Provided in the present invention are a microgrid control system and a microgrid, the microgrid control system comprising: a grid-connected switch, an energy router, a first controller and a second controller; the first controller controls the grid-connected switch and sends a first control instruction; the second controller receives the first control instruction and responds to the first control instruction for controlling the energy router.

A method and apparatus for secondary control in a power network. In one embodiment, the method comprises determining a frequency area controller error (ACE) equation for an area and a voltage ACE for the area; decomposing the frequency ACE equation and the voltage ACE equation to generate a first set of symmetric sequences for the frequency ACE equation and a second set of symmetric sequences for the voltage ACE equation, respectively, wherein the first and second sets of symmetric sequences represent positive and negative sequences; and implementing, by an area controller for the area, secondary control on each sequence in the first and second sets of symmetric sequences separately.

A method and apparatus for secondary control in a power network. In one embodiment, the method comprises determining a frequency area controller error (ACE) equation for an area and a voltage ACE for the area; decomposing the frequency ACE equation and the voltage ACE equation to generate a first set of symmetric sequences for the frequency ACE equation and a second set of symmetric sequences for the voltage ACE equation, respectively, wherein the first and second sets of symmetric sequences represent positive and negative sequences; and implementing, by an area controller for the area, secondary control on each sequence in the first and second sets of symmetric sequences separately.

A power electronic control-based capacitor to be used at the terminal of a grid-connected wind generator system for improving the transient stability of the generator following a fault in the network. This eliminates the need of adding auxiliary control devices at the grid side. The wind generator terminal capacitor is controlled through power electronics in such a way as to function both at the steady state and transient conditions maintaining the stability of the wind generator. A power electronic control-based terminal capacitor (“C”) is connected through two back-to-back thyristor switching devices, T1 and T2. The function of the capacitor depends on the triggering or firing-angle of the thyristor switches, which varies from 0 degrees to 180 degrees.

A power electronic control-based capacitor to be used at the terminal of a grid-connected wind generator system for improving the transient stability of the generator following a fault in the network. This eliminates the need of adding auxiliary control devices at the grid side. The wind generator terminal capacitor is controlled through power electronics in such a way as to function both at the steady state and transient conditions maintaining the stability of the wind generator. A power electronic control-based terminal capacitor (“C”) is connected through two back-to-back thyristor switching devices, T1 and T2. The function of the capacitor depends on the triggering or firing-angle of the thyristor switches, which varies from 0 degrees to 180 degrees.

The present innovations control and improve operation of one or more microgrids optionally and/or intermittently coupled to an Electric Power System(s).

The present innovations control and improve operation of one or more microgrids optionally and/or intermittently coupled to an Electric Power System(s).

A microgrid power flow monitoring and control system is described herein. The control system may determine active and reactive power sharing shortage on the electric power delivery system. The control system may utilize the control strategies of generation units, such as ISO control, droop control and constant power control to estimate power flow within a microgrid or other isolated system. A control strategy of one or more generators may be modified based on the determined power flow.

The invention provides systems, methods, and devices relating to the provision of system-wide coordinated control voltage regulation support in power transmission and distribution networks using multiple inverter based power generation or absorption facilities, which are coupled to the power transmission and distribution networks for minimizing transmission and distribution line losses and for performing Conservation Voltage Reduction. The invention uses a novel control method of inverter based Distributed Generators as Static Synchronous Compensator (STATCOM) in a way that provides a dynamic voltage regulation/control with the inverter capacity remaining after real power generation or absorption, thereby decreasing system line losses and performing Conservation Voltage Reduction.

Provided are hybrid passive power filter and a three-phase power system. The hybrid passive power filter includes: a series passive harmonic isolation unit, a parallel passive filtering unit, and a harmonic load; the series passive harmonic isolation unit has an input terminal electrically connected to a power grid and an output terminal electrically connected to a first terminal of the harmonic load, and the series passive harmonic isolation unit is configured to isolate harmonics; and the parallel passive filtering unit has an input terminal electrically connected to the output terminal of the series passive harmonic isolation unit and an output terminal electrically connected to a second terminal of the harmonic load, and the parallel passive filtering unit is configured to filter out harmonics.