Patent ID: 11933825
Assignee: TOSHIBA MITSUBISHI—ELECTRIC INDUSTRIAL SYSTEMS CORPORATION
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 13:
14. The power conversion system according to claim 12, wherein
the frequency calculation circuitry further includes:
a slow rate limiter provided in parallel with the rate limiter, the slow rate limiter limiting a change of the system frequency at a lower change rate than a change rate of the rate limiter; and
a switching circuit selectively switching between a first state in which the rate limiter is used and a second state in which the slow rate limiter is used,
the orthogonal coordinate signal generator generates a voltage signal of an active component of the three-phase alternating current power of the power system by converting the two-phase voltage signal into a voltage signal of a rotating coordinate system, and
the switching circuit selects the first state when an absolute value of a differential of the voltage signal of the active component is less than a prescribed value, and selects the second state when the absolute value of the differential of the voltage signal of the active component is equal to or greater than the prescribed value.