threshold, the second controller determines the at least one PSU to be in an abnormal state.