Multifunction adaptive controls for tapswitches and capacitors

Apparatus for the direct measurement of the real, P, and imaginary, Q, components of alternating current (AC) electric power using AC voltage and current signals comprising in combination:

• a) microprocessor means including central processors unit (CPU) means, memory means, analog to digital converter (ADC) means, result register means, and analog to digital control logic (ADCTL) means,
• b) said ADC means providing digital samples of positive half cycles of said AC signals,
• c) program including means for setting ADCTL means to continuously sample said AC voltage signals and place results in said result register means,
• d) measurement means operating synchronously with said continuous sampling,
• e) means for providing values of sine functions from a ring of an integral number of sectors of N values per sector with the total number of values equaling the number of samples expected from one full cycle of said AC signal at an expected power frequency,
• f) means for multiplying values from said ring over a selected range of 180.degree. of said ring with samples from said result register as they are taken and summing said samples to measure the fundamental frequency component of said AC voltage signals,
• g) means for setting said ADCTL means for continuous sampling of said AC current and placing results in said result register means,
• h) means for multiplying values from said ring over a first selected range of 360.degree. of said ring with samples from said result register as said samples are taken and summing said products to measure the P component of said AC power, and
• j) means for multiplying values from said ring over a second selected 360.degree. range rotated 90.degree. from said first range with samples from said result register as said samples are taken and summing said products to measure the Q component of said AC power.

Adaptive apparatus for controlling voltage tapchanging switches on load tapchanging (LTC) transformers with secondaries paralleled with each transformer control sensing said transformer load current together with load currents of next paralleled transformers in daisy chain arrangement around rings of said paralleled transformers in an alternating current (AC) power system comprising in combination:

• a) means for sensing first P and Q components of said transformer load current,
• b) means for sensing second P and Q components of said next paralleled transformer load current,
• c) means for controlling said tapswitches so as to maintain ratios of said first P and Q components equal to said second P and Q components
• whereby losses introduced by paralleling are minimized with or without having transformer primaries in parallel.

A system for controlling P and Q components of alternating current (AC) electric power flowing through controlled devices comprising load tapchanging (LTC) transformers and regulators in distribution substations and along distribution power lines extending from said substation comprising in combination:

• a) adaptive tapchanger control (ATC) means for operating said controlled devices in response to AC voltage and current signals as measured at outputs of said controlled devices,
• b) said ATC's including means for changing tapswitch means in said controlled devices to regulate said AC output voltages,
• c) power factor correction capacitor means connected at selected locations along said distribution lines,
• d) adaptive capacitor control (ACC) means for switching said capacitor means on and off of said lines in response to AC voltages measured by said ACC means at said selected locations,
• e) said ATC's further including means for measuring the Q component of said controlled devices' outputs,
• f) said ATC's further including means for changing said regulated output voltages to influence the switching of said capacitors by said ACC's
• to provide the desired voltage and VAr conditions with a minimum combined number of operations of said capacitor means and tapswitch means.

A system for communicating digital data from adaptive tapchanging controls (ATC's) for alternating current (AC) electric power load tapchanging (LTC) transformers and regulators to computers comprising in combination:

• a) said ATC's including means for sending said digital data signals and receiving digital signals requesting said data by radio,
• b) regional stations for two way conversion of said radio digital signals into two way land line digital signals,
• c) said regional stations including means for sending radio commands to selectively request said digital data from said control means,
• d) said ATC's further including means for sending said digital data by radio to said regional station means in response to requests for said data,
• e) a central station for exchanging said land line digital data with more than one said regional station and entering said received digital data into Internet,
• f) computers selectively requesting said digital data via the Internet and obtaining said requested data from said controls via said regional stations and said central station, and
• g) said computers further including means to request and utilize said data
• whereby said control data is accessible from a multiplicity of computers connectable to the Internet.

Apparatus for controlling Var flow in electric power systems including alternating current (AC) distribution lines, voltage control transformer means sending output power into said distribution lines, said apparatus comprising in combination:

• a) first control means for determining a desired voltage to be sent into said distribution lines,
• b) power factor correction capacitor means located at spaced intervals along said distribution lines,
• c) said first control having means for sensing said transformer output voltages and currents and determining the VArs flowing between said transformers and said distribution lines,
• d) second control means for selectively connecting and disconnecting said capacitor means, collapse,
• e) said second control means for connecting said capacitor means after a time determined as a non-linear function of the amount the sensed voltage has been below band edge voltages established below average voltages sensed at said capacitor locations,
• f) said second control means disconnecting said capacitor means after a time determined as a non-linear function of the amount the sensed voltage has been above band edge voltages established above average voltages sensed at said capacitor means locations,
• g) said first control means causing power to be sent temporarily at lower than said desired voltage to influence said second control means to connect said capacitor means to correct said actual Vars flowing to the desired Vars flowing, and
• h) said first control means causing power to be sent temporarily at higher than said desired voltage to influence said second control means to disconnect said capacitor means to correct said actual Vars flowing to the desired Vars flowing.

Apparatus for keeping track of tap positions of load tapchanging transformers (LTCT), including load tapchanger controls (LTC) for controlling tap-switches and tap-switch motor drive relay means, comprising in combination:

• a) first contact means for indicating tap-switch operations,
• b) second contact means for indicating tapswitch operations in the raise direction,
• c) third contact means for indicating tapswitch operations in the lower direction,
• d) at least one fourth contact means settable to indicate selected tap changes,
• e) means for connecting to said first, second, third and fourth contact means,
• f) program means for keeping track of tapswitch positions from operations of said first, second and third contacts, and
• g) program means for keeping records of tap positions.

Power system control relay apparatus to mitigate effects of voltage collapse comprising in combination:

• a) program means for temporarily storing fine grain measurements of AC voltages just prior to a power interruption,
• b) means for permanently storing said measurements when determined to represent an event of voltage collapse, and
• c) means for cross correlating fine grain measurements of AC voltages with permanently stored measurements representing known voltage events
• d) means for distributing said fine grain measurements to experts for determination as to whether said power interruptions were caused by voltage collapse,
• whereby higher levels of cross correlations are indications of impending voltage collapse interruptions.

A method of utilizing many samples of alternating current (AC) voltage signals and AC current signals to directly measure the P and Q components of the flow of AC electric power, the method consisting of the steps of:

• a) taking predetermined numbers of digital samples during positive half cycles of AC voltage signals,
• b) providing tables having double said predetermined number of values of one cycle of a sine wave equally spaced in angle and arranged to be read as a ring starting at any selected point in said ring of values,
• c) obtaining the fundamental component of said voltage signals by summing products of said samples with values from said ring starting at the point where the values change from negative to positive and ending at the point where the values change from positive to negative,
• d) taking double said predetermined number of first samples of current signals,
• e) continuously summing products of said first samples of current signals with values of the sine wave starting at a first point on said ring selected to give the P component of power,
• f) taking double said predetermined number of second samples of current signals, and
• g) continuously summing products of said second samples of current signals with values of the sine wave starting at a second point on said ring spaced 90.degree. from said first point to give the Q component of power.

A method of eliminating requirements for communications from first control means regulating the reduction of higher voltages to intermediate voltages to second control means regulating the switching of power factor capacitors, power lines for distributing power at lower voltages, at higher voltages and at intermediate voltages, power being supplied at the lower voltage to multiple user locations, the network including, at the intermediate voltage, said capacitors with said second control means spaced at locations along said intermediate voltage lines, the method comprising the steps of:

• a) measuring voltages at said capacitor locations and establishing average voltages from said measured voltages,
• b) measuring actual voltages in relation to said average voltages,
• c) varying said capacitor switching times non-linearly faster as voltages deviate away from said average voltages,
• d) changing said average voltages by the measured amounts of voltage change as said capacitors are switched on and off,
• e) selectively changing voltage reductions from said higher to said intermediate voltages so as to maintain desired average voltages, and
• f) selectively further changing said voltage reductions so as to influence capacitor switching times
• whereby capacitors switch to provide voltages closer to said average voltages.