Reactive Power Compensation Controller Voltage Stability
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Solution Overview
Problem
Existing reactive power compensation methods in electrical power networks often lead to excessive operation of voltage regulating devices, increased maintenance, and sub-optimal utilization of dynamic capabilities due to undesirable interactions with other reactive power sources and voltage regulating devices, resulting in unnecessary losses.
Innovation Solution
A system and method for selective reactive power compensation using compensation factors (CFs) determined by voltage values at the point of interconnection, where a controller computes a first reactive power value, compares it with pre-defined voltage limits, and adjusts reactive power output based on CFs to minimize voltage variations induced by power sources, reducing unnecessary compensation and losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If closed-loop voltage control is used to mitigate voltage variation, then voltage stability is improved, but losses in the reactive power source increase and dynamic capabilities are sub-optimally utilized
Solution Approach 1:
The controller changes the control parameter from voltage-based feedback to active power-based feedforward control. By using Q-P characteristics where reactive power Q is calculated as a function of active power P injected by the power source, the system compensates only for self-induced voltage variations rather than all voltage variations, thereby reducing unnecessary reactive power output and losses in the reactive power source.
2Stability of the object's composition
If reactive power is varied according to Q-V characteristics to compensate for voltage variations, then voltage stability is improved, but undesirable interactions with other reactive power sources and voltage regulating devices occur
Solution Approach 1:
The invention extracts and compensates only the self-induced voltage variation component from the total voltage variation. By using Q-P characteristics, the controller isolates the voltage variation caused by the power source's own active power injection and compensates only for that specific component, leaving other voltage variations (caused by loads and other generating devices) uncompensated. This selective approach eliminates undesirable interactions with other reactive power sources and voltage regulating devices in the network.
3Loss of energy
If reactive power is varied according to Q-P characteristics to compensate for self-induced voltage variation, then losses are reduced, but voltage rise during low voltage conditions may be compensated unnecessarily
Solution Approach 1:
The invention introduces voltage measurement feedback at the point of interconnection (POI) to complement the Q-P characteristics approach. The controller measures the actual voltage at the POI and uses this information to determine whether reactive power compensation is actually needed. This feedback mechanism allows the system to distinguish between voltage variations that require compensation and those that do not, such as beneficial voltage rise during peak load conditions, thereby avoiding unnecessary compensation and improving network efficiency.
Data Source
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AI summary
A method for compensating self-induced voltage variations includes computing a first reactive power value (Q1), obtaining a voltage value at a point of interconnection (POI) between at least one power source and a power grid, comparing the voltage value with one or more pre-defined voltage limits, computing at least one compensation factor (CF) corresponding to at least one portion of the first reactive power value (Q1) based on an output of the comparison between the voltage value and the one or more pre-defined voltage limits, computing a second reactive power value (Q2) as a function of the at least one portion of the first reactive power value (Q1) and the at least one CF, generating a reactive power compensation command based on the computed second reactive power value (Q2), and transmitting the reactive power compensation command to a power converter.