Nr Electric Co., Ltd

Nr Engineering Co., Ltd

Weiqun Liu

Wei Yan

Xiangjian Shi

Jun Chen

Quanrong Shen

Guang Wang

Qixue Zhang

Long Wu

A novel reactive power overexcitation regulation technology for synchronous generator, comprises measuring a stator voltage, a stator current, an active power and a reactive power of the synchronous generator; calculating the allowable upper limit value of the reactive power of the generator according to the allowable stator current of stator heating, and calculating the allowable value of the reactive power of the minimum stator current of the generator according to the contact reactance between the generator and the grid; comparing the stator current with its allowable value, calculate the excess calorific value of the stator of the generator if the calculated actual stator current is larger than its allowable value, enter reactive power overexcitation limiting regulation mode if the excess calorific value of the generator reaches the upper limit of the allowable heating margin of the generator; and using the larger value between the allowable upper limit value of the reactive power and the allowable value of the reactive power as the goal value of the reactive power regulation to maintain the output reactive power of the generator equal to the goal value. The present invention can protect the safety of the generator, and is beneficial to support the grid voltage to improve the stability of the power system performance.

Reactive power overexcitation regulation technology for synchronous generator

Embodiments of the present invention disclose a current source converter differential protection method, including: sampling, by a relay protection device, secondary side currents of current transformers on two sides of a protected current source converter, to obtain incomer-side three-phase currents, and outgoer-side three-phase currents; rectifying the incomer-side three-phase currents and the outgoer-side three-phase currents, to obtain an incomer-side input current and an outgoer-side output current which are equivalent; converting the incomer-side input current and the outgoer-side output current according to a current ratio of the current transformers on the two sides, to acquire a transient differential current and a transient restraint current; acquiring a differential current and a restraint current according to the transient differential current and the transient restraint current; and achieving differential protection according to the differential current and the restraint current. The embodiments of the present invention further disclose a relay protection device correspondingly.

Current source converter differential protection method and relay protection device

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Jiangsu, China

Weiqun Liu